ESM resolution and loading is now always synchronous from a
non-loader-hook thread. If no asynchrnous loader hooks are
registered, the resolution/loading is entirely synchronous.
If asynchronous loader hooks are registered, these would be
synchronous on the non-loader-hook thread, and asynchronous
on the loader hook thread.
This avoids several races caused by async/sync loading sharing
the same cache. In particular, asynchronous loader hooks
now works with `require(esm)` - previously it tends to break
due to races.
In addition, when an asynchronous loader hook
returns a promise that never settles, the main thread no longer
silently exits with exit code 13, leaving the code below
any module loading calls silently ignored without being executed.
Instead, it now throws ERR_ASYNC_LOADER_REQUEST_NEVER_SETTLED
which can be caught and handled by the main thread. If the module
request comes from `import()`, the never-settling promise is
now relayed to the result returned by `import()`.
Drive-by: when annotating the error about importing undetectable
named exports from CommonJS, it now no longer reload the source
code of the CommonJS module, and instead reuses format information
cached when the module was loaded for linking.
PR-URL: https://github.com/nodejs/node/pull/60380
Fixes: https://github.com/nodejs/node/issues/59666
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Jacob Smith <jacob@frende.me>
- This updates the comments that assume loader hooks must be async
- Differentiate the sync/async loader hook paths in naming
`#customizations` is now `#asyncLoaderHooks` to make it clear
it's from the async APIs.
- Differentiate the paths running on the loader hook thread
(affects the loading of async other loader hooks and are async)
v.s. paths on the main thread calling out to code on the loader
hook thread (do not handle loading of other async loader hooks, and
can be sync by blocking).
- `Hooks` is now `AsyncLoaderHooksOnLoaderHookWorker`
- `CustomizedModuleLoader` is now
`AsyncLoaderHooksProxiedToLoaderHookWorker` and moved into
`lib/internal/modules/esm/hooks.js` as it implements the same
interface as `AsyncLoaderHooksOnLoaderHookWorker`
- `HooksProxy` is now `AsyncLoaderHookWorker`
- Adjust the JSDoc accordingly
- Clarify the "loader worker" as the "async loader hook worker"
i.e. when there's no _async_ loader hook registered, there won't
be this worker, to avoid the misconception that this worker
is spawned unconditionally.
- The code run on the loader hook worker to process
`--experimental-loader` is moved into
`lib/internal/modules/esm/worker.js` for clarity.
- The initialization configuration `forceDefaultLoader` is split
into `shouldSpawnLoaderHookWorker` and `shouldPreloadModules`
as those can be separate.
- `--experimental-vm-modules` is now processed during pre-execution
and no longer part of the initialization of the built-in ESM
loader, as it only exposes the vm APIs of ESM, and is unrelated
to built-in ESM loading.
PR-URL: https://github.com/nodejs/node/pull/60278
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.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>
doc: update ESM hook examples
esm: fix unsafe primordial
doc: fix ESM example linting
esm: allow source of type ArrayBuffer
doc: update ESM hook changelog to include resolve format
esm: allow all ArrayBuffers and TypedArrays for load hook source
doc: tidy code & API docs
doc: convert ESM source table header from Title Case to Sentence case
doc: add detailed explanation for getPackageType
esm: add caveat that ESMLoader::import() must NOT be renamed
esm: tidy code declaration of getFormat protocolHandlers
doc: correct ESM doc link (bad conflict resolution)
doc: update ESM hook limitation for CJS
esm: tweak preload description
doc: update ESM getPackageType() example explanation
PR-URL: https://github.com/nodejs/node/pull/37468
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Guy Bedford <guybedford@gmail.com>
Reviewed-By: Bradley Farias <bradley.meck@gmail.com>
Reviewed-By: Geoffrey Booth <webmaster@geoffreybooth.com>
This completely refactors the `expectsError` behavior: so far it's
almost identical to `assert.throws(fn, object)` in case it was used
with a function as first argument. It had a magical property check
that allowed to verify a functions `type` in case `type` was passed
used in the validation object. This pattern is now completely removed
and `assert.throws()` should be used instead.
The main intent for `common.expectsError()` is to verify error cases
for callback based APIs. This is now more flexible by accepting all
validation possibilites that `assert.throws()` accepts as well. No
magical properties exist anymore. This reduces surprising behavior
for developers who are not used to the Node.js core code base.
This has the side effect that `common` is used significantly less
frequent.
PR-URL: https://github.com/nodejs/node/pull/31092
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
ERR_INVALID_ARG_TYPE is the most common error used throughout the
code base. This improves the error message by providing more details
to the user and by indicating more precisely which values are allowed
ones and which ones are not.
It adds the actual input to the error message in case it's a primitive.
If it's a class instance, it'll print the class name instead of
"object" and "falsy" or similar entries are not named "type" anymore.
PR-URL: https://github.com/nodejs/node/pull/29675
Reviewed-By: Rich Trott <rtrott@gmail.com>
This makes a effort to make sure all of these errors will actually
also show the received input.
On top of that it refactors a few tests for better maintainability.
It will also change the returned type to always be a simple typeof
instead of special handling null.
PR-URL: https://github.com/nodejs/node/pull/19445
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Antoine du Hamel