diff --git a/test/built-ins/Number/string-numeric-separator-literal-bil-bd-nsl-bd.js b/test/built-ins/Number/string-numeric-separator-literal-bil-bd-nsl-bd.js
new file mode 100644
index 0000000000000000000000000000000000000000..748c90a1e1414b4bf33b40ccbfe5c42bded9cdb1
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-bil-bd-nsl-bd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0b` | `0B` BinaryDigit NumericLiteralSeparator BinaryDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+---*/
+
+assert.sameValue(Number("0b0_1"), 0b01);
+assert.sameValue(Number("0B0_1"), 0B01);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-bil-bd-nsl-bds.js b/test/built-ins/Number/string-numeric-separator-literal-bil-bd-nsl-bds.js
new file mode 100644
index 0000000000000000000000000000000000000000..71dca2627d9df5d7f376af56f54d0b83204f643d
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-bil-bd-nsl-bds.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0b` | `0B` BinaryDigit NumericLiteralSeparator BinaryDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+---*/
+
+assert.sameValue(Number("0b0_10"), 0b010);
+assert.sameValue(Number("0B0_10"), 0B010);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-bil-bds-nsl-bd.js b/test/built-ins/Number/string-numeric-separator-literal-bil-bds-nsl-bd.js
new file mode 100644
index 0000000000000000000000000000000000000000..0b875e4af3d6b37eb1a039a7043baa7855ae1db6
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-bil-bds-nsl-bd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0b` | `0B` BinaryDigits NumericLiteralSeparator BinaryDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+---*/
+
+assert.sameValue(Number("0b01_0"), 0b010);
+assert.sameValue(Number("0B01_0"), 0B010);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-bil-bds-nsl-bds.js b/test/built-ins/Number/string-numeric-separator-literal-bil-bds-nsl-bds.js
new file mode 100644
index 0000000000000000000000000000000000000000..09e40465c6a0e3824e51b84b755401516452c56b
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-bil-bds-nsl-bds.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0b` | `0B` BinaryDigits NumericLiteralSeparator BinaryDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+---*/
+
+assert.sameValue(Number("0b01_00"), 0b0100);
+assert.sameValue(Number("0B01_00"), 0B0100);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dd-nsl-dd.js b/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dd-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..3ec1c859a8a0e07c1e6af96004c6af2b0922693d
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dd-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ DecimalDigits `.` DecimalDigits ExponentPart_opt `-` DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ SignedInteger ::
+ ...
+ - DecimalDigits
+ ...
+
+---*/
+
+assert.sameValue(Number("1.0e-1_0"), 1.0e-10);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dds-nsl-dd.js b/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..489e27e2879029eef23613902dfff4bf56704700
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dds-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ DecimalDigits `.` DecimalDigits ExponentPart_opt `-` DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ SignedInteger ::
+ ...
+ - DecimalDigits
+ ...
+
+---*/
+
+assert.sameValue(Number("1.0e-10_0"), 1.0e-100);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dd-nsl-dd.js b/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dd-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..de2f3b67bdd6f739dbdd5a3fa348fecb149a7ba4
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dd-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ DecimalDigits `.` DecimalDigits ExponentPart_opt `+` DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ SignedInteger ::
+ ...
+ + DecimalDigits
+ ...
+
+---*/
+
+assert.sameValue(Number("1.0e+1_0"), 1.0e+10);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dds-nsl-dd.js b/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..dc1b9fa34cfc734705d6b191f08dd8c4d6306f5e
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dds-nsl-dd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ DecimalDigits `.` DecimalDigits ExponentPart_opt `+` DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ SignedInteger ::
+ ...
+ + DecimalDigits
+ ...
+
+---*/
+
+assert.sameValue(Number("1.0e+10_0"), 1.0e+100);
+
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dd-nsl-dd-one-of.js b/test/built-ins/Number/string-numeric-separator-literal-dd-nsl-dd-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..8f532ab3ea10405ed6de3c421c0935c570b969b7
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dd-nsl-dd-one-of.js
@@ -0,0 +1,34 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: NonZeroDigit NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+
+ DecimalDigit :: one of
+ 0 1 2 3 4 5 6 7 8 9
+
+---*/
+
+assert.sameValue(Number("1_0"), 10);
+assert.sameValue(Number("1_1"), 11);
+assert.sameValue(Number("1_2"), 12);
+assert.sameValue(Number("1_3"), 13);
+assert.sameValue(Number("1_4"), 14);
+assert.sameValue(Number("1_5"), 15);
+assert.sameValue(Number("1_6"), 16);
+assert.sameValue(Number("1_7"), 17);
+assert.sameValue(Number("1_8"), 18);
+assert.sameValue(Number("1_9"), 19);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dds-dot-dd-nsl-dd-ep-dd.js b/test/built-ins/Number/string-numeric-separator-literal-dds-dot-dd-nsl-dd-ep-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..3928f9e034843c45ef3b96f35d97e72cbaa83a2f
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dds-dot-dd-nsl-dd-ep-dd.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ DecimalDigits `.` DecimalDigits NumericLiteralSeparator DecimalDigits
+ ExponentPart SignedInteger
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+---*/
+
+assert.sameValue(Number("10.00_01e2"), 10.0001e2);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dds-nsl-dd.js b/test/built-ins/Number/string-numeric-separator-literal-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..4ce91e862b0940aa052903a0cace24e8a45c71ce
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dds-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: DecimalDigits NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+---*/
+
+assert.sameValue(Number("123456789_0"), 1234567890);
+assert.sameValue(Number("123456789_1"), 1234567891);
+assert.sameValue(Number("123456789_2"), 1234567892);
+assert.sameValue(Number("123456789_3"), 1234567893);
+assert.sameValue(Number("123456789_4"), 1234567894);
+assert.sameValue(Number("123456789_5"), 1234567895);
+assert.sameValue(Number("123456789_6"), 1234567896);
+assert.sameValue(Number("123456789_7"), 1234567897);
+assert.sameValue(Number("123456789_8"), 1234567898);
+assert.sameValue(Number("123456789_9"), 1234567899);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dot-dd-nsl-dd-ep.js b/test/built-ins/Number/string-numeric-separator-literal-dot-dd-nsl-dd-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..e3b1c415004fca03a5daee407846130bc973781c
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dot-dd-nsl-dd-ep.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `.` DecimalDigit NumericLiteralSeparator DecimalDigit ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+---*/
+
+assert.sameValue(Number(".0_1e2"), .01e2);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dot-dd-nsl-dds-ep.js b/test/built-ins/Number/string-numeric-separator-literal-dot-dd-nsl-dds-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..eb5ad47b25da12792362a34ff37663c26cf55c5c
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dot-dd-nsl-dds-ep.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `.` DecimalDigit NumericLiteralSeparator DecimalDigits ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+---*/
+
+assert.sameValue(Number(".1_01e2"), .101e2);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dot-dds-nsl-dd-ep.js b/test/built-ins/Number/string-numeric-separator-literal-dot-dds-nsl-dd-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..87f436fa6882974a48b763cbe0859a8515b21b51
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dot-dds-nsl-dd-ep.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `.` DecimalDigits NumericLiteralSeparator DecimalDigit ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+---*/
+
+assert.sameValue(Number(".10_1e2"), .101e2);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-dot-dds-nsl-dds-ep.js b/test/built-ins/Number/string-numeric-separator-literal-dot-dds-nsl-dds-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..fccfc7a0e0ab10b97971f5203465fa27c6e848d1
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-dot-dds-nsl-dds-ep.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `.` DecimalDigits NumericLiteralSeparator DecimalDigits ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+---*/
+
+assert.sameValue(Number(".00_01e2"), .0001e2);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-hil-hd-nsl-hd.js b/test/built-ins/Number/string-numeric-separator-literal-hil-hd-nsl-hd.js
new file mode 100644
index 0000000000000000000000000000000000000000..ffa72cd660d971d7262d6a6c2326a9923854d25d
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-hil-hd-nsl-hd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0x` | `0X` HexDigit NumericLiteralSeparator HexDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+---*/
+
+assert.sameValue(Number("0x0_1"), 0x01);
+assert.sameValue(Number("0X0_1"), 0X01);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-hil-hd-nsl-hds.js b/test/built-ins/Number/string-numeric-separator-literal-hil-hd-nsl-hds.js
new file mode 100644
index 0000000000000000000000000000000000000000..300ab9e9605151e18382c34edcd943e33f77767e
