Tracking issue: require(esm) #52697

joyeecheung · 2024-04-25T21:25:06Z

Before it's unflagged

Figure out default export interop with transpilers, either adding __esModule to required ESM on our end (module: add __esModule to require()'d ESM #52166), or transpilers update themselves to check the result returned by require():
conditional exports for module, regardless of whether it's loaded by require or import. Something like module which is recognized by Webpack and Rollup would be good (maybe this doesn't need to block unflagging, but should be done before stablization) module: implement the "module-sync" exports condition #54648
Move experimental warning to where require() is actually handling a ESM

Before it is promoted to be stable:

Implement detection module: support ESM detection in the CJS loader #52047
Some marker to customize the default exports returned by require(esm) module: support 'module.exports' interop export name in require(esm) #54563
Support module customization hooks doc: add synchronous hooks proposal loaders#198

Nice-to-haves:

Add API for dumping or inspecting the consolidated CJS and EJS module graph #52180
Provide some mechanism to conditionally and synchronously import modules (or just builtins) from ESM #52599 (fixed in process: add process.getBuiltinModule(id) #52762)
Better documentation on how to publish packages in a post-require-esm era/migration guide: https://github.com/nodejs/package-examples

Bug fixes & changes:

Related features that interoperate with require(esm) and need to be considered when being backported together:

For v22.x backport (see a summary of regression analysis in #55217 (comment))

For v20.x backport: TBD

The text was updated successfully, but these errors were encountered:

GeoffreyBooth · 2024-04-30T19:16:14Z

@nodejs/loaders

jakebailey · 2024-05-07T22:00:30Z

I just wanted to note it here, but it would be super super awesome if (once stable) this were backported to Node 20/22 or even Node 18 if still in support. I'd love to be able to propose a change to switch TypeScript to ESM (given I have it working without breaking CJS consumers), but the time horizon of Node 22 being the oldest supported version is pretty daunting.

It also seems like there is a hacky way using multiple entrypoints that could allow for TS to grab Node's builtins conditionally without #52599/#52762, though none of that is possible without require(ESM), of course.

Even without TypeScript's use case, I think the feature itself is a really important one for the ecosystem. Backporting would really make ESM changeovers a lot less painful.

Andarist · 2024-05-07T22:07:50Z

IIRC from some Twitter threads - there is a plan to backport this once the feature stabilizes.

joyeecheung · 2024-07-11T23:16:42Z

Regarding the conditional exports, @guybedford suggested to implement just the module condition that Rollup and Webpack already recognize. I have a WIP but need to do some testing which involves many combinations of test cases 😵‍💫 but will also do some npm crawling to see if it can be picked up/is in conflict with any existing popular packages.

GeoffreyBooth · 2024-07-11T23:41:11Z

@guybedford suggested to implement just the module condition that Rollup and Webpack already recognize.

The module top level field, or within exports?

Personally I think require-module makes more sense, as it would complement the existing require and import keys that Node supports.

joyeecheung · 2024-08-29T22:54:36Z

Opened PR for "module" in #54648

Personally I think require-module makes more sense, as it would complement the existing require and import keys that Node supports.

If we are starting from scratch, yes, but then the "module" condition has already been adopted by bundlers that support require(esm) in the wild, so it seems better to go along with the existing convention. See https://gist.github.com/sokra/e032a0f17c1721c71cfced6f14516c62

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: #54648 Fixes: #52173 Refs: https://github.com/joyeecheung/test-module-condition Refs: #52697 Reviewed-By: Jacob Smith <[email protected]> Reviewed-By: Jan Krems <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]>

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: #55085 Refs: #52697 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Marco Ippolito <[email protected]> Reviewed-By: Rafael Gonzaga <[email protected]> Reviewed-By: Yagiz Nizipli <[email protected]> Reviewed-By: LiviaMedeiros <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Filip Skokan <[email protected]> Reviewed-By: Michael Dawson <[email protected]> Reviewed-By: Richard Lau <[email protected]>

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: nodejs#54648 Fixes: nodejs#52173 Refs: https://github.com/joyeecheung/test-module-condition Refs: nodejs#52697 Reviewed-By: Jacob Smith <[email protected]> Reviewed-By: Jan Krems <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]>

