the statement `set Y to be the file system root` can be wrongly
interpreted as the file system root being updated to match Y,
removing the `be` term removes this potential interpretation
PR-URL: https://github.com/nodejs/node/pull/57092
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
This patch implements a "module-sync" exports condition
for packages to supply a sycnrhonous ES module to the
Node.js module loader, no matter it's being required
or imported. This is similar to the "module" condition
that bundlers have been using to support `require(esm)`
in Node.js, and allows dual-package authors to opt into
ESM-first only newer versions of Node.js that supports
require(esm) while avoiding the dual-package hazard.
```json
{
"type": "module",
"exports": {
"node": {
// On new version of Node.js, both require() and import get
// the ESM version
"module-sync": "./index.js",
// On older version of Node.js, where "module" and
// require(esm) are not supported, use the transpiled CJS version
// to avoid dual-package hazard. Library authors can decide
// to drop support for older versions of Node.js when they think
// it's time.
"default": "./dist/index.cjs"
},
// On any other environment, use the ESM version.
"default": "./index.js"
}
}
```
We end up implementing a condition with a different name
instead of reusing "module", because existing code in the
ecosystem using the "module" condition sometimes also expect
the module resolution for these ESM files to work in CJS
style, which is supported by bundlers, but the native
Node.js loader has intentionally made ESM resolution
different from CJS resolution (e.g. forbidding `import
'./noext'` or `import './directory'`), so it would be
semver-major to implement a `"module"` condition
without implementing the forbidden ESM resolution rules.
For now, this just implments a new condition as semver-minor
so it can be backported to older LTS.
Refs: https://webpack.js.org/guides/package-exports/#target-environment-independent-packages
PR-URL: https://github.com/nodejs/node/pull/54648
Fixes: https://github.com/nodejs/node/issues/52173
Refs: https://github.com/joyeecheung/test-module-condition
Refs: https://github.com/nodejs/node/issues/52697
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Tooling in the ecosystem have been using the __esModule property to
recognize transpiled ESM in consuming code. For example, a 'log'
package written in ESM:
export function log(val) { console.log(val); }
Can be transpiled as:
exports.__esModule = true;
exports.default = function log(val) { console.log(val); }
The consuming code may be written like this in ESM:
import log from 'log'
Which gets transpiled to:
const _mod = require('log');
const log = _mod.__esModule ? _mod.default : _mod;
So to allow transpiled consuming code to recognize require()'d real ESM
as ESM and pick up the default exports, we add a __esModule property by
building a source text module facade for any module that has a default
export and add .__esModule = true to the exports. We don't do this to
modules that don't have default exports to avoid the unnecessary
overhead. This maintains the enumerability of the re-exported names
and the live binding of the exports.
The source of the facade is defined as a constant per-isolate property
required_module_facade_source_string, which looks like this
export * from 'original';
export { default } from 'original';
export const __esModule = true;
And the 'original' module request is always resolved by
createRequiredModuleFacade() to wrap which is a ModuleWrap wrapping
over the original module.
PR-URL: https://github.com/nodejs/node/pull/52166
Refs: https://github.com/nodejs/node/issues/52134
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Filip Skokan <panva.ip@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Guy Bedford <guybedford@gmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
This patch:
1. Adds ESM syntax detection to compileFunctionForCJSLoader()
for --experimental-detect-module and allow it to emit the
warning for how to load ESM when it's used to parse ESM as
CJS but detection is not enabled.
2. Moves the ESM detection of --experimental-detect-module for
the entrypoint from executeUserEntryPoint() into
Module.prototype._compile() and handle it directly in the
CJS loader so that the errors thrown during compilation *and
execution* during the loading of the entrypoint does not
need to be bubbled all the way up. If the entrypoint doesn't
parse as CJS, and detection is enabled, the CJS loader will
re-load the entrypoint as ESM on the spot asynchronously using
runEntryPointWithESMLoader() and cascadedLoader.import(). This
is fine for the entrypoint because unlike require(ESM) we don't
the namespace of the entrypoint synchronously, and can just
ignore the returned value. In this case process.mainModule is
reset to undefined as they are not available for ESM entrypoints.