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-hil-hd-nsl-hds.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0x` | `0X` HexDigit NumericLiteralSeparator HexDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+---*/
+
+assert.sameValue(Number("0x0_10"), 0x010);
+assert.sameValue(Number("0X0_10"), 0X010);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-hil-hds-nsl-hd.js b/test/built-ins/Number/string-numeric-separator-literal-hil-hds-nsl-hd.js
new file mode 100644
index 0000000000000000000000000000000000000000..bdfb33c0cfc8daf0547cc0d053fdd593aff68fca
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-hil-hds-nsl-hd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0x` | `0X` HexDigits NumericLiteralSeparator HexDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+---*/
+
+assert.sameValue(Number("0x01_0"), 0x010);
+assert.sameValue(Number("0X01_0"), 0X010);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-hil-hds-nsl-hds.js b/test/built-ins/Number/string-numeric-separator-literal-hil-hds-nsl-hds.js
new file mode 100644
index 0000000000000000000000000000000000000000..e379ab2c029d596ed70afb2c68929666ffd9be2c
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-hil-hds-nsl-hds.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0x` | `0X` HexDigits NumericLiteralSeparator HexDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+---*/
+
+assert.sameValue(Number("0x01_00"), 0x0100);
+assert.sameValue(Number("0X01_00"), 0X0100);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-hil-od-nsl-od-one-of.js b/test/built-ins/Number/string-numeric-separator-literal-hil-od-nsl-od-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..ded211717bbdcfa05a0ec6d4d69010b6d27443c2
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-hil-od-nsl-od-one-of.js
@@ -0,0 +1,47 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0x` | `0X` HexDigit NumericLiteralSeparator HexDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+---*/
+
+assert.sameValue(Number("0x0_0"), 0x00);
+assert.sameValue(Number("0x1_1"), 0x11);
+assert.sameValue(Number("0x2_2"), 0x22);
+assert.sameValue(Number("0x3_3"), 0x33);
+assert.sameValue(Number("0x4_4"), 0x44);
+assert.sameValue(Number("0x5_5"), 0x55);
+assert.sameValue(Number("0x6_6"), 0x66);
+assert.sameValue(Number("0x7_7"), 0x77);
+assert.sameValue(Number("0x8_8"), 0x88);
+assert.sameValue(Number("0x9_9"), 0x99);
+assert.sameValue(Number("0xa_a"), 0xaa);
+assert.sameValue(Number("0xb_b"), 0xbb);
+assert.sameValue(Number("0xc_c"), 0xcc);
+assert.sameValue(Number("0xd_d"), 0xdd);
+assert.sameValue(Number("0xe_e"), 0xee);
+assert.sameValue(Number("0xf_f"), 0xff);
+assert.sameValue(Number("0xA_A"), 0xAA);
+assert.sameValue(Number("0xB_B"), 0xBB);
+assert.sameValue(Number("0xC_C"), 0xCC);
+assert.sameValue(Number("0xD_D"), 0xDD);
+assert.sameValue(Number("0xE_E"), 0xEE);
+assert.sameValue(Number("0xF_F"), 0xFF);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-nzd-nsl-dd-one-of.js b/test/built-ins/Number/string-numeric-separator-literal-nzd-nsl-dd-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..eec4e828c10da47d7c3396ef1a59da9fc5fdf6a6
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-nzd-nsl-dd-one-of.js
@@ -0,0 +1,38 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: NonZeroDigit NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+ NonZeroDigit :: one of
+ 1 2 3 4 5 6 7 8 9
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+
+ DecimalDigit :: one of
+ 0 1 2 3 4 5 6 7 8 9
+
+---*/
+
+assert.sameValue(Number("1_0"), 10);
+assert.sameValue(Number("1_1"), 11);
+assert.sameValue(Number("2_2"), 22);
+assert.sameValue(Number("3_3"), 33);
+assert.sameValue(Number("4_4"), 44);
+assert.sameValue(Number("5_5"), 55);
+assert.sameValue(Number("6_6"), 66);
+assert.sameValue(Number("7_7"), 77);
+assert.sameValue(Number("8_8"), 88);
+assert.sameValue(Number("9_9"), 99);
+
+
diff --git a/test/built-ins/Number/string-numeric-separator-literal-nzd-nsl-dd.js b/test/built-ins/Number/string-numeric-separator-literal-nzd-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..7ec57ad614de282b35ad472b0a53df2af6cec0e5
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-nzd-nsl-dd.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: NonZeroDigit NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+ NonZeroDigit :: one of
+ 1 2 3 4 5 6 7 8 9
+
+ DecimalDigits ::
+ ...
+ DecimalDigits DecimalDigit
+ ...
+
+---*/
+
+assert.sameValue(Number("1_1"), 11);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-nzd-nsl-dds.js b/test/built-ins/Number/string-numeric-separator-literal-nzd-nsl-dds.js
new file mode 100644
index 0000000000000000000000000000000000000000..7410a68f87676bffd62805cc8f6398cd2288de6a
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-nzd-nsl-dds.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: NonZeroDigit NumericLiteralSeparator DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+ NonZeroDigit :: one of
+ 1 2 3 4 5 6 7 8 9
+
+ DecimalDigits ::
+ ...
+ DecimalDigits DecimalDigit
+ ...
+
+---*/
+
+assert.sameValue(Number("1_0123456789"), 10123456789);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-oil-od-nsl-od-one-of.js b/test/built-ins/Number/string-numeric-separator-literal-oil-od-nsl-od-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..ceec7a92c03160aa982cbeaed376e8948ec0778b
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-oil-od-nsl-od-one-of.js
@@ -0,0 +1,33 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0o` | `0O` OctalDigit NumericLiteralSeparator OctalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+---*/
+
+assert.sameValue(Number("0o0_0"), 0o00);
+assert.sameValue(Number("0o1_1"), 0o11);
+assert.sameValue(Number("0o2_2"), 0o22);
+assert.sameValue(Number("0o3_3"), 0o33);
+assert.sameValue(Number("0o4_4"), 0o44);
+assert.sameValue(Number("0o5_5"), 0o55);
+assert.sameValue(Number("0o6_6"), 0o66);
+assert.sameValue(Number("0o7_7"), 0o77);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-oil-od-nsl-od.js b/test/built-ins/Number/string-numeric-separator-literal-oil-od-nsl-od.js
new file mode 100644
index 0000000000000000000000000000000000000000..aa4dedf3b5a79867c91f46cb1f8cb14bae747b1a
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-oil-od-nsl-od.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0o` | `0O` OctalDigit NumericLiteralSeparator OctalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+---*/
+
+assert.sameValue(Number("0o0_1"), 0o01);
+assert.sameValue(Number("0O0_1"), 0O01);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-oil-od-nsl-ods.js b/test/built-ins/Number/string-numeric-separator-literal-oil-od-nsl-ods.js
new file mode 100644
index 0000000000000000000000000000000000000000..44ffef8015c60990f263d938f479e03522ce6195
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-oil-od-nsl-ods.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0o` | `0O` OctalDigit NumericLiteralSeparator OctalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+---*/
+
+assert.sameValue(Number("0o0_10"), 0o010);
+assert.sameValue(Number("0O0_10"), 0O010);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-oil-ods-nsl-od.js b/test/built-ins/Number/string-numeric-separator-literal-oil-ods-nsl-od.js
new file mode 100644
index 0000000000000000000000000000000000000000..ee2e0aa2a875dcd0cb4db30d9ededaaf657ac387
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-oil-ods-nsl-od.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0o` | `0O` OctalDigits NumericLiteralSeparator OctalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+---*/
+
+assert.sameValue(Number("0o01_0"), 0o010);
+assert.sameValue(Number("0O01_0"), 0O010);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-oil-ods-nsl-ods.js b/test/built-ins/Number/string-numeric-separator-literal-oil-ods-nsl-ods.js
new file mode 100644
index 0000000000000000000000000000000000000000..77c6e414cf33a259f7b92f0c03d8415ee4c58fbb
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-oil-ods-nsl-ods.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0o` | `0O` OctalDigits NumericLiteralSeparator OctalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+---*/
+
+assert.sameValue(Number("0o01_00"), 0o0100);
+assert.sameValue(Number("0O01_00"), 0O0100);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-sign-minus-dds-nsl-dd.js b/test/built-ins/Number/string-numeric-separator-literal-sign-minus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..060a03416aa2af3fbf6338bd8b9555b04f5050f2
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-sign-minus-dds-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: DecimalDigits NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ SignedInteger ::
+ ...
+ - DecimalDigits
+
+---*/
+
+assert.sameValue(Number("-123456789_0"), -1234567890);
+assert.sameValue(Number("-123456789_1"), -1234567891);
+assert.sameValue(Number("-123456789_2"), -1234567892);
+assert.sameValue(Number("-123456789_3"), -1234567893);
+assert.sameValue(Number("-123456789_4"), -1234567894);
+assert.sameValue(Number("-123456789_5"), -1234567895);
+assert.sameValue(Number("-123456789_6"), -1234567896);
+assert.sameValue(Number("-123456789_7"), -1234567897);
+assert.sameValue(Number("-123456789_8"), -1234567898);
+assert.sameValue(Number("-123456789_9"), -1234567899);
diff --git a/test/built-ins/Number/string-numeric-separator-literal-sign-plus-dds-nsl-dd.js b/test/built-ins/Number/string-numeric-separator-literal-sign-plus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..813faf91d146a73625fe469eab8fceef8da3529d
--- /dev/null
+++ b/test/built-ins/Number/string-numeric-separator-literal-sign-plus-dds-nsl-dd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: DecimalDigits NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ SignedInteger ::
+ ...
