mirror of
https://github.com/tc39/test262.git
synced 2025-04-08 19:35:28 +02:00
4273ad1fa7
Files whose name ends in `_.js` are not themselves valid Test262 tests
and should not be interpreted as such by test runners.
---
Because the tests in this patch concern declaration *instantiation*,
care has been taken to avoid asserting binding values following
evaluation. Because a given module's dependencies are evaluated prior to
the module itself, this is only observable in modules which import their
own bindings.
A separate patch dedicated to the evaluation of module code asserts the
behavior of bindings following evaluation.
---
For tests that concern the creation of a module namespace object, this
patch relies on the semantics of the `in` operator. The `in` operator
uses the [[HasProperty]] internal method and avoids testing unrelated
semantics concerning binding resolution. Those semantics should be
explicitly asserted with a separate set of tests dedicated to that
purpose.
---
One test case which is notably missing is error resulting from a cycle
due to an `import` declaration (under the current file naming scheme,
such a test might be named `instn-named-err-circular.js`). Due to the
recursive nature of ModuleDeclarationInstantiation, it is not
technically possible for a circular request to be found in step 12.c.i.
Cycles rely on at least 2 `export` declarations, and because these are
resolved *before* imports, any cycle would trigger failure prior to step
12.c.
---
One aspect of *module* resolution that makes ordering observable is the
fact that resolution can fail in two distinct ways (i.e. with a
SyntaxError or with a ReferenceError). This patch includes tests that
leverage this detail in order to assert that modules are resolved in the
correct sequence.
However, from the perspective of the ECMA-262 specification, the
ordering of *export* (e.g. binding) resolution is not observable. This
is due to restrictions on the grammar, where each export is independent.
When *export* resolution fails, it does so with instances of SyntaxError
alone, precluding the above strategy.
So while ModuleDeclarationInstantiation resolves the exports of the
module's dependencies in the following order:
1. "Indirect" exports, e.g.
- `export { x } from './y.js';`
- `export { x as z } from './y.js';`
- `import { x } from './y.js'; export { x };`
2. "Star" imports
- `import * as ns from './y.js';`
3. "Named" (my word) imports
- `import x from './y.js';`
- `import { x } from './y.js';`
- `import { x as z } from './y.js';`
Intentional failures cannot be used to discern resolution ordering.
54 lines
1.1 KiB
JavaScript
54 lines
1.1 KiB
JavaScript
// Copyright (C) 2016 the V8 project authors. All rights reserved.
|
|
// This code is governed by the BSD license found in the LICENSE file.
|
|
/*---
|
|
description: >
|
|
The first identifier in an ImportSpecifier containing `as` may be any valid
|
|
IdentifierName
|
|
esid: sec-imports
|
|
info: |
|
|
ImportSpecifier:
|
|
ImportedBinding
|
|
IdentifierName as ImportedBinding
|
|
flags: [module]
|
|
---*/
|
|
|
|
var _if = 1;
|
|
var _import = 2;
|
|
var _export = 3;
|
|
var _await = 4;
|
|
var _arguments = 5;
|
|
var _eval = 6;
|
|
var _default = 7;
|
|
var _as = 8;
|
|
|
|
export {
|
|
_if as if,
|
|
_import as import,
|
|
_export as export,
|
|
_await as await,
|
|
_arguments as arguments,
|
|
_eval as eval,
|
|
_default as default,
|
|
_as as as
|
|
};
|
|
|
|
import {
|
|
if as if_,
|
|
import as import_,
|
|
export as export_,
|
|
await as await_,
|
|
arguments as arguments_,
|
|
eval as eval_,
|
|
default as default_,
|
|
as as as
|
|
} from './instn-named-id-name.js';
|
|
|
|
assert.sameValue(if_, 1);
|
|
assert.sameValue(import_, 2);
|
|
assert.sameValue(export_, 3);
|
|
assert.sameValue(await_, 4);
|
|
assert.sameValue(arguments_, 5);
|
|
assert.sameValue(eval_, 6);
|
|
assert.sameValue(default_, 7);
|
|
assert.sameValue(as, 8);
|