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: nodejs#55085 Refs: nodejs#52697 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Marco Ippolito <[email protected]> Reviewed-By: Rafael Gonzaga <[email protected]> Reviewed-By: Yagiz Nizipli <[email protected]> Reviewed-By: LiviaMedeiros <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Filip Skokan <[email protected]> Reviewed-By: Michael Dawson <[email protected]> Reviewed-By: Richard Lau <[email protected]>

voxpelli · 2024-10-03T12:53:10Z

Raised a question on Twitter to @joyeecheung on my conclusions in https://github.com/voxpelli/investigation-esm-require where it seems like Node 22.9.0 may unintentionally allow some ESM-files to be loaded even without the flag: https://twitter.com/voxpelli/status/1841818608713826693

Mentioning here for sake of completeness, if deemed a correct observation a proper issue will be created

voxpelli · 2024-10-04T07:46:34Z

The above resulted in a PR to fix it: #55250

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: #54648 Fixes: #52173 Refs: https://github.com/joyeecheung/test-module-condition Refs: #52697 Reviewed-By: Jacob Smith <[email protected]> Reviewed-By: Jan Krems <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]>

targos · 2024-10-05T09:38:54Z

It looks like npm itself triggers the warning:

$ make lint
cd tools/eslint && if [ -x ""/Users/mzasso/git/nodejs/node/node"" ] && [ -e ""/Users/mzasso/git/nodejs/node/node"" ]; then ""/Users/mzasso/git/nodejs/node/node"" /Users/mzasso/git/nodejs/node/./deps/npm/bin/npm-cli.js ci; elif [ -x `command -v node` ] && [ -e `command -v node` ] && [ `command -v node` ]; then `command -v node` /Users/mzasso/git/nodejs/node/./deps/npm/bin/npm-cli.js ci; else echo "No available node, cannot run \"node /Users/mzasso/git/nodejs/node/./deps/npm/bin/npm-cli.js ci\""; exit 1; fi;
npm warn cli npm v10.8.3 does not support Node.js v23.0.0-pre. This version of npm supports the following node versions: `^18.17.0 || >=20.5.0`. You can find the latest version at https://nodejs.org/.
(node:45192) ExperimentalWarning: Support for loading ES Module in require() is an experimental feature and might change at any time
    at emitExperimentalWarning (node:internal/util:269:11)
    at loadESMFromCJS (node:internal/modules/cjs/loader:1388:5)
    at Module._compile (node:internal/modules/cjs/loader:1517:5)
    at Module._extensions..js (node:internal/modules/cjs/loader:1672:16)
    at Module.load (node:internal/modules/cjs/loader:1328:32)
    at Module._load (node:internal/modules/cjs/loader:1138:12)
    at TracingChannel.traceSync (node:diagnostics_channel:315:14)
    at wrapModuleLoad (node:internal/modules/cjs/loader:218:24)
    at Module.require (node:internal/modules/cjs/loader:1350:12)
    at require (node:internal/modules/helpers:138:16)

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joyeecheung · 2024-10-05T20:24:06Z

Yes, because of debug, which I covered in #55217 (comment) and addressed in the last commit of the backport PR. In the last TSC meeting we agreed to silence the warning when require() comes from node_modules on v22 and keep it on v23 to help people notice and update them (with #55241)

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: nodejs#55085 Refs: nodejs#52697 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Marco Ippolito <[email protected]> Reviewed-By: Rafael Gonzaga <[email protected]> Reviewed-By: Yagiz Nizipli <[email protected]> Reviewed-By: LiviaMedeiros <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Filip Skokan <[email protected]> Reviewed-By: Michael Dawson <[email protected]> Reviewed-By: Richard Lau <[email protected]>

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: #52047 Backport-PR-URL: #56927 Reviewed-By: Geoffrey Booth <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Refs: #52697

So that if there are circular dependencies in the synchronous module graph, they could be resolved using the cached jobs. In case linking fails and the error gets caught, reset the cache right after linking. If it succeeds, the caller will cache it again. Otherwise the error bubbles up to users, and since we unset the cache for the unlinkable module the next attempt would still fail. PR-URL: #52868 Backport-PR-URL: #56927 Fixes: #52864 Reviewed-By: Moshe Atlow <[email protected]> Reviewed-By: Vinícius Lourenço Claro Cardoso <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]> Refs: #52697

