Improve tests for BigInt.prototype.valueOf (#1256)

* Improve tests for BigInt.prototype.valueOf

* fixup! Improve tests for BigInt.prototype.valueOf

* fixup! Improve tests for BigInt.prototype.valueOf

* fixup! Improve tests for BigInt.prototype.valueOf

harness/typeCoercion.js

@@ -407,19 +407,3 @@ function testNotCoercibleToBigInt(test) {
   testStringValue("0xg");
   testStringValue("1n");
 }
-
-function testCoercibleToBigIntThisValue(value, test) {
-  test(value);
-  test(Object(value));
-}
-
-function testNotCoercibleToBigIntThisValue(test) {
-  test(undefined);
-  test(null);
-  test(true);
-  test(false);
-  test("");
-  test(Symbol(""));
-  test(0);
-  test({});
-}

test/built-ins/BigInt/prototype/valueOf/return.js

@@ -0,0 +1,18 @@
+// Copyright (C) 2017 Robin Templeton. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-bigint.prototype.valueof
+description: >
+  BigInt.prototype.valueOf returns the primitive BigInt value.
+info: |
+  BigInt.prototype.valueOf ( )
+
+  Return ? thisBigIntValue(this value). 
+features: [BigInt]
+---*/
+
+var valueOf = BigInt.prototype.valueOf;
+
+assert.sameValue(valueOf.call(0n), 0n, "0n");
+assert.sameValue(valueOf.call(Object(0n)), 0n, "Object(0n)");

test/built-ins/BigInt/prototype/valueOf/this-value-invalid-object-throws.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2017 Robin Templeton. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-bigint.prototype.valueof
+description: >
+  Throws a TypeError if this is an Object without a [[BigIntData]] internal.
+info: |
+  BigInt.prototype.valueOf ( )
+
+  1. Return ? thisBigIntValue(this value).
+
+  The abstract operation thisBigIntValue(value) performs the following steps:
+
+  1. If Type(value) is BigInt, return value.
+  2. If Type(value) is Object and value has a [[BigIntData]] internal slot, then
+    ...
+  3. Throw a TypeError exception.
+features: [BigInt]
+---*/
+
+var valueOf = BigInt.prototype.valueOf;
+
+assert.throws(TypeError, function() {
+  valueOf.call({});
+}, "{}");
+
+assert.throws(TypeError, function() {
+  valueOf.call(Object(1));
+}, "Object(1)");

test/built-ins/BigInt/prototype/valueOf/this-value-invalid-primitive-throws.js

@@ -0,0 +1,63 @@
+// Copyright (C) 2017 Robin Templeton. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-bigint.prototype.valueof
+description: >
+  Throws a TypeError if this is not a BigInt neither an Object.
+info: |
+  BigInt.prototype.valueOf ( )
+
+  1. Return ? thisBigIntValue(this value).
+
+  The abstract operation thisBigIntValue(value) performs the following steps:
+
+  1. If Type(value) is BigInt, return value.
+  2. If Type(value) is Object and value has a [[BigIntData]] internal slot, then
+    ...
+  3. Throw a TypeError exception.
+features: [BigInt, Symbol]
+---*/
+
+var valueOf = BigInt.prototype.valueOf;
+
+assert.throws(TypeError, function() {
+  valueOf.call(undefined);
+}, "undefined");
+
+assert.throws(TypeError, function() {
+  valueOf.call(null);
+}, "null");
+
+assert.throws(TypeError, function() {
+  valueOf.call(false);
+}, "false");
+
+assert.throws(TypeError, function() {
+  valueOf.call(true);
+}, "true");
+
+assert.throws(TypeError, function() {
+  valueOf.call("");
+}, "the empty string");
+
+assert.throws(TypeError, function() {
+  valueOf.call("1n");
+}, "string");
+
+assert.throws(TypeError, function() {
+  valueOf.call(0);
+}, "number (0)");
+
+assert.throws(TypeError, function() {
+  valueOf.call(1);
+}, "number (1)");
+
+assert.throws(TypeError, function() {
+  valueOf.call(NaN);
+}, "NaN");
+
+var s = Symbol();
+assert.throws(TypeError, function() {
+  valueOf.call(s);
+}, "symbol");