+ + DecimalDigits
+ ...
+
+---*/
+
+assert.sameValue(Number("+123456789_0"), 1234567890);
+assert.sameValue(Number("+123456789_1"), 1234567891);
+assert.sameValue(Number("+123456789_2"), 1234567892);
+assert.sameValue(Number("+123456789_3"), 1234567893);
+assert.sameValue(Number("+123456789_4"), 1234567894);
+assert.sameValue(Number("+123456789_5"), 1234567895);
+assert.sameValue(Number("+123456789_6"), 1234567896);
+assert.sameValue(Number("+123456789_7"), 1234567897);
+assert.sameValue(Number("+123456789_8"), 1234567898);
+assert.sameValue(Number("+123456789_9"), 1234567899);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bd-nsl-bd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bd-nsl-bd.js
new file mode 100644
index 0000000000000000000000000000000000000000..2f994aa3e527f232fcff9e263b7b121729108ab6
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bd-nsl-bd.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0b StrBinaryDigits, 0B StrBinaryDigits
+info: |
+
+ StrBinaryIntegerLiteral :::
+ 0b StrBinaryDigits
+ 0B StrBinaryDigits
+
+ StrBinaryDigits :::
+ BinaryDigit
+ StrBinaryDigits BinaryDigit
+
+ BinaryDigit ::: one of
+ 0 1
+
+---*/
+
+assert.sameValue(parseFloat("0b0_1"), 0b0);
+assert.sameValue(parseFloat("0B0_1"), 0B0);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bd-nsl-bds.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bd-nsl-bds.js
new file mode 100644
index 0000000000000000000000000000000000000000..d5164500b73729fb8a3c6701e399cb625e92f611
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bd-nsl-bds.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0b StrBinaryDigits, 0B StrBinaryDigits
+info: |
+
+ StrBinaryIntegerLiteral :::
+ 0b StrBinaryDigits
+ 0B StrBinaryDigits
+
+ StrBinaryDigits :::
+ BinaryDigit
+ StrBinaryDigits BinaryDigit
+
+ BinaryDigit ::: one of
+ 0 1
+
+---*/
+
+assert.sameValue(parseFloat("0b0_10"), 0b0);
+assert.sameValue(parseFloat("0B0_10"), 0B0);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bds-nsl-bd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bds-nsl-bd.js
new file mode 100644
index 0000000000000000000000000000000000000000..dc4207be9d74b8ca2dc3ffad87ef3bfe861ad143
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bds-nsl-bd.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0b StrBinaryDigits, 0B StrBinaryDigits
+info: |
+
+ StrBinaryIntegerLiteral :::
+ 0b StrBinaryDigits
+ 0B StrBinaryDigits
+
+ StrBinaryDigits :::
+ BinaryDigit
+ StrBinaryDigits BinaryDigit
+
+ BinaryDigit ::: one of
+ 0 1
+
+---*/
+
+assert.sameValue(parseFloat("0b01_0"), 0b01);
+assert.sameValue(parseFloat("0B01_0"), 0B01);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bds-nsl-bds.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bds-nsl-bds.js
new file mode 100644
index 0000000000000000000000000000000000000000..daa545afb9883a6c62f7e74870a2c4f7944bd783
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-bil-bds-nsl-bds.js
@@ -0,0 +1,23 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0b StrBinaryDigits, 0B StrBinaryDigits
+info: |
+
+ StrBinaryIntegerLiteral :::
+ 0b StrBinaryDigits
+ 0B StrBinaryDigits
+
+ StrBinaryDigits :::
+ BinaryDigit
+ StrBinaryDigits BinaryDigit
+
+ BinaryDigit ::: one of
+ 0 1
+
+---*/
+
+assert.sameValue(parseFloat("0b01_00"), 0b01);
+assert.sameValue(parseFloat("0B01_00"), 0B01);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dd-nsl-dd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dd-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..8463acc6e8cb733f8761a65177c9838426f46ded
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dd-nsl-dd.js
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: StrDecimalDigits . StrDecimalDigits StrExponentPart
+info: |
+
+ StrUnsignedDecimalLiteral :::
+ StrDecimalDigits . StrDecimalDigits StrExponentPart
+
+ StrDecimalDigits :::
+ DecimalDigit
+ StrDecimalDigits NumericLiteralSeparator DecimalDigit
+
+
+---*/
+
+assert.sameValue(parseFloat("1.0e-1_0"), 1.0e-1);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dds-nsl-dd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..31afc26b42c6753fe8a478bc42821c21249a63fa
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-minus-dds-nsl-dd.js
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: StrDecimalDigits . StrDecimalDigits StrExponentPart
+info: |
+
+ StrUnsignedDecimalLiteral :::
+ StrDecimalDigits . StrDecimalDigits StrExponentPart
+
+ StrDecimalDigits :::
+ DecimalDigit
+ StrDecimalDigits NumericLiteralSeparator DecimalDigit
+
+
+---*/
+
+assert.sameValue(parseFloat("1.0e-10_0"), 1.0e-10);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dd-nsl-dd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dd-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..4331a370d327c421100568ff1df7ebd73201f310
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dd-nsl-dd.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: >
+ StrDecimalDigits . StrDecimalDigits StrExponentPart
+info: |
+
+ StrUnsignedDecimalLiteral :::
+ StrDecimalDigits . StrDecimalDigits StrExponentPart
+
+ StrDecimalDigits :::
+ DecimalDigit
+ StrDecimalDigits NumericLiteralSeparator DecimalDigit
+
+
+---*/
+
+assert.sameValue(parseFloat("1.0e+1_0"), 1.0e+1);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dds-nsl-dd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..f68cc93c8ebc21269c041b47aab459f49db418a3
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-dot-dd-ep-sign-plus-dds-nsl-dd.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: StrDecimalDigits . StrDecimalDigits StrExponentPart
+info: |
+
+ StrUnsignedDecimalLiteral :::
+ StrDecimalDigits . StrDecimalDigits StrExponentPart
+
+ StrDecimalDigits :::
+ DecimalDigit
+ StrDecimalDigits NumericLiteralSeparator DecimalDigit
+
+
+---*/
+
+assert.sameValue(parseFloat("1.0e+10_0"), 1.0e+10);
+
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-nsl-dd-one-of.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-nsl-dd-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..fb0ba7236c2074bc9246e765b30edc1bcbd0cbf0
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dd-nsl-dd-one-of.js
@@ -0,0 +1,31 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: StrUnsignedDecimalLiteral
+info: |
+
+ StrStrUnsignedDecimalLiteral :::
+ StrUnsignedDecimalLiteral
+
+
+ StrDecimalDigits :::
+ DecimalDigit
+ ...
+
+ DecimalDigit ::: one of
+ 0 1 2 3 4 5 6 7 8 9
+
+---*/
+
+assert.sameValue(parseFloat("1_0"), 1);
+assert.sameValue(parseFloat("1_1"), 1);
+assert.sameValue(parseFloat("1_2"), 1);
+assert.sameValue(parseFloat("1_3"), 1);
+assert.sameValue(parseFloat("1_4"), 1);
+assert.sameValue(parseFloat("1_5"), 1);
+assert.sameValue(parseFloat("1_6"), 1);
+assert.sameValue(parseFloat("1_7"), 1);
+assert.sameValue(parseFloat("1_8"), 1);
+assert.sameValue(parseFloat("1_9"), 1);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dds-dot-dd-nsl-dd-ep-dd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dds-dot-dd-nsl-dd-ep-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..b90c3b22c65e5dd1c5e451950f905eacf7dc3909
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dds-dot-dd-nsl-dd-ep-dd.js
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: StrDecimalDigits . StrDecimalDigits StrExponentPart
+info: |
+
+ StrUnsignedDecimalLiteral :::
+ . StrDecimalDigits StrExponentPart
+
+ StrDecimalDigits :::
+ DecimalDigit
+ StrDecimalDigits DecimalDigit
+
+---*/
+
+assert.sameValue(parseFloat("10.00_01e2"), 10.00);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dds-nsl-dd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..b4d6094eb08a8bef573e0bc14a623e3248d22673
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dds-nsl-dd.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: StrDecimalDigits
+info: |
+
+ StrDecimalDigits :::
+ DecimalDigit
+ StrDecimalDigits DecimalDigit
+
+---*/
+
+assert.sameValue(parseFloat("123456789_0"), 123456789);
+assert.sameValue(parseFloat("123456789_1"), 123456789);
+assert.sameValue(parseFloat("123456789_2"), 123456789);
+assert.sameValue(parseFloat("123456789_3"), 123456789);
+assert.sameValue(parseFloat("123456789_4"), 123456789);
+assert.sameValue(parseFloat("123456789_5"), 123456789);
+assert.sameValue(parseFloat("123456789_6"), 123456789);
+assert.sameValue(parseFloat("123456789_7"), 123456789);
+assert.sameValue(parseFloat("123456789_8"), 123456789);
+assert.sameValue(parseFloat("123456789_9"), 123456789);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dd-nsl-dd-ep.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dd-nsl-dd-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..721a679019358a7060b930e33d99494f42eb63ec
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dd-nsl-dd-ep.js
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: . StrDecimalDigits StrExponentPart
+info: |
+
+ StrUnsignedDecimalLiteral :::
+ . StrDecimalDigits StrExponentPart
+
+ StrDecimalDigits :::
+ DecimalDigit
+ ...
