stringify-toJSON-cache.js

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// Adding toJSON to a prototype must invalidate cached missing-toJSON lookups.

function testImpl(objStr, protoStr, expected, mutation) {

  let g = newGlobal({sameCompartmentAs: this});

  g.eval(`

    let obj = ${objStr};

    let proto = ${protoStr};

    for (var i = 0; i < 100; i++) {

      assertEq(JSONStringify(obj, "FastOnly"), '${expected}');

    ${mutation}

    assertEq(JSON.stringify(obj), '"called"');

`)

function test(objStr, protoStr, expected) {

  let defineDataProp = "proto.toJSON = () => 'called';";

  let defineGetter = "Object.defineProperty(proto, 'toJSON', { get() { return () => 'called'; }});";

  testImpl(objStr, protoStr, expected, defineDataProp);

  testImpl(objStr, protoStr, expected, defineGetter);

test("{a: 1}", "Object.prototype", '{"a":1}');

test("[1, 2]", "Array.prototype", '[1,2]');

let objStr = "Object.create({}, {a: {value: 1, enumerable: true}})";

let protoStr = "obj.__proto__";

test(objStr, protoStr, '{"a":1}');