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// Check all the algorithms that call ToPrimitive. Confirm that they're passing
// the correct hint, per spec.
var STRING = "xyzzy";
var NUMBER = 42;
function assertCallsToPrimitive(f, expectedHint, expectedResult) {
var hint = undefined;
var testObj = {
[Symbol.toPrimitive](h) {
assertEq(hint, undefined);
hint = h;
return h === "number" ? NUMBER : STRING;
}
};
var result = f(testObj);
assertEq(hint, expectedHint, String(f));
assertEq(result, expectedResult, String(f));
}
// ToNumber
assertCallsToPrimitive(Number, "number", NUMBER);
// ToString
assertCallsToPrimitive(String, "string", STRING);
// ToPropertyKey
var obj = {[STRING]: "pass"};
assertCallsToPrimitive(key => obj[key], "string", "pass");
// Abstract Relational Comparison
assertCallsToPrimitive(x => x >= 42, "number", true);
assertCallsToPrimitive(x => x > "42", "number", false);
// Abstract Equality Comparison
assertCallsToPrimitive(x => x != STRING, "default", false);
assertCallsToPrimitive(x => STRING == x, "default", true);
assertCallsToPrimitive(x => x == NUMBER, "default", false);
assertCallsToPrimitive(x => NUMBER != x, "default", true);
// Addition
assertCallsToPrimitive(x => 1 + x, "default", "1" + STRING);
assertCallsToPrimitive(x => "" + x, "default", STRING);
// Date constructor
assertCallsToPrimitive(x => (new Date(x)).valueOf(), "default", Number(STRING));
// Date.prototype.toJSON
var expected = "a suffusion of yellow";
function testJSON(x) {
x.toJSON = Date.prototype.toJSON;
x.toISOString = function () { return expected; };
return JSON.stringify(x);
}
assertCallsToPrimitive(testJSON, "number", JSON.stringify(expected));
reportCompare(0, 0);
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