+ StrDecimalDigits DecimalDigit
+
+---*/
+
+assert.sameValue(parseFloat(".0_1e2"), .0);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dd-nsl-dds-ep.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dd-nsl-dds-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..1f3dc3b30e0056d221f0f9b0692135c6e185eec2
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dd-nsl-dds-ep.js
@@ -0,0 +1,19 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: . StrDecimalDigits StrExponentPart
+info: |
+
+ StrUnsignedDecimalLiteral :::
+ . StrDecimalDigits StrExponentPart
+
+ StrDecimalDigits :::
+ DecimalDigit
+ ...
+ StrDecimalDigits DecimalDigit
+
+---*/
+
+assert.sameValue(parseFloat(".1_01e2"), .1);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dds-nsl-dd-ep.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dds-nsl-dd-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..278dbe682969b7c71e5a7b3f09b09027d2b39dee
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dds-nsl-dd-ep.js
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: . StrDecimalDigits StrExponentPart
+info: |
+
+ StrUnsignedDecimalLiteral :::
+ . StrDecimalDigits StrExponentPart
+
+ StrDecimalDigits :::
+ DecimalDigit
+ StrDecimalDigits DecimalDigit
+
+---*/
+
+assert.sameValue(parseFloat(".10_1e2"), .10);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dds-nsl-dds-ep.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dds-nsl-dds-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..da0490ddd5172a53c270c66b27630043a40a28b6
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-dot-dds-nsl-dds-ep.js
@@ -0,0 +1,18 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: . StrDecimalDigits StrExponentPart
+info: |
+
+ StrUnsignedDecimalLiteral :::
+ . StrDecimalDigits StrExponentPart
+
+ StrDecimalDigits :::
+ DecimalDigit
+ StrDecimalDigits DecimalDigit
+
+---*/
+
+assert.sameValue(parseFloat(".00_01e2"), .00);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hd-nsl-hd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hd-nsl-hd.js
new file mode 100644
index 0000000000000000000000000000000000000000..59330a2f4ca4487820ca124ea0d7fe6ca1dc150f
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hd-nsl-hd.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0x StrHexDigits, 0X StrHexDigits
+info: |
+
+ StrHexLiteral :::
+ 0x StrHexDigits
+ 0X StrHexDigits
+
+ StrHexDigits :::
+ HexDigit
+ StrHexDigits HexDigit
+
+---*/
+
+assert.sameValue(parseFloat("0x0_1"), 0x0);
+assert.sameValue(parseFloat("0X0_1"), 0X0);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hd-nsl-hds.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hd-nsl-hds.js
new file mode 100644
index 0000000000000000000000000000000000000000..06f3a44c62d17f5024f745ab796c232eb98a9f0a
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hd-nsl-hds.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0x StrHexDigits, 0X StrHexDigits
+info: |
+
+ StrHexLiteral :::
+ 0x StrHexDigits
+ 0X StrHexDigits
+
+ StrHexDigits :::
+ HexDigit
+ StrHexDigits HexDigit
+
+---*/
+
+assert.sameValue(parseFloat("0x0_10"), 0x0);
+assert.sameValue(parseFloat("0X0_10"), 0X0);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hds-nsl-hd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hds-nsl-hd.js
new file mode 100644
index 0000000000000000000000000000000000000000..e4bc5b9fd801c229a26c9f0f8a7735c8d0ad7114
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hds-nsl-hd.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0x StrHexDigits, 0X StrHexDigits
+info: |
+
+ StrHexLiteral :::
+ 0x StrHexDigits
+ 0X StrHexDigits
+
+ StrHexDigits :::
+ HexDigit
+ StrHexDigits HexDigit
+
+---*/
+
+assert.sameValue(parseFloat("0x01_0"), 0x01);
+assert.sameValue(parseFloat("0X01_0"), 0X01);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hds-nsl-hds.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hds-nsl-hds.js
new file mode 100644
index 0000000000000000000000000000000000000000..4cbdf527a3a5033608439d1012d1f6cb666beef0
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-hds-nsl-hds.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0x StrHexDigits, 0X StrHexDigits
+info: |
+
+ StrHexLiteral :::
+ 0x StrHexDigits
+ 0X StrHexDigits
+
+ StrHexDigits :::
+ HexDigit
+ StrHexDigits HexDigit
+
+---*/
+
+assert.sameValue(parseFloat("0x01_00"), 0x01);
+assert.sameValue(parseFloat("0X01_00"), 0X01);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-od-nsl-od-one-of.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-od-nsl-od-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..c28f00087d965a757288a76ef30af075dd2668b1
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-hil-od-nsl-od-one-of.js
@@ -0,0 +1,40 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0x StrHexDigits, 0X StrHexDigits
+info: |
+
+ StrHexLiteral :::
+ 0x StrHexDigits
+ 0X StrHexDigits
+
+ StrHexDigits :::
+ HexDigit
+ StrHexDigits HexDigit
+
+---*/
+
+assert.sameValue(parseFloat("0x0_0"), 0x0);
+assert.sameValue(parseFloat("0x1_1"), 0x1);
+assert.sameValue(parseFloat("0x2_2"), 0x2);
+assert.sameValue(parseFloat("0x3_3"), 0x3);
+assert.sameValue(parseFloat("0x4_4"), 0x4);
+assert.sameValue(parseFloat("0x5_5"), 0x5);
+assert.sameValue(parseFloat("0x6_6"), 0x6);
+assert.sameValue(parseFloat("0x7_7"), 0x7);
+assert.sameValue(parseFloat("0x8_8"), 0x8);
+assert.sameValue(parseFloat("0x9_9"), 0x9);
+assert.sameValue(parseFloat("0xa_a"), 0xa);
+assert.sameValue(parseFloat("0xb_b"), 0xb);
+assert.sameValue(parseFloat("0xc_c"), 0xc);
+assert.sameValue(parseFloat("0xd_d"), 0xd);
+assert.sameValue(parseFloat("0xe_e"), 0xe);
+assert.sameValue(parseFloat("0xf_f"), 0xf);
+assert.sameValue(parseFloat("0xA_A"), 0xA);
+assert.sameValue(parseFloat("0xB_B"), 0xB);
+assert.sameValue(parseFloat("0xC_C"), 0xC);
+assert.sameValue(parseFloat("0xD_D"), 0xD);
+assert.sameValue(parseFloat("0xE_E"), 0xE);
+assert.sameValue(parseFloat("0xF_F"), 0xF);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-nzd-nsl-dd-one-of.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-nzd-nsl-dd-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..932a83451b7d23b8fc12f7b3efc7e255e75d5f50
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-nzd-nsl-dd-one-of.js
@@ -0,0 +1,33 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: NonZeroDigit NumericLiteralSeparator DecimalDigit
+info: |
+
+ StrStrUnsignedDecimalLiteral :::
+ StrUnsignedDecimalLiteral
+
+ NonZeroDigit ::: one of
+ 1 2 3 4 5 6 7 8 9
+
+ StrDecimalDigits :::
+ DecimalDigit
+ ...
+
+ DecimalDigit ::: one of
+ 0 1 2 3 4 5 6 7 8 9
+
+---*/
+
+assert.sameValue(parseFloat("1_0"), 1);
+assert.sameValue(parseFloat("1_1"), 1);
+assert.sameValue(parseFloat("2_2"), 2);
+assert.sameValue(parseFloat("3_3"), 3);
+assert.sameValue(parseFloat("4_4"), 4);
+assert.sameValue(parseFloat("5_5"), 5);
+assert.sameValue(parseFloat("6_6"), 6);
+assert.sameValue(parseFloat("7_7"), 7);
+assert.sameValue(parseFloat("8_8"), 8);
+assert.sameValue(parseFloat("9_9"), 9);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-nzd-nsl-dd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-nzd-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..4f454d5953db207b939ac6b4a457a65add7b971f
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-nzd-nsl-dd.js
@@ -0,0 +1,16 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: StrDecimalDigits
+info: |
+
+ StrDecimalDigits :::
+ DecimalDigit
+ StrDecimalDigits DecimalDigit
+ ...
