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>
Split the `internal/process/esm_loader` file which contains the
singleton cascaded loader:
- The the singleton cascaded loader now directly resides in
`internal/modules/esm/loader`, where the constructor also lives.
This file is the root of most circular dependency of ESM code,
(because components of the loader need the singleton itself),
so this makes the dependency more obvious. Added comments about
loading it lazily to avoid circular dependency.
- The getter to the cascaded loader is also turned into a method
to make the side effect explicit.
- The sequence of `loadESM()` and `handleMainPromise` is now merged
together into `runEntryPointWithESMLoader()` in
`internal/modules/run_main` because this is intended to run entry
points with the ESM loader and not just any module.
- Documents how top-level await is handled.
PR-URL: https://github.com/nodejs/node/pull/51999
Fixes: https://github.com/nodejs/node/issues/42868
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
This patch adds support for using
`vm.constants.USE_MAIN_CONTEXT_DEFAULT_LOADER` as
`importModuleDynamically` in all APIs that take the option
except `vm.SourceTextModule`. This allows users to have a shortcut
to support dynamic import() in the compiled code without missing
the compilation cache if they don't need customization of the
loading process. We emit an experimental warning when the
`import()` is actually handled by the default loader through
this option instead of requiring `--experimental-vm-modules`.
In addition this refactors the documentation for
`importModuleDynamically` and adds a dedicated section for it
with examples.
`vm.SourceTextModule` is not supported in this patch because
it needs additional refactoring to handle `initializeImportMeta`,
which can be done in a follow-up.
PR-URL: https://github.com/nodejs/node/pull/51244
Fixes: https://github.com/nodejs/node/issues/51154
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
This bootstraps ESM loaders in the ShadowRealm with
`ShadowRealm.prototype.importValue` as its entry point and enables
loading ESM and CJS modules in the ShadowRealm. The module is imported
without a parent URL and resolved with the current process's working
directory.
PR-URL: https://github.com/nodejs/node/pull/48655
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Users cannot access any API that can be used to return a module or
module namespace in this callback without --experimental-vm-modules
anyway, so this would eventually lead to a rejection. This patch
rejects in this case with our own error message and use a constant
host-defined option for the rejection, so that scripts with the
same source can still be compiled using the compilation cache
if no `import()` is actually called in the script.
PR-URL: https://github.com/nodejs/node/pull/50137
Refs: https://github.com/nodejs/node/issues/35375
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
The old import assertions proposal has been
renamed to "import attributes" with the follwing major changes:
1. The keyword is now `with` instead of `assert`.
2. Unknown assertions cause an error rather than being ignored,
This commit updates the documentation to encourage folks to use the new
syntax, and add aliases for module customization hooks.
PR-URL: https://github.com/nodejs/node/pull/50140
Fixes: https://github.com/nodejs/node/issues/50134
Refs: 159c82c5e6
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
This makes it possile to hit the in-isolate compilation cache when
host-defined options are not necessary.
PR-URL: https://github.com/nodejs/node/pull/49950
Refs: https://github.com/nodejs/node/issues/35375
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Previously when managing the importModuleDynamically callback of
vm.compileFunction(), we use an ID number as the host defined option
and maintain a per-Environment ID -> CompiledFnEntry map to retain
the top-level referrer function returned by vm.compileFunction() in
order to pass it back to the callback, but it would leak because with
how we used v8::Persistent to maintain this reference, V8 would not
be able to understand the cycle and would just think that the
CompiledFnEntry was supposed to live forever. We made an attempt
to make that reference known to V8 by making the CompiledFnEntry weak
and using a private symbol to make CompiledFnEntry strongly
references the top-level referrer function in
https://github.com/nodejs/node/pull/46785, but that turned out to be
unsound, because the there's no guarantee that the top-level function
must be alive while import() can still be initiated from that
function, since V8 could discard the top-level function and only keep
inner functions alive, so relying on the top-level function to keep
the CompiledFnEntry alive could result in use-after-free which caused
a revert of that fix.
