test262/test/language/statements/class/subclass/default-constructor-spread-...

58 lines
1.7 KiB
JavaScript

// Copyright (C) 2016 André Bargull. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
esid: sec-runtime-semantics-classdefinitionevaluation
description: >
Default class constructor uses standard iterator spread semantics.
info: >
14.5.14 Runtime Semantics: ClassDefinitionEvaluation
...
10. If constructor is empty, then
a. If ClassHeritageopt is present, then
i Let constructor be the result of parsing the source text
constructor(...args){ super(...args); }
using the syntactic grammar with the goal symbol MethodDefinition.
...
14.1.19 Runtime Semantics: IteratorBindingInitialization
`FunctionRestParameter : BindingRestElement`
...
9. Let result be the result of performing IteratorBindingInitialization for BindingRestElement using iteratorRecord and environment as the arguments.
...
13.3.3.6 Runtime Semantics: IteratorBindingInitialization
`BindingRestElement : ...BindingIdentifier`
...
2. Let A be ArrayCreate(0).
...
12.3.6.1 Runtime Semantics: ArgumentListEvaluation
`ArgumentList : ArgumentList , ...AssignmentExpression`
...
3. Let iterator be ? GetIterator(? GetValue(spreadRef)).
...
features: [Symbol.iterator]
---*/
var arrayIterator = Array.prototype[Symbol.iterator];
// Redefine Array iterator to change the result of spreading `args` in `super(...args)`.
Array.prototype[Symbol.iterator] = function() {
return arrayIterator.call(["spread-value"]);
};
var receivedValue;
class Base {
constructor(value) {
receivedValue = value;
}
}
class Derived extends Base {}
new Derived();
assert.sameValue(receivedValue, "spread-value");