+
+---*/
+
+assert.sameValue(parseFloat("1_1"), 1);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-nzd-nsl-dds.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-nzd-nsl-dds.js
new file mode 100644
index 0000000000000000000000000000000000000000..e182b0a3c6a45ab4db5c06fe1d3d45910c2ba0ef
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-nzd-nsl-dds.js
@@ -0,0 +1,15 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: DecimalDigit
+info: |
+
+ StrDecimalDigits :::
+ DecimalDigit
+ StrDecimalDigits DecimalDigit
+
+---*/
+
+assert.sameValue(parseFloat("1_0123456789"), 1);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-od-nsl-od-one-of.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-od-nsl-od-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..fd9e178d9fd8276991413d29cddbfe84d67245bf
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-od-nsl-od-one-of.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0o StrOctalDigits, 0O StrOctalDigits
+info: |
+
+ StrOctalLiteral :::
+ 0o StrOctalDigits
+ 0O StrOctalDigits
+
+ StrOctalDigits :::
+ OctalDigit
+ StrOctalDigits OctalDigit
+
+---*/
+
+assert.sameValue(parseFloat("0o0_0"), 0o0);
+assert.sameValue(parseFloat("0o1_1"), 0o1);
+assert.sameValue(parseFloat("0o2_2"), 0o2);
+assert.sameValue(parseFloat("0o3_3"), 0o3);
+assert.sameValue(parseFloat("0o4_4"), 0o4);
+assert.sameValue(parseFloat("0o5_5"), 0o5);
+assert.sameValue(parseFloat("0o6_6"), 0o6);
+assert.sameValue(parseFloat("0o7_7"), 0o7);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-od-nsl-od.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-od-nsl-od.js
new file mode 100644
index 0000000000000000000000000000000000000000..0721ea9856c2f8f88a5c299870edf6c7466431e5
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-od-nsl-od.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0o StrOctalDigits, 0O StrOctalDigits
+info: |
+
+ StrOctalLiteral :::
+ 0o StrOctalDigits
+ 0O StrOctalDigits
+
+ StrOctalDigits :::
+ OctalDigit
+ StrOctalDigits OctalDigit
+
+---*/
+
+assert.sameValue(parseFloat("0o0_1"), 0o0);
+assert.sameValue(parseFloat("0O0_1"), 0O0);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-od-nsl-ods.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-od-nsl-ods.js
new file mode 100644
index 0000000000000000000000000000000000000000..174e45325cea493380312fa81bf3b4907f7881f8
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-od-nsl-ods.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0o StrOctalDigits, 0O StrOctalDigits
+info: |
+
+ StrOctalLiteral :::
+ 0o StrOctalDigits
+ 0O StrOctalDigits
+
+ StrOctalDigits :::
+ OctalDigit
+ StrOctalDigits OctalDigit
+
+---*/
+
+assert.sameValue(parseFloat("0o0_10"), 0o0);
+assert.sameValue(parseFloat("0O0_10"), 0O0);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-ods-nsl-od.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-ods-nsl-od.js
new file mode 100644
index 0000000000000000000000000000000000000000..6f328e3dd10558412d7bc5d5fb106ccb08c4d04c
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-ods-nsl-od.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0o StrOctalDigits, 0O StrOctalDigits
+info: |
+
+ StrOctalLiteral :::
+ 0o StrOctalDigits
+ 0O StrOctalDigits
+
+ StrOctalDigits :::
+ OctalDigit
+ StrOctalDigits OctalDigit
+
+---*/
+
+assert.sameValue(parseFloat("0o01_0"), 0o01);
+assert.sameValue(parseFloat("0O01_0"), 0O01);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-ods-nsl-ods.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-ods-nsl-ods.js
new file mode 100644
index 0000000000000000000000000000000000000000..4ccd61f3789808f6ce6baf8ea8117c6c6b958d7f
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-oil-ods-nsl-ods.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: 0o StrOctalDigits, 0O StrOctalDigits
+info: |
+
+ StrOctalLiteral :::
+ 0o StrOctalDigits
+ 0O StrOctalDigits
+
+ StrOctalDigits :::
+ OctalDigit
+ StrOctalDigits OctalDigit
+
+---*/
+
+assert.sameValue(parseFloat("0o01_00"), 0o01);
+assert.sameValue(parseFloat("0O01_00"), 0O01);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-sign-minus-dds-nsl-dd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-sign-minus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..a0917f913e4e06bc1bf865dd96f39e718521fcbe
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-sign-minus-dds-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: >
+ StrUnsignedDecimalLiteral, + StrUnsignedDecimalLiteral, - StrUnsignedDecimalLiteral
+info: |
+
+ StrDecimalLiteral :::
+ StrUnsignedDecimalLiteral
+ + StrUnsignedDecimalLiteral
+ - StrUnsignedDecimalLiteral
+
+---*/
+
+assert.sameValue(parseFloat("-123456789_0"), -123456789);
+assert.sameValue(parseFloat("-123456789_1"), -123456789);
+assert.sameValue(parseFloat("-123456789_2"), -123456789);
+assert.sameValue(parseFloat("-123456789_3"), -123456789);
+assert.sameValue(parseFloat("-123456789_4"), -123456789);
+assert.sameValue(parseFloat("-123456789_5"), -123456789);
+assert.sameValue(parseFloat("-123456789_6"), -123456789);
+assert.sameValue(parseFloat("-123456789_7"), -123456789);
+assert.sameValue(parseFloat("-123456789_8"), -123456789);
+assert.sameValue(parseFloat("-123456789_9"), -123456789);
diff --git a/test/built-ins/parseFloat/tonumber-numeric-separator-literal-sign-plus-dds-nsl-dd.js b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-sign-plus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..224a0e4e3e42bc2201e5c6a41b762ff8f9173db4
--- /dev/null
+++ b/test/built-ins/parseFloat/tonumber-numeric-separator-literal-sign-plus-dds-nsl-dd.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-tonumber-applied-to-the-string-type
+description: StrUnsignedDecimalLiteral
+info: |
+
+ StrDecimalLiteral :::
+ StrUnsignedDecimalLiteral
+ + StrUnsignedDecimalLiteral
+ - StrUnsignedDecimalLiteral
+
+---*/
+
+assert.sameValue(parseFloat("+123456789_0"), +123456789);
+assert.sameValue(parseFloat("+123456789_1"), +123456789);
+assert.sameValue(parseFloat("+123456789_2"), +123456789);
+assert.sameValue(parseFloat("+123456789_3"), +123456789);
+assert.sameValue(parseFloat("+123456789_4"), +123456789);
+assert.sameValue(parseFloat("+123456789_5"), +123456789);
+assert.sameValue(parseFloat("+123456789_6"), +123456789);
+assert.sameValue(parseFloat("+123456789_7"), +123456789);
+assert.sameValue(parseFloat("+123456789_8"), +123456789);
+assert.sameValue(parseFloat("+123456789_9"), +123456789);
diff --git a/test/language/literals/numeric/numeric-separator-literal-bil-bd-nsl-bd-err.js b/test/language/literals/numeric/numeric-separator-literal-bil-bd-nsl-bd-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..44a9cb1ee857f33f30f6768a65eb099f9f8f84ab
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-bil-bd-nsl-bd-err.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not be the appear adjacent to `0b` | `0B` in a
+ BinaryIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0b_1
diff --git a/test/language/literals/numeric/numeric-separator-literal-bil-bd-nsl-bd.js b/test/language/literals/numeric/numeric-separator-literal-bil-bd-nsl-bd.js
new file mode 100644
index 0000000000000000000000000000000000000000..f9d5d3cf02099f2009b0f24cef53aa18521f1349
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-bil-bd-nsl-bd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0b` | `0B` BinaryDigit NumericLiteralSeparator BinaryDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+---*/
+
+assert.sameValue(0b0_1, 0b01);
+assert.sameValue(0B0_1, 0B01);
diff --git a/test/language/literals/numeric/numeric-separator-literal-bil-bd-nsl-bds.js b/test/language/literals/numeric/numeric-separator-literal-bil-bd-nsl-bds.js
new file mode 100644
index 0000000000000000000000000000000000000000..26b19114f78e913cb1ff945ed261074540f18092
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-bil-bd-nsl-bds.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0b` | `0B` BinaryDigit NumericLiteralSeparator BinaryDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+---*/
+
+assert.sameValue(0b0_10, 0b010);
+assert.sameValue(0B0_10, 0B010);
diff --git a/test/language/literals/numeric/numeric-separator-literal-bil-bds-nsl-bd.js b/test/language/literals/numeric/numeric-separator-literal-bil-bds-nsl-bd.js
new file mode 100644
index 0000000000000000000000000000000000000000..323259549b15035fec582030731c2c9d1bad8111
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-bil-bds-nsl-bd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0b` | `0B` BinaryDigits NumericLiteralSeparator BinaryDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+---*/
+
+assert.sameValue(0b01_0, 0b010);
+assert.sameValue(0B01_0, 0B010);
diff --git a/test/language/literals/numeric/numeric-separator-literal-bil-bds-nsl-bds.js b/test/language/literals/numeric/numeric-separator-literal-bil-bds-nsl-bds.js
new file mode 100644
index 0000000000000000000000000000000000000000..744913f05c61ca0ae6ce95d2ca63c1a4772e3439
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-bil-bds-nsl-bds.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0b` | `0B` BinaryDigits NumericLiteralSeparator BinaryDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+---*/
+
+assert.sameValue(0b01_00, 0b0100);
+assert.sameValue(0B01_00, 0B0100);
diff --git a/test/language/literals/numeric/numeric-separator-literal-bil-nsl-bd-dunder-err.js b/test/language/literals/numeric/numeric-separator-literal-bil-nsl-bd-dunder-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..3cadb7a8116c621a850b4259590097a5d4534b3c
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-bil-nsl-bd-dunder-err.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not appear adjacent to another
+ NumericLiteralSeparator in a BinaryIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0b0__0
diff --git a/test/language/literals/numeric/numeric-separator-literal-bil-nsl-bd-err.js b/test/language/literals/numeric/numeric-separator-literal-bil-nsl-bd-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..51ac17e97a18bd681fe6bbc9398762c4389a9539
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-bil-nsl-bd-err.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not be the last digit character of a
+ BinaryIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ BinaryIntegerLiteral ::
+ 0b BinaryDigits
+ 0B BinaryDigits
+
+ BinaryDigits ::
+ BinaryDigit
+ BinaryDigits BinaryDigit
+ BinaryDigits NumericLiteralSeparator BinaryDigit
+
+ BinaryDigit :: one of
+ 0 1
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0b0_
diff --git a/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-minus-dd-nsl-dd.js b/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-minus-dd-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..f7bca1ee7b08ef752004eda258b1e28660b597f9
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-minus-dd-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ DecimalDigits `.` DecimalDigits ExponentPart_opt `-` DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ SignedInteger ::
+ ...