With this patch we use a symbol in the host defined options instead of
a number, because with the stage-3 symbol-as-weakmap-keys proposal
we could directly use that symbol to keep the referrer alive using a
WeakMap. As a bonus this also keeps the other kinds of referrers
alive as long as import() can still be initiated from that
Script/Module, so this also fixes the long-standing crash caused by
vm.Script being GC'ed too early when its importModuleDynamically
callback still needs it.
PR-URL: https://github.com/nodejs/node/pull/48510
Refs: https://github.com/nodejs/node/issues/44211
Refs: https://github.com/nodejs/node/issues/42080
Refs: https://github.com/nodejs/node/issues/47096
Refs: https://github.com/nodejs/node/issues/43205
Refs: https://github.com/nodejs/node/issues/38695
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Follows @giltayar's proposed API:
> `register` can pass any data it wants to the loader, which will be
passed to the exported `initialize` function of the loader.
Additionally, if the user of `register` wants to communicate with the
loader, it can just create a `MessageChannel` and pass the port to the
loader as data.
The `register` API is now:
```ts
interface Options {
parentUrl?: string;
data?: any;
transferList?: any[];
}
function register(loader: string, parentUrl?: string): any;
function register(loader: string, options?: Options): any;
```
This API is backwards compatible with the old one (new arguments are
optional and at the end) and allows for passing data into the new
`initialize` hook. If this hook returns data it is passed back to
`register`:
```ts
function initialize(data: any): Promise<any>;
```
**NOTE**: Currently there is no mechanism for a loader to exchange
ownership of something back to the caller.
Refs: https://github.com/nodejs/loaders/issues/147
PR-URL: https://github.com/nodejs/node/pull/48842
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Major functional changes:
- Allow `import()` to work within loaders that require other loaders,
- Unflag the use of `Module.register`.
A new interface `Customizations` has been created in order to unify
`ModuleLoader` (previously `DefaultModuleLoader`), `Hooks` and
`CustomizedModuleLoader` all of which now implement it:
```ts
interface LoadResult {
format: ModuleFormat;
source: ModuleSource;
}
interface ResolveResult {
format: string;
url: URL['href'];
}
interface Customizations {
allowImportMetaResolve: boolean;
load(url: string, context: object): Promise<LoadResult>
resolve(
originalSpecifier:
string, parentURL: string,
importAssertions: Record<string, string>
): Promise<ResolveResult>
resolveSync(
originalSpecifier:
string, parentURL: string,
importAssertions: Record<string, string>
) ResolveResult;
register(specifier: string, parentUrl: string): any;
forceLoadHooks(): void;
importMetaInitialize(meta, context, loader): void;
}
```
The `ModuleLoader` class now has `setCustomizations` which takes an
object of this shape and delegates its responsibilities to this object
if present.
Note that two properties `allowImportMetaResolve` and `resolveSync`
exist now as a mechanism for `import.meta.resolve` – since `Hooks`
does not implement `resolveSync` other loaders cannot use
`import.meta.resolve`; `allowImportMetaResolve` is a way of checking
for that case instead of invoking `resolveSync` and erroring.
Fixes https://github.com/nodejs/node/issues/48515
Closes https://github.com/nodejs/node/pull/48439
PR-URL: https://github.com/nodejs/node/pull/48559
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
PR-URL: https://github.com/nodejs/node/pull/46826
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
This avoids initializing arrays that we never use, and simplifies the
implementation overall.
PR-URL: https://github.com/nodejs/node/pull/48296
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Use the default loader as the cascaded loader in the loader worker.
Otherwise we spawn loader workers in the loader workers indefinitely.
PR-URL: https://github.com/nodejs/node/pull/47620
Fixes: https://github.com/nodejs/node/issues/47566
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Jacob Smith <jacob@frende.me>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
This moves the following utils into modules/esm/utils.js:
- Code related to default conditions
- The callbackMap (which is now created in the module instead of
hanging off the module_wrap binding, since the C++ land
does not need it).
- Per-isolate module callbacks
These are self-contained code that can be included into the
built-in snapshot.
PR-URL: https://github.com/nodejs/node/pull/45849
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
