diff --git a/test/language/comments/hashbang-encoded-bang.js b/test/language/comments/hashbang-encoded-bang.js
new file mode 100644
index 0000000000000000000000000000000000000000..0d8f8d9fabc760417e12a629890d5906fafa7c16
--- /dev/null
+++ b/test/language/comments/hashbang-encoded-bang.js
@@ -0,0 +1,10 @@
+#\u0021
+/*---
+esid: pending
+description: >
+    Hashbang comments should not be allowed to have encoded characters
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+---*/
diff --git a/test/language/comments/hashbang-encoded-hash.js b/test/language/comments/hashbang-encoded-hash.js
new file mode 100644
index 0000000000000000000000000000000000000000..6d29abd2fc0f32a441f1c905527ec232cd91d8bd
--- /dev/null
+++ b/test/language/comments/hashbang-encoded-hash.js
@@ -0,0 +1,10 @@
+\u0023!
+/*---
+esid: pending
+description: >
+    Hashbang comments should not be allowed to have encoded characters
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+---*/
diff --git a/test/language/comments/hashbang-encoded-hashbang.js b/test/language/comments/hashbang-encoded-hashbang.js
new file mode 100644
index 0000000000000000000000000000000000000000..629bda6a7803b1521ece41a5794c5cb46f26ca44
--- /dev/null
+++ b/test/language/comments/hashbang-encoded-hashbang.js
@@ -0,0 +1,10 @@
+\u0023\u0021
+/*---
+esid: pending
+description: >
+    Hashbang comments should not be allowed to have encoded characters
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+---*/
diff --git a/test/language/comments/hashbang-eval.js b/test/language/comments/hashbang-eval.js
new file mode 100644
index 0000000000000000000000000000000000000000..8f69cd81bcbfb3999790aac2dc9641c20e0688b2
--- /dev/null
+++ b/test/language/comments/hashbang-eval.js
@@ -0,0 +1,10 @@
+/*---
+esid: pending
+description: >
+    Hashbang comments should be available in Script evaluator contexts.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+---*/
+
+assert.sameValue(eval('#!\n'), undefined);
diff --git a/test/language/comments/hashbang-function-body.js b/test/language/comments/hashbang-function-body.js
new file mode 100644
index 0000000000000000000000000000000000000000..2bb5130902ac9be95e0af9971f4e482a74fc65dc
--- /dev/null
+++ b/test/language/comments/hashbang-function-body.js
@@ -0,0 +1,14 @@
+/*---
+esid: pending
+description: >
+    Hashbang comments should only be allowed at the start of source texts and should not be allowed within function bodies.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+negative:
+  phase: parse
+  type: SyntaxError
+---*/
+function fn() {#!
+}
diff --git a/test/language/comments/hashbang-function-constructor.js b/test/language/comments/hashbang-function-constructor.js
new file mode 100644
index 0000000000000000000000000000000000000000..fdc3f85bab7c2c04bd8b9d478833b7c9e9baae96
--- /dev/null
+++ b/test/language/comments/hashbang-function-constructor.js
@@ -0,0 +1,22 @@
+/*---
+esid: pending
+description: >
+    Hashbang comments should not be allowed in function evaluator contexts.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+---*/
+const AsyncFunction = (async function (){}).constructor;
+const GeneratorFunction = (function *(){}).constructor;
+const AsyncGeneratorFunction = (async function *(){}).constructor;
+for (ctor of [
+  Function,
+  AsyncFunction,
+  GeneratorFunction,
+  AsyncGeneratorFunction,
+]) {
+  assert.throws(SyntaxError, () => ctor('#!\n_',''), `${ctor.name} Call argument`);
+  assert.throws(SyntaxError, () => ctor('#!\n_'), `${ctor.name} Call body`);
+  assert.throws(SyntaxError, () => new ctor('#!\n_',''), `${ctor.name} Construct argument`);
+  assert.throws(SyntaxError, () => new ctor('#!\n_'), `${ctor.name} Construct body`);
+}
diff --git a/test/language/comments/hashbang-module.js b/test/language/comments/hashbang-module.js
new file mode 100644
index 0000000000000000000000000000000000000000..ea30c700f69fd590337369aee7a40ca4a532f23e
--- /dev/null
+++ b/test/language/comments/hashbang-module.js
@@ -0,0 +1,10 @@
+#!
+/*---
+esid: pending
+description: >
+    Hashbang comments should be allowed in Modules.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [module]
+---*/
diff --git a/test/language/comments/hashbang-multi-line-comment.js b/test/language/comments/hashbang-multi-line-comment.js
new file mode 100644
index 0000000000000000000000000000000000000000..27bc551e4f534b84fbcad0474cf17332ac9eaba9
--- /dev/null
+++ b/test/language/comments/hashbang-multi-line-comment.js
@@ -0,0 +1,15 @@
+#!/*
+these characters should not be considered within a comment
+*/
+/*---
+esid: pending
+description: >
+    Hashbang comments should not interpret multi-line comments.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+negative:
+  phase: parse
+  type: SyntaxError
+---*/
\ No newline at end of file
diff --git a/test/language/comments/hashbang-no-line-separator.js b/test/language/comments/hashbang-no-line-separator.js
new file mode 100644
index 0000000000000000000000000000000000000000..824d903d9fe38aee7cac8aff8982eecc4440dfbb
--- /dev/null
+++ b/test/language/comments/hashbang-no-line-separator.js
@@ -0,0 +1,11 @@
+/*---
+esid: pending
+description: >
+    Hashbang comments should not require a newline afterwards
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+---*/
+
+eval('#!');
diff --git a/test/language/comments/hashbang-not-empty.js b/test/language/comments/hashbang-not-empty.js
new file mode 100644
index 0000000000000000000000000000000000000000..b005a3f290c6a5c8cbe5643c59ba5842f9fabcef
--- /dev/null
+++ b/test/language/comments/hashbang-not-empty.js
@@ -0,0 +1,11 @@
+#! these characters should be treated as a comment
+/*---
+esid: pending
+description: >
+    Hashbang comments should be allowed in Scripts and should not be required to be empty.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+---*/
+
diff --git a/test/language/comments/hashbang-preceding-directive-prologue.js b/test/language/comments/hashbang-preceding-directive-prologue.js
new file mode 100644
index 0000000000000000000000000000000000000000..edd975cfb7d689f0a1d24628f82c22ca252331b6
--- /dev/null
+++ b/test/language/comments/hashbang-preceding-directive-prologue.js
@@ -0,0 +1,14 @@
+"use strict"
+#!