+ - DecimalDigits
+ ...
+
+---*/
+
+assert.sameValue(1.0e-1_0, 1.0e-10);
diff --git a/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-minus-dds-nsl-dd.js b/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-minus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..9057143c62d57ffa01dff527aad2c95e9ec96411
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-minus-dds-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ DecimalDigits `.` DecimalDigits ExponentPart_opt `-` DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ SignedInteger ::
+ ...
+ - DecimalDigits
+ ...
+
+---*/
+
+assert.sameValue(1.0e-10_0, 1.0e-100);
diff --git a/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-plus-dd-nsl-dd.js b/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-plus-dd-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..ac5b67c2b7d3b02129fe946e07cae57ef302c328
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-plus-dd-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ DecimalDigits `.` DecimalDigits ExponentPart_opt `+` DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ SignedInteger ::
+ ...
+ + DecimalDigits
+ ...
+
+---*/
+
+assert.sameValue(1.0e+1_0, 1.0e+10);
diff --git a/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-plus-dds-nsl-dd.js b/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-plus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..eeeb5f957eb707fb296acacdef6feb6640f21071
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dd-dot-dd-ep-sign-plus-dds-nsl-dd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ DecimalDigits `.` DecimalDigits ExponentPart_opt `+` DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ SignedInteger ::
+ ...
+ + DecimalDigits
+ ...
+
+---*/
+
+assert.sameValue(1.0e+10_0, 1.0e+100);
+
diff --git a/test/language/literals/numeric/numeric-separator-literal-dd-nsl-dd-one-of.js b/test/language/literals/numeric/numeric-separator-literal-dd-nsl-dd-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..79f5b5ada08c17af9b1a3843bff2e512be40e939
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dd-nsl-dd-one-of.js
@@ -0,0 +1,34 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: NonZeroDigit NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+
+ DecimalDigit :: one of
+ 0 1 2 3 4 5 6 7 8 9
+
+---*/
+
+assert.sameValue(1_0, 10);
+assert.sameValue(1_1, 11);
+assert.sameValue(1_2, 12);
+assert.sameValue(1_3, 13);
+assert.sameValue(1_4, 14);
+assert.sameValue(1_5, 15);
+assert.sameValue(1_6, 16);
+assert.sameValue(1_7, 17);
+assert.sameValue(1_8, 18);
+assert.sameValue(1_9, 19);
diff --git a/test/language/literals/numeric/numeric-separator-literal-dd-nsl-dds-dunder-err.js b/test/language/literals/numeric/numeric-separator-literal-dd-nsl-dds-dunder-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..800714be2c097cf64db3052672b99759aa578f2f
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dd-nsl-dds-dunder-err.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not appear adjacent to another
+ NumericLiteralSeparator in a DecimalIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+1__0123456789
diff --git a/test/language/literals/numeric/numeric-separator-literal-dd-nsl-err.js b/test/language/literals/numeric/numeric-separator-literal-dd-nsl-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..11b89ce2c67b012fe1d05094b255a69d0a655ec0
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dd-nsl-err.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not be the last digit character
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+1_
diff --git a/test/language/literals/numeric/numeric-separator-literal-dds-dot-dd-nsl-dd-ep-dd.js b/test/language/literals/numeric/numeric-separator-literal-dds-dot-dd-nsl-dd-ep-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..a3f78d5060e086b84ab5159125acd3678f05d640
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dds-dot-dd-nsl-dd-ep-dd.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ DecimalDigits `.` DecimalDigits NumericLiteralSeparator DecimalDigits
+ ExponentPart SignedInteger
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+---*/
+
+assert.sameValue(10.00_01e2, 10.0001e2);
diff --git a/test/language/literals/numeric/numeric-separator-literal-dds-nsl-dd.js b/test/language/literals/numeric/numeric-separator-literal-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..3ca1dee1e3d391effcd3585be704e3b81baf2541
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dds-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: DecimalDigits NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+---*/
+
+assert.sameValue(123456789_0, 1234567890);
+assert.sameValue(123456789_1, 1234567891);
+assert.sameValue(123456789_2, 1234567892);
+assert.sameValue(123456789_3, 1234567893);
+assert.sameValue(123456789_4, 1234567894);
+assert.sameValue(123456789_5, 1234567895);
+assert.sameValue(123456789_6, 1234567896);
+assert.sameValue(123456789_7, 1234567897);
+assert.sameValue(123456789_8, 1234567898);
+assert.sameValue(123456789_9, 1234567899);
diff --git a/test/language/literals/numeric/numeric-separator-literal-dds-nsl-dds-dunder-err.js b/test/language/literals/numeric/numeric-separator-literal-dds-nsl-dds-dunder-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..560fe23576b2ba4ecf3ad420100ed7e7973d2c35
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dds-nsl-dds-dunder-err.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not appear adjacent to another
+ NumericLiteralSeparator in DecimalIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+10__0123456789
diff --git a/test/language/literals/numeric/numeric-separator-literal-dds-nsl-err.js b/test/language/literals/numeric/numeric-separator-literal-dds-nsl-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..a72b521e73a9d0047b2d7bf1b8932cc441ae4ffd
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dds-nsl-err.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not be the last digit character of a
+ DecimalLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+10_
diff --git a/test/language/literals/numeric/numeric-separator-literal-dil-dot-dds-nsl-ep-dd-err.js b/test/language/literals/numeric/numeric-separator-literal-dil-dot-dds-nsl-ep-dd-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..ce96ca079b2d2e1ab8e6c7b9527241984b8be4dc
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dil-dot-dds-nsl-ep-dd-err.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not appear adjacent to ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+10.0_e1
diff --git a/test/language/literals/numeric/numeric-separator-literal-dil-dot-nsl-ep-err.js b/test/language/literals/numeric/numeric-separator-literal-dil-dot-nsl-ep-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..9b2c418bef459e467372b6de5d8db09c219a36ba
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dil-dot-nsl-ep-err.js
@@ -0,0 +1,29 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not appear between `.` and ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+10._e1
diff --git a/test/language/literals/numeric/numeric-separator-literal-dil-dot-nsl-err.js b/test/language/literals/numeric/numeric-separator-literal-dil-dot-nsl-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..6d7542eb79328389ff7d83ad8b5991c638d3a190
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dil-dot-nsl-err.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not be the last digit character of a
+ DecimalLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ DecimalIntegerLiteral . DecimalDigits_opt ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+10._
diff --git a/test/language/literals/numeric/numeric-separator-literal-dot-dd-nsl-dd-ep.js b/test/language/literals/numeric/numeric-separator-literal-dot-dd-nsl-dd-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..26cf232cf99e141c58c5e485fe41f95acf054151
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dot-dd-nsl-dd-ep.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `.` DecimalDigit NumericLiteralSeparator DecimalDigit ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+---*/
+
+assert.sameValue(.0_1e2, .01e2);
diff --git a/test/language/literals/numeric/numeric-separator-literal-dot-dd-nsl-dds-ep.js b/test/language/literals/numeric/numeric-separator-literal-dot-dd-nsl-dds-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..0ded986ab66fdd7c9a240e93a8664414f4f23560
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dot-dd-nsl-dds-ep.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `.` DecimalDigit NumericLiteralSeparator DecimalDigits ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+---*/
+
+assert.sameValue(.1_01e2, .101e2);
diff --git a/test/language/literals/numeric/numeric-separator-literal-dot-dds-nsl-dd-ep.js b/test/language/literals/numeric/numeric-separator-literal-dot-dds-nsl-dd-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..e3acbad8a23e2e9e63a8aff074b6655601f88245
