LayoutTests/js/script-tests/JSON-stringify-exposes-array-indices-as-strings.js

"use strict";

description("Verify that JSON.stringify passes keys as strings when calling toJSON or the replacer function.");

debug("Test Replacer Function");
var globalKey;
var globalValue;
var globalIndex = 0;
function replacer(key, value) {
    globalKey = key;
    globalValue = value;
    if (globalIndex == 0) {
        shouldBeEqualToString("typeof globalKey", "string");
        shouldBeEqualToString("globalKey", "");
        shouldBeEqualToString("typeof globalValue", "object");
        shouldBeTrue("globalValue instanceof Array");
        shouldBe("globalValue.length", "1");
        shouldBe("globalValue[0]", "42");
    } else if (globalIndex == 1) {
        globalKey = key;
        shouldBeEqualToString("typeof globalKey", "string");
        shouldBeEqualToString("globalKey", "0");
        shouldBeEqualToString("typeof globalValue", "number");
        shouldBe("globalValue", "42");
        value = 5;
    } else {
        shouldBeTrue(false);
    }
    ++globalIndex;
    return value;
}

shouldBeEqualToString("JSON.stringify([42], replacer)", "[5]");

debug("");
debug("Test toJSON Function");
var globalThis;
var toJSONArrayHelperCallCounter = 0;
var testObject = {
    toJSON: function(key) {
        globalThis = this;
        globalKey = key;
        shouldBe("toJSONArrayHelperCallCounter", "1");
        shouldBeTrue("globalThis === testObject");
        shouldBeEqualToString("typeof globalKey", "string");
        shouldBeEqualToString("globalKey", "0");
        return true;
    }
}

var testArray = [testObject];
function toJSONArrayHelper(key) {
    globalThis = this;
    globalKey = key;
    shouldBe("toJSONArrayHelperCallCounter", "0");
    shouldBeTrue("globalThis === testArray");
    shouldBeEqualToString("typeof globalKey", "string");
    shouldBeEqualToString("globalKey", "");
    ++toJSONArrayHelperCallCounter;
    return this;
}

Array.prototype.toJSON = toJSONArrayHelper;
shouldBeEqualToString("JSON.stringify(testArray)", "[true]");