3. Supports --experimental-detect-module for require(esm).
PR-URL: https://github.com/nodejs/node/pull/52047
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
This patch adds `require()` support for synchronous ESM graphs under
the flag `--experimental-require-module`
This is based on the the following design aspect of ESM:
- The resolution can be synchronous (up to the host)
- The evaluation of a synchronous graph (without top-level await) is
also synchronous, and, by the time the module graph is instantiated
(before evaluation starts), this is is already known.
If `--experimental-require-module` is enabled, and the ECMAScript
module being loaded by `require()` meets the following requirements:
- Explicitly marked as an ES module with a `"type": "module"` field in
the closest package.json or a `.mjs` extension.
- Fully synchronous (contains no top-level `await`).
`require()` will load the requested module as an ES Module, and return
the module name space object. In this case it is similar to dynamic
`import()` but is run synchronously and returns the name space object
directly.
```mjs
// point.mjs
export function distance(a, b) {
return (b.x - a.x) ** 2 + (b.y - a.y) ** 2;
}
class Point {
constructor(x, y) { this.x = x; this.y = y; }
}
export default Point;
```
```cjs
const required = require('./point.mjs');
// [Module: null prototype] {
// default: [class Point],
// distance: [Function: distance]
// }
console.log(required);
(async () => {
const imported = await import('./point.mjs');
console.log(imported === required); // true
})();
```
If the module being `require()`'d contains top-level `await`, or the
module graph it `import`s contains top-level `await`,
[`ERR_REQUIRE_ASYNC_MODULE`][] will be thrown. In this case, users
should load the asynchronous module using `import()`.
If `--experimental-print-required-tla` is enabled, instead of throwing
`ERR_REQUIRE_ASYNC_MODULE` before evaluation, Node.js will evaluate the
module, try to locate the top-level awaits, and print their location to
help users fix them.
PR-URL: https://github.com/nodejs/node/pull/51977
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Guy Bedford <guybedford@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
The term "native module" dates back to some of the oldest code
in the code base. Within the context of Node.js core it usually
refers to modules that are native to Node.js (e.g. fs, http),
but it can cause confusion for people who don't work on this
part of the code base, as "native module" can also refer to
native addons - which is even the case in some of the API
docs and error messages.
This patch tries to make the usage of these terms more consistent.
Now within the context of Node.js core:
- JavaScript scripts that are built-in to Node.js are now referred
to as "built-in(s)". If they are available as modules,
they can also be referred to as "built-in module(s)".
- Dynamically-linked shared objects that are loaded into
the Node.js processes are referred to as "addons".
We will try to avoid using the term "native modules" because it could
be ambiguous.
Changes in this patch:
File names:
- node_native_module.h -> node_builtins.h,
- node_native_module.cc -> node_builtins.cc
C++ binding names:
- `native_module` -> `builtins`
`node::Environment`:
- `native_modules_without_cache` -> `builtins_without_cache`
- `native_modules_with_cache` -> `builtins_with_cache`
- `native_modules_in_snapshot` -> `builtins_in_cache`
- `native_module_require` -> `builtin_module_require`
`node::EnvSerializeInfo`:
- `native_modules` -> `builtins
`node::native_module::NativeModuleLoader`:
- `native_module` namespace -> `builtins` namespace
- `NativeModuleLoader` -> `BuiltinLoader`
- `NativeModuleRecordMap` -> `BuiltinSourceMap`
- `NativeModuleCacheMap` -> `BuiltinCodeCacheMap`
- `ModuleIds` -> `BuiltinIds`
- `ModuleCategories` -> `BuiltinCategories`
- `LoadBuiltinModuleSource` -> `LoadBuiltinSource`
`loader.js`:
- `NativeModule` -> `BuiltinModule` (the `NativeModule` name used in
`process.moduleLoadList` is kept for compatibility)
And other clarifications in the documentation and comments.
PR-URL: https://github.com/nodejs/node/pull/44135
Fixes: https://github.com/nodejs/node/issues/44036
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Marcel Laverdet