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dot-dds-nsl-dd-ep.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `.` DecimalDigits NumericLiteralSeparator DecimalDigit ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+---*/
+
+assert.sameValue(.10_1e2, .101e2);
diff --git a/test/language/literals/numeric/numeric-separator-literal-dot-dds-nsl-dds-ep.js b/test/language/literals/numeric/numeric-separator-literal-dot-dds-nsl-dds-ep.js
new file mode 100644
index 0000000000000000000000000000000000000000..c437ef997c65e65b1e000fda2871a0115d991f3c
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dot-dds-nsl-dds-ep.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `.` DecimalDigits NumericLiteralSeparator DecimalDigits ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+---*/
+
+assert.sameValue(.00_01e2, .0001e2);
diff --git a/test/language/literals/numeric/numeric-separator-literal-dot-dds-nsl-ep-err.js b/test/language/literals/numeric/numeric-separator-literal-dot-dds-nsl-ep-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..f968e63d6c1635b0d9b70bb846c8fd72417b39a6
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dot-dds-nsl-ep-err.js
@@ -0,0 +1,28 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: NumericLiteralSeparator may not appear adjacent to ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+.0_e1
diff --git a/test/language/literals/numeric/numeric-separator-literal-dot-nsl-ep-err.js b/test/language/literals/numeric/numeric-separator-literal-dot-nsl-ep-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..df26f129d56cdd58c56cd58148f35826ef6d3142
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dot-nsl-ep-err.js
@@ -0,0 +1,29 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not appear between `.` and ExponentPart
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+ ExponentIndicator :: one of
+ e E
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+._e1
diff --git a/test/language/literals/numeric/numeric-separator-literal-dot-nsl-err.js b/test/language/literals/numeric/numeric-separator-literal-dot-nsl-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..322dcbf8ee62079cd4b514fb36d92aa55761b623
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-dot-nsl-err.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not be the last digit character of a
+ DecimalLiteral, nor adjacent to `.`
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalLiteral ::
+ . DecimalDigits ExponentPart_opt
+
+ DecimalDigits ::
+ ...
+ DecimalDigits NumericLiteralSeparator DecimalDigit
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+._
diff --git a/test/language/literals/numeric/numeric-separator-literal-hil-hd-nsl-hd-err.js b/test/language/literals/numeric/numeric-separator-literal-hil-hd-nsl-hd-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..d4f73eed20f78215a98d2527122040f9aa7f78e2
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-hil-hd-nsl-hd-err.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not be the appear adjacent to `0x` | `0X` in a
+ HexIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0x_1
diff --git a/test/language/literals/numeric/numeric-separator-literal-hil-hd-nsl-hd.js b/test/language/literals/numeric/numeric-separator-literal-hil-hd-nsl-hd.js
new file mode 100644
index 0000000000000000000000000000000000000000..f8a33c65f45e93ff7396fd66a9ff671213e24e05
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-hil-hd-nsl-hd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0x` | `0X` HexDigit NumericLiteralSeparator HexDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+---*/
+
+assert.sameValue(0x0_1, 0x01);
+assert.sameValue(0X0_1, 0X01);
diff --git a/test/language/literals/numeric/numeric-separator-literal-hil-hd-nsl-hds.js b/test/language/literals/numeric/numeric-separator-literal-hil-hd-nsl-hds.js
new file mode 100644
index 0000000000000000000000000000000000000000..0561c9ad95dbbafda73f4a4eac9e88db74b15b03
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-hil-hd-nsl-hds.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0x` | `0X` HexDigit NumericLiteralSeparator HexDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+---*/
+
+assert.sameValue(0x0_10, 0x010);
+assert.sameValue(0X0_10, 0X010);
diff --git a/test/language/literals/numeric/numeric-separator-literal-hil-hds-nsl-hd.js b/test/language/literals/numeric/numeric-separator-literal-hil-hds-nsl-hd.js
new file mode 100644
index 0000000000000000000000000000000000000000..6dff72fa38b762873522f017947dd8494c795c4a
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-hil-hds-nsl-hd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0x` | `0X` HexDigits NumericLiteralSeparator HexDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+---*/
+
+assert.sameValue(0x01_0, 0x010);
+assert.sameValue(0X01_0, 0X010);
diff --git a/test/language/literals/numeric/numeric-separator-literal-hil-hds-nsl-hds.js b/test/language/literals/numeric/numeric-separator-literal-hil-hds-nsl-hds.js
new file mode 100644
index 0000000000000000000000000000000000000000..2672484cbca266b21d875f742ef0ba87aad4c68e
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-hil-hds-nsl-hds.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0x` | `0X` HexDigits NumericLiteralSeparator HexDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+---*/
+
+assert.sameValue(0x01_00, 0x0100);
+assert.sameValue(0X01_00, 0X0100);
diff --git a/test/language/literals/numeric/numeric-separator-literal-hil-nsl-hd-dunder-err.js b/test/language/literals/numeric/numeric-separator-literal-hil-nsl-hd-dunder-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..dcf0f40a37d131f9fa24af284e3b8703da3e45e0
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-hil-nsl-hd-dunder-err.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not appear adjacent to another
+ NumericLiteralSeparator in a HexIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0x0__0
diff --git a/test/language/literals/numeric/numeric-separator-literal-hil-nsl-hd-err.js b/test/language/literals/numeric/numeric-separator-literal-hil-nsl-hd-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..7205cbb2198989b501acc235f128ef2881ce2728
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-hil-nsl-hd-err.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not be the last digit character of a
+ HexIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0x0_
diff --git a/test/language/literals/numeric/numeric-separator-literal-hil-od-nsl-od-one-of.js b/test/language/literals/numeric/numeric-separator-literal-hil-od-nsl-od-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..3f81986dd5d99f4dcbac4169f2d63679fbd46aee
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-hil-od-nsl-od-one-of.js
@@ -0,0 +1,47 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0x` | `0X` HexDigit NumericLiteralSeparator HexDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ HexIntegerLiteral ::
+ 0x HexDigits
+ 0X HexDigits
+
+ HexDigits ::
+ HexDigit
+ HexDigits HexDigit
+ HexDigits NumericLiteralSeparator HexDigit
+
+ HexDigit::one of
+ 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
+
+---*/
+
+assert.sameValue(0x0_0, 0x00);
+assert.sameValue(0x1_1, 0x11);
+assert.sameValue(0x2_2, 0x22);
+assert.sameValue(0x3_3, 0x33);
+assert.sameValue(0x4_4, 0x44);
+assert.sameValue(0x5_5, 0x55);
+assert.sameValue(0x6_6, 0x66);
+assert.sameValue(0x7_7, 0x77);
+assert.sameValue(0x8_8, 0x88);
+assert.sameValue(0x9_9, 0x99);
+assert.sameValue(0xa_a, 0xaa);
+assert.sameValue(0xb_b, 0xbb);
+assert.sameValue(0xc_c, 0xcc);
+assert.sameValue(0xd_d, 0xdd);
+assert.sameValue(0xe_e, 0xee);
+assert.sameValue(0xf_f, 0xff);
+assert.sameValue(0xA_A, 0xAA);
+assert.sameValue(0xB_B, 0xBB);
+assert.sameValue(0xC_C, 0xCC);
+assert.sameValue(0xD_D, 0xDD);
+assert.sameValue(0xE_E, 0xEE);
+assert.sameValue(0xF_F, 0xFF);
diff --git a/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dd-one-of.js b/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dd-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..528546e4b1c0705e0a47ac2ee26386687f68b46f
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dd-one-of.js
@@ -0,0 +1,38 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: NonZeroDigit NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+ NonZeroDigit :: one of
+ 1 2 3 4 5 6 7 8 9
+
+ DecimalDigits ::
+ DecimalDigit
+ ...
+
+ DecimalDigit :: one of
+ 0 1 2 3 4 5 6 7 8 9
+
+---*/
+
+assert.sameValue(1_0, 10);
+assert.sameValue(1_1, 11);
+assert.sameValue(2_2, 22);
+assert.sameValue(3_3, 33);
+assert.sameValue(4_4, 44);
+assert.sameValue(5_5, 55);
+assert.sameValue(6_6, 66);
+assert.sameValue(7_7, 77);
+assert.sameValue(8_8, 88);
+assert.sameValue(9_9, 99);
+
+
diff --git a/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dd.js b/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..3f6e166a838edee8407fa9eaca9132de1e458f9c
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dd.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: NonZeroDigit NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+ NonZeroDigit :: one of
+ 1 2 3 4 5 6 7 8 9
+
+ DecimalDigits ::
+ ...
