Update and expand tests for isFinite

test/built-ins/isFinite/toprimitive-valid-result.js

+// Copyright (C) 2016 The V8 Project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-isfinite-number
+es6id: 18.2.2
+description: >
+  Use non-object value returned from @@toPrimitive method
+info: |
+  isFinite (number)
+
+  1. Let num be ? ToNumber(number).
+
+  ToPrimitive ( input [ , PreferredType ] )
+
+  [...]
+  4. Let exoticToPrim be ? GetMethod(input, @@toPrimitive).
+  5. If exoticToPrim is not undefined, then
+    a. Let result be ? Call(exoticToPrim, input, « hint »).
+    b. If Type(result) is not Object, return result.
+features: [Symbol.toPrimitive]
+---*/
+
+var called = 0;
+var obj = {
+  valueOf: function() {
+    called = NaN;
+    return Infinity;
+  },
+  toString: function() {
+    called = NaN;
+    return Infinity;
+  }
+};
+
+obj[Symbol.toPrimitive] = function() {
+  called += 1;
+  return 42;
+};
+assert.sameValue(isFinite(obj), true, "use returned value - number");
+assert.sameValue(called, 1, "toPrimitive is called - number");
+
+called = 0;
+obj[Symbol.toPrimitive] = function() {
+  called += 1;
+  return "42";
+};
+assert.sameValue(isFinite(obj), true, "use returned value - string");
+assert.sameValue(called, 1, "toPrimitive is called - string");
+
+called = 0;
+obj[Symbol.toPrimitive] = function() {
+  called += 1;
+  return true;
+};
+assert.sameValue(isFinite(obj), true, "use returned value - boolean true");
+assert.sameValue(called, 1, "toPrimitive is called - boolean true");
+
+called = 0;
+obj[Symbol.toPrimitive] = function() {
+  called += 1;
+  return false;
+};
+assert.sameValue(isFinite(obj), true, "use returned value - boolean false");
+assert.sameValue(called, 1, "toPrimitive is called - boolean false");
+
+called = 0;
+obj[Symbol.toPrimitive] = function() {
+  called += 1;
+  return Infinity;
+};
+assert.sameValue(isFinite(obj), false, "use returned value - Infinity");
+assert.sameValue(called, 1, "toPrimitive is called - Infinity");
+
+called = 0;
+obj[Symbol.toPrimitive] = function() {
+  called += 1;
+  return -Infinity;
+};
+assert.sameValue(isFinite(obj), false, "use returned value - -Infinity");
+assert.sameValue(called, 1, "toPrimitive is called - -Infinity");