+/*---
+esid: pending
+description: >
+    Hashbang comments should only be allowed at start of source texts and should not be preceded by DirectivePrologues.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+negative:
+  phase: parse
+  type: SyntaxError
+---*/
\ No newline at end of file
diff --git a/test/language/comments/hashbang-preceding-empty-statement.js b/test/language/comments/hashbang-preceding-empty-statement.js
new file mode 100644
index 0000000000000000000000000000000000000000..bff2aa6d8f09a8fdc658e58b8a349b3052a97e7f
--- /dev/null
+++ b/test/language/comments/hashbang-preceding-empty-statement.js
@@ -0,0 +1,13 @@
+;#!
+/*---
+esid: pending
+description: >
+    Hashbang comments should only be allowed at the start of source texts and should not be preceded by empty statements.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+negative:
+  phase: parse
+  type: SyntaxError
+---*/
\ No newline at end of file
diff --git a/test/language/comments/hashbang-preceding-hashbang.js b/test/language/comments/hashbang-preceding-hashbang.js
new file mode 100644
index 0000000000000000000000000000000000000000..27d079ddf529ab046894172e861445b30bf03ebf
--- /dev/null
+++ b/test/language/comments/hashbang-preceding-hashbang.js
@@ -0,0 +1,14 @@
+#!
+#!
+/*---
+esid: pending
+description: >
+    Hashbang comments should only be allowed at the start of source texts and should not be preceded by Hashbang comments.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+negative:
+  phase: parse
+  type: SyntaxError
+---*/
\ No newline at end of file
diff --git a/test/language/comments/hashbang-preceding-line-comment.js b/test/language/comments/hashbang-preceding-line-comment.js
new file mode 100644
index 0000000000000000000000000000000000000000..365b5dc4ddd0d292bbd68599fc9b384a72a91976
--- /dev/null
+++ b/test/language/comments/hashbang-preceding-line-comment.js
@@ -0,0 +1,14 @@
+//
+#!
+/*---
+esid: pending
+description: >
+    Hashbang comments should only be allowed at the start of source texts and should not be preceded by line comments.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+negative:
+  phase: parse
+  type: SyntaxError
+---*/
\ No newline at end of file
diff --git a/test/language/comments/hashbang-preceding-multi-line-comment.js b/test/language/comments/hashbang-preceding-multi-line-comment.js
new file mode 100644
index 0000000000000000000000000000000000000000..5145019f0442adc80f9fe68a915e085ba96c9e2d
--- /dev/null
+++ b/test/language/comments/hashbang-preceding-multi-line-comment.js
@@ -0,0 +1,14 @@
+/*
+*/#!
+/*---
+esid: pending
+description: >
+    Hashbang comments should only be allowed at the start of source texts and should not be preceded by multi-line comments.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+negative:
+  phase: parse
+  type: SyntaxError
+---*/
\ No newline at end of file
diff --git a/test/language/comments/hashbang-preceding-whitespace.js b/test/language/comments/hashbang-preceding-whitespace.js
new file mode 100644
index 0000000000000000000000000000000000000000..7be73bd36a5e892c1d1673f65154c050453c2dea
--- /dev/null
+++ b/test/language/comments/hashbang-preceding-whitespace.js
@@ -0,0 +1,13 @@
+    #!
+/*---
+esid: pending
+description: >
+    Hashbang comments should only be allowed at the start of source texts and should not be preceded by whitespace.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+negative:
+  phase: parse
+  type: SyntaxError
+---*/
\ No newline at end of file
diff --git a/test/language/comments/hashbang-statement-block.js b/test/language/comments/hashbang-statement-block.js
new file mode 100644
index 0000000000000000000000000000000000000000..62ce7af3cc901556df0475e964ec8ba606a6b319
--- /dev/null
+++ b/test/language/comments/hashbang-statement-block.js
@@ -0,0 +1,15 @@
+/*---
+esid: pending
+description: >
+    Hashbang comments should only be allowed at the start of source texts and should not be allowed within blocks.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+negative:
+  phase: parse
+  type: SyntaxError
+---*/
+{
+  #!
+}
\ No newline at end of file
diff --git a/test/language/comments/hashbang-use-strict.js b/test/language/comments/hashbang-use-strict.js
new file mode 100644
index 0000000000000000000000000000000000000000..d8a7a5e8b9c1a9adcdb798176aed60c3775cc37f
--- /dev/null
+++ b/test/language/comments/hashbang-use-strict.js
@@ -0,0 +1,12 @@
+#!"use strict"
+/*---
+esid: pending
+description: >
+    Hashbang comments should not be interpretted and should not generate DirectivePrologues.
+info: |
+    HashbangComment::
+      #! SingleLineCommentChars[opt]
+flags: [raw]
+---*/
+
+with ({}) {}