+ DecimalDigits DecimalDigit
+ ...
+
+---*/
+
+assert.sameValue(1_1, 11);
diff --git a/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dds-dunder-err.js b/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dds-dunder-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..dd2f133fa084a9889db9d80ca78f966da2769f1e
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dds-dunder-err.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not appear adjacent to another
+ NumericLiteralSeparator in DecimalIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+ NonZeroDigit :: one of
+ 1 2 3 4 5 6 7 8 9
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0__0123456789
diff --git a/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dds-leading-zero-err.js b/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dds-leading-zero-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..201ac0acdf082e688b90f8ae76f82af8cfecbe2e
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dds-leading-zero-err.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: NonZeroDigit NumericLiteralSeparator DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator DecimalDigits
+
+ NonZeroDigit :: one of
+ 1 2 3 4 5 6 7 8 9
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0_0123456789
diff --git a/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dds.js b/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dds.js
new file mode 100644
index 0000000000000000000000000000000000000000..47ea301dace17a4346378360b533ebd361059a7d
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-nzd-nsl-dds.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: NonZeroDigit NumericLiteralSeparator DecimalDigits
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ DecimalIntegerLiteral ::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+ NonZeroDigit :: one of
+ 1 2 3 4 5 6 7 8 9
+
+ DecimalDigits ::
+ ...
+ DecimalDigits DecimalDigit
+ ...
+
+---*/
+
+assert.sameValue(1_0123456789, 10123456789);
diff --git a/test/language/literals/numeric/numeric-separator-literal-oil-nsl-od-dunder-err.js b/test/language/literals/numeric/numeric-separator-literal-oil-nsl-od-dunder-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..9be6a2b73fc12bf15c2e14d90efe414d5dfa3418
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-oil-nsl-od-dunder-err.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not appear adjacent to another
+ NumericLiteralSeparator in a OctalIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0o0__0
diff --git a/test/language/literals/numeric/numeric-separator-literal-oil-nsl-od-err.js b/test/language/literals/numeric/numeric-separator-literal-oil-nsl-od-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..1d8b21e8399be5b351880d379e284c18e6b011af
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-oil-nsl-od-err.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not be the last digit character of an
+ OctalIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0o0_
diff --git a/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-od-err.js b/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-od-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..34276984f853640c616a3b18fb25552c17746d27
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-od-err.js
@@ -0,0 +1,32 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NumericLiteralSeparator may not be the appear adjacent to `0o` | `0O` in a
+ OctalIntegerLiteral
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+0o_1
diff --git a/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-od-one-of.js b/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-od-one-of.js
new file mode 100644
index 0000000000000000000000000000000000000000..f9d0f6b16f416a14c9d0d1f529e79cbea36f5bb1
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-od-one-of.js
@@ -0,0 +1,33 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0o` | `0O` OctalDigit NumericLiteralSeparator OctalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+---*/
+
+assert.sameValue(0o0_0, 0o00);
+assert.sameValue(0o1_1, 0o11);
+assert.sameValue(0o2_2, 0o22);
+assert.sameValue(0o3_3, 0o33);
+assert.sameValue(0o4_4, 0o44);
+assert.sameValue(0o5_5, 0o55);
+assert.sameValue(0o6_6, 0o66);
+assert.sameValue(0o7_7, 0o77);
diff --git a/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-od.js b/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-od.js
new file mode 100644
index 0000000000000000000000000000000000000000..8555afc406e1e9fce27aef8cb36ccda44a3f532f
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-od.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0o` | `0O` OctalDigit NumericLiteralSeparator OctalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+---*/
+
+assert.sameValue(0o0_1, 0o01);
+assert.sameValue(0O0_1, 0O01);
diff --git a/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-ods.js b/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-ods.js
new file mode 100644
index 0000000000000000000000000000000000000000..70bc8396dabe0c81d3ebcfd62f48a31539cc2398
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-oil-od-nsl-ods.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0o` | `0O` OctalDigit NumericLiteralSeparator OctalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+---*/
+
+assert.sameValue(0o0_10, 0o010);
+assert.sameValue(0O0_10, 0O010);
diff --git a/test/language/literals/numeric/numeric-separator-literal-oil-ods-nsl-od.js b/test/language/literals/numeric/numeric-separator-literal-oil-ods-nsl-od.js
new file mode 100644
index 0000000000000000000000000000000000000000..7083418e11e4e4182b4716d7fd6532fed228993f
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-oil-ods-nsl-od.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0o` | `0O` OctalDigits NumericLiteralSeparator OctalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+---*/
+
+assert.sameValue(0o01_0, 0o010);
+assert.sameValue(0O01_0, 0O010);
diff --git a/test/language/literals/numeric/numeric-separator-literal-oil-ods-nsl-ods.js b/test/language/literals/numeric/numeric-separator-literal-oil-ods-nsl-ods.js
new file mode 100644
index 0000000000000000000000000000000000000000..2e33e076f77c28899025d582258630f6b515855b
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-oil-ods-nsl-ods.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ `0o` | `0O` OctalDigits NumericLiteralSeparator OctalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ OctalIntegerLiteral ::
+ 0o OctalDigits
+ 0O OctalDigits
+
+ OctalDigits ::
+ OctalDigit
+ OctalDigits OctalDigit
+ OctalDigits NumericLiteralSeparator OctalDigit
+
+ OctalDigit :: one of
+ 0 1 2 3 4 5 6 7
+
+---*/
+
+assert.sameValue(0o01_00, 0o0100);
+assert.sameValue(0O01_00, 0O0100);
diff --git a/test/language/literals/numeric/numeric-separator-literal-sign-minus-dds-nsl-dd.js b/test/language/literals/numeric/numeric-separator-literal-sign-minus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..e11952a61f15ccb82d533e88d46f1b60ad720701
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-sign-minus-dds-nsl-dd.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: DecimalDigits NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ SignedInteger ::
+ ...
+ - DecimalDigits
+
+---*/
+
+assert.sameValue(-123456789_0, -1234567890);
+assert.sameValue(-123456789_1, -1234567891);
+assert.sameValue(-123456789_2, -1234567892);
+assert.sameValue(-123456789_3, -1234567893);
+assert.sameValue(-123456789_4, -1234567894);
+assert.sameValue(-123456789_5, -1234567895);
+assert.sameValue(-123456789_6, -1234567896);
+assert.sameValue(-123456789_7, -1234567897);
+assert.sameValue(-123456789_8, -1234567898);
+assert.sameValue(-123456789_9, -1234567899);
diff --git a/test/language/literals/numeric/numeric-separator-literal-sign-plus-dds-nsl-dd.js b/test/language/literals/numeric/numeric-separator-literal-sign-plus-dds-nsl-dd.js
new file mode 100644
index 0000000000000000000000000000000000000000..89050f1a45c2a3ba2d20eb5f460715f3029e5b95
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-sign-plus-dds-nsl-dd.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: DecimalDigits NumericLiteralSeparator DecimalDigit
+info: |
+ NumericLiteralSeparator ::
+ _
+
+ SignedInteger ::
+ ...
+ + DecimalDigits
+ ...
+
+---*/
+
+assert.sameValue(+123456789_0, 1234567890);
+assert.sameValue(+123456789_1, 1234567891);
+assert.sameValue(+123456789_2, 1234567892);
+assert.sameValue(+123456789_3, 1234567893);
+assert.sameValue(+123456789_4, 1234567894);
+assert.sameValue(+123456789_5, 1234567895);
+assert.sameValue(+123456789_6, 1234567896);
+assert.sameValue(+123456789_7, 1234567897);
+assert.sameValue(+123456789_8, 1234567898);
+assert.sameValue(+123456789_9, 1234567899);
diff --git a/test/language/literals/numeric/numeric-separator-literal-unicode-err.js b/test/language/literals/numeric/numeric-separator-literal-unicode-err.js
new file mode 100644
index 0000000000000000000000000000000000000000..4674392f36aa081822fdd1039bdb563fa7d36c7e
--- /dev/null
+++ b/test/language/literals/numeric/numeric-separator-literal-unicode-err.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: prod-NumericLiteralSeparator
+description: >
+ NonZeroDigit NumericLiteralSeparator DecimalDigits sequence expressed with
+ unicode escape sequence
+info: |
+ NumericLiteralSeparator::
+ _
+
+ DecimalIntegerLiteral::
+ ...
+ NonZeroDigit NumericLiteralSeparator_opt DecimalDigits
+
+negative:
+ phase: early
+ type: SyntaxError
+---*/
+
+throw "Test262: This statement should not be evaluated.";
+
+1\u005F0123456789