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>
`v8::Module::IsGraphAsync()` traverses the dependencies to find if they
contain TLA each time. `ModuleWrap.hasAsyncGraph` caches the result
and exposes the property to JS land so that the presence of the property
`module.hasAsyncGraph` can be consistent.
This also allows C++ access of cached `hasAsyncGraph`.
This merges the `intantiateSync`/`instantiate` and
`getNamespaceSync`/`getNamespace` as they are always sync.
PR-URL: https://github.com/nodejs/node/pull/59703
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Otherwise if the ESM happens to be cached separately by the ESM loader
before it gets loaded with `require(esm)` from within an imported
CJS file (which uses a re-invented require() with a couple of quirks,
including a separate cache), it won't be able to load the esm properly
from the cache.
PR-URL: https://github.com/nodejs/node/pull/59679
Refs: https://github.com/nodejs/node/issues/59666
Refs: https://github.com/nodejs/node/issues/52697
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Clarify the names - hasAsyncGraph means either the module or its
dependencies contains top-level await; hasTopLevelAwait means the
module itself contains top-level await. Theoratically the former
can be inferred from iterating over the dependencies but for the
built-in loader it's currently not fully reliable until we eliminate
async linking.
Also remove the hasTopLevelAwait method - we can simply put it
on the module wrap for source text modules right after compilation.
PR-URL: https://github.com/nodejs/node/pull/59675
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
This completes the TODO to compile WASM synchronously and thus
making translation (i.e. compilation + instantiation) synchronous.
PR-URL: https://github.com/nodejs/node/pull/59453
Refs: https://github.com/nodejs/node/issues/55782
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
1. Make sure that the conditions are converted into arrays when
being passed into user hooks.
2. Pass the conditions from user hooks into the ESM resolution
so that it takes effect.
PR-URL: https://github.com/nodejs/node/pull/59011
Fixes: https://github.com/nodejs/node/issues/59003
Reviewed-By: Zeyu "Alex" Yang <himself65@outlook.com>
Reviewed-By: Jacob Smith <jacob@frende.me>
PR-URL: https://github.com/nodejs/node/pull/58521
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: LiviaMedeiros <livia@cirno.name>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Re-evaluating an errored ESM should lead to rejecting
the rejection again - this is also the case when importing
it twice. In the case of retrying with
require after import, just throw the cached error.
Drive-by: add some debug logs.
PR-URL: https://github.com/nodejs/node/pull/58957
Fixes: https://github.com/nodejs/node/issues/58945
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Boolean value to check if an ES Module is the entrypoint of the
current process.
Implements: #57226
Co-authored-by: Antoine du Hamel <duhamelantoine1995@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/57804
Fixes: https://github.com/nodejs/node/issues/57226
Reviewed-By: James M Snell <jasnell@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: Marco Ippolito <marcoippolito54@gmail.com>
- Improve the error message that shows up when there is a race
from doing require(esm) and import(esm) at the same time.
- Improve error message of ERR_REQUIRE_ASYNC_MODULE by showing
parent and target file names, if available.
Drive-by: split the require(tla) tests since we are modifying
the tests already.
PR-URL: https://github.com/nodejs/node/pull/57126
Refs: https://github.com/fisker/prettier-issue-17139
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Co-Authored-By: Carlos Espa <43477095+Ceres6@users.noreply.github.com>
PR-URL: https://github.com/nodejs/node/pull/56499
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
This tracks the asynchronicity in the ModuleWraps when they turn out to
contain TLA after instantiation, and throw the right error
(ERR_REQUIRE_ASYNC_MODULE) when it's required again. It removes
the freezing of ModuleWraps since it's not meaningful to freeze
this when the rest of the module loader is mutable, and we
can record the asynchronicity in the ModuleWrap right after
compilation after we get a V8 upgrade that contains
v8::Module::HasTopLevelAwait() instead of searching through
the module graph repeatedly which can be slow.
PR-URL: https://github.com/nodejs/node/pull/55520
Fixes: https://github.com/nodejs/node/issues/55516
Refs: https://github.com/nodejs/node/issues/52697
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Jacob Smith <jacob@frende.me>
This unflags --experimental-require-module so require(esm) can be
used without the flag. For now, when require() actually encounters
an ESM, it will still emit an experimental warning. To opt out
of the feature, --no-experimental-require-module can be used.
There are some tests specifically testing ERR_REQUIRE_ESM. Some
of them are repurposed to test --no-experimental-require-module.
Some of them are modified to just expect loading require(esm) to
work, when it's appropriate.
PR-URL: https://github.com/nodejs/node/pull/55085
Refs: https://github.com/nodejs/node/issues/52697
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: LiviaMedeiros <livia@cirno.name>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Filip Skokan <panva.ip@gmail.com>
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
This lays the foundation for supporting synchronous hooks proposed
in https://github.com/nodejs/loaders/pull/198 for ESM.
- Corrects and adds several JSDoc comments for internal functions
of the ESM loader, as well as explaining how require() for
import CJS work in the special resolve/load paths. This doesn't
consolidate it with import in require(esm) yet due to caching
differences, which is left as a TODO.
- The moduleProvider passed into ModuleJob is replaced as
moduleOrModulePromise, we call the translators directly in the
ESM loader and verify it right after loading for clarity.
- Reuse a few refactored out helpers for require(esm) in
getModuleJobForRequire().
PR-URL: https://github.com/nodejs/node/pull/54769
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: James M Snell <jasnell@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 commit adds a tracing channel for module loading
through `import()` and `require()`.
Co-Authored-By: Stephen Belanger <admin@stephenbelanger.com>
PR-URL: https://github.com/nodejs/node/pull/44340
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
PR-URL: https://github.com/nodejs/node/pull/52658
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Daniel Lemire <daniel@lemire.me>
This reverts commit 22cb99d073.
PR-URL: https://github.com/nodejs/node/pull/53183
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
PR-URL: https://github.com/nodejs/node/pull/52706
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
Avoid repetitively calling into JS callback from C++ in
`ModuleWrap::Link`. This removes the convoluted callback style of the
internal `ModuleWrap` link step.
PR-URL: https://github.com/nodejs/node/pull/52058
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Previously there is an edge case where submodules loaded by require()
may not be loaded by import() again from different intermediate
edges in the graph. This patch fixes that, added tests, and added
debug logs.
Drive-by: make loader a private field so it doesn't show up in logs.
PR-URL: https://github.com/nodejs/node/pull/52487
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
This patch disallows CJS <-> ESM edges when they come from
require(esm) requested in ESM evalaution.
Drive-by: don't reuse the cache for imported CJS modules to stash
source code of required ESM because the former is also used for
cycle detection.
PR-URL: https://github.com/nodejs/node/pull/52264
Fixes: https://github.com/nodejs/node/issues/52145
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Guy Bedford <guybedford@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
This refactors the code that compiles SourceTextModule for the
built-in ESM loader to use a common routine so that it's easier
to customize cache handling for the ESM loader. In addition
this introduces a common symbol for import.meta and import()
so that we don't need to create additional closures as handlers,
since we can get all the information we need from the V8 callback
already. This should reduce the memory footprint of ESM as well.
PR-URL: https://github.com/nodejs/node/pull/52291
Refs: https://github.com/nodejs/node/issues/47472
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.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>
