additional BigInt JSON tests (#1235)

* additional BigInt JSON tests

* single quotes

* BigInt stringify order of steps

test/built-ins/JSON/stringify/bigint-order.js

@@ -0,0 +1,42 @@
+// Copyright (C) 2017 Robin Templeton. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: BigInt stringify order of steps
+esid: sec-serializejsonproperty
+info: >
+  Runtime Semantics: SerializeJSONProperty ( key, holder )
+
+  2. If Type(value) is Object or BigInt, then
+    a. Let toJSON be ? GetGetV(value, "toJSON").
+    b. If IsCallable(toJSON) is true, then
+      i. Set value to ? Call(toJSON, value, « key »).
+  3. If ReplacerFunction is not undefined, then
+    a. Set value to ? Call(ReplacerFunction, holder, « key, value »).
+  4. If Type(value) is Object, then
+    [...]
+    d. Else if value has a [[BigIntData]] internal slot, then
+      i. Set value to value.[[BigIntData]].
+  [...]
+  10. If Type(value) is BigInt, throw a TypeError exception
+features: [BigInt, arrow-function]
+---*/
+
+let step;
+
+function replacer(x, k, v)
+{
+  assert.sameValue(step++, 1);
+  assert.sameValue(v, 1n);
+  return x;
+}
+
+BigInt.prototype.toJSON = function () { assert.sameValue(step++, 0); return 1n; };
+
+step = 0;
+assert.throws(TypeError, () => JSON.stringify(0n, (k, v) => replacer(2n, k, v)));
+assert.sameValue(step, 2);
+
+step = 0;
+assert.throws(TypeError, () => JSON.stringify(0n, (k, v) => replacer(Object(2n), k, v)));
+assert.sameValue(step, 2);

test/built-ins/JSON/stringify/bigint-replacer.js

@@ -0,0 +1,24 @@
+// Copyright (C) 2017 Robin Templeton. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: JSON serialization of BigInt values with replacer
+esid: sec-serializejsonproperty
+info: >
+  Runtime Semantics: SerializeJSONProperty ( key, holder )
+
+  3. If ReplacerFunction is not undefined, then
+    a. Set value to ? Call(ReplacerFunction, holder, « key, value »).
+features: [BigInt]
+---*/
+
+function replacer(k, v)
+{
+    if (typeof v === "bigint")
+        return "bigint";
+    else
+        return v;
+}
+
+assert.sameValue(JSON.stringify(0n, replacer), '"bigint"');
+assert.sameValue(JSON.stringify({x: 0n}, replacer), '{"x":"bigint"}');

test/built-ins/JSON/stringify/bigint-tojson.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.
+
+/*---
+description: BigInt toJSON method
+esid: sec-serializejsonproperty
+info: >
+  Runtime Semantics: SerializeJSONProperty ( key, holder )
+
+  2. If Type(value) is Object or BigInt, then
+    a. Let toJSON be ? GetGetV(value, "toJSON").
+    b. If IsCallable(toJSON) is true, then
+      i. Set value to ? Call(toJSON, value, « key »).
+features: [BigInt]
+---*/
+
+BigInt.prototype.toJSON = function () { return this.toString(); };
+assert.sameValue(JSON.stringify(0n), '"0"');

test/built-ins/JSON/stringify/bigint.js

@@ -8,3 +8,5 @@ features: [BigInt]
 ---*/
 
 assert.throws(TypeError, () => JSON.stringify(0n));
+assert.throws(TypeError, () => JSON.stringify(Object(0n)));
+assert.throws(TypeError, () => JSON.stringify({x: 0n}));