PR-URL: #53050 Backport-PR-URL: #56927 Reviewed-By: Geoffrey Booth <[email protected]> Reviewed-By: James M Snell <[email protected]> Refs: #52697

Unifies the CJS and ESM source map cache map with SourceMapCacheMap and allows the CJS cache entries to be queried more efficiently with a source url without iteration on an IterableWeakMap. Add a test to verify that the CJS source map cache entry can be reclaimed. PR-URL: #51711 Backport-PR-URL: #56927 Reviewed-By: Joyee Cheung <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Refs: #52697

PR-URL: #52658 Backport-PR-URL: #56927 Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Daniel Lemire <[email protected]> Refs: #52697

This patch: 1. Refactor the routines used to compile and run an embedder entrypoint. In JS land special handling for SEA is done directly in main/embedding.js instead of clobbering the CJS loader. Add warnings to remind users that currently the require() in SEA bundled scripts only supports loading builtins. 2. Don't use the bundled SEA code cache when compiling CJS loaded from disk, since in that case we are certainly not compiling the code bundled into the SEA. Use a is_sea_main flag in CompileFunctionForCJSLoader() (which replaces an unused argument) to pass this into the C++ land - the code cache is still read directly from C++ to avoid the overhead of ArrayBuffer creation. 3. Move SEA loading code into MaybeLoadSingleExecutableApplication() which calls LoadEnvironment() with its own StartExecutionCallback(). This avoids more hidden switches in StartExecution() and make them explicit. Also add some TODOs about how to support ESM in embedded applications. 4. Add more comments PR-URL: #53573 Backport-PR-URL: #56927 Reviewed-By: Geoffrey Booth <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]> Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: James M Snell <[email protected]> Refs: #52697

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: #52166 Backport-PR-URL: #56927 Refs: #52134 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Filip Skokan <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]> Reviewed-By: Guy Bedford <[email protected]> Reviewed-By: Geoffrey Booth <[email protected]> Refs: #52697

PR-URL: #53872 Backport-PR-URL: #56927 Reviewed-By: Geoffrey Booth <[email protected]> Reviewed-By: Paolo Insogna <[email protected]> Reviewed-By: Matteo Collina <[email protected]> Refs: #52697

PR-URL: #53619 Backport-PR-URL: #56927 Reviewed-By: Benjamin Gruenbaum <[email protected]> Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Refs: #52697

It was intended that warnings should only be emitted for an existing package.json without a type. This fixes a confusing warning telling users to update /package.json when there are no package.json on the lookup path at all, like this: [MODULE_TYPELESS_PACKAGE_JSON] Warning: ... parsed as an ES module because module syntax was detected; to avoid the performance penalty of syntax detection, add "type": "module" to /package.json Drive-by: update the warning message to be clear about reparsing and make it clear what's actionable. PR-URL: #54045 Backport-PR-URL: #56927 Reviewed-By: Geoffrey Booth <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Benjamin Gruenbaum <[email protected]> Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: James M Snell <[email protected]> Refs: #52697

PR-URL: #54868 Backport-PR-URL: #56927 Fixes: #54773 Reviewed-By: James M Snell <[email protected]> Reviewed-By: Luigi Pinca <[email protected]> Refs: #52697

The synchronous CJS translator can handle entrypoints now, this can be hit when --import is used, so lift the bogus assertions and added tests. PR-URL: #54592 Backport-PR-URL: #56927 Fixes: #54577 Reviewed-By: James M Snell <[email protected]> Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Refs: #52697

PR-URL: #54980 Backport-PR-URL: #56927 Fixes: #54931 Reviewed-By: Michaël Zasso <[email protected]> Reviewed-By: Marco Ippolito <[email protected]> Reviewed-By: Joyee Cheung <[email protected]> Refs: #52697

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: #54648 Backport-PR-URL: #56927 Fixes: #52173 Refs: https://github.com/joyeecheung/test-module-condition Refs: #52697 Reviewed-By: Jacob Smith <[email protected]> Reviewed-By: Jan Krems <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]>

This lays the foundation for supporting synchronous hooks proposed in nodejs/loaders#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: #54769 Backport-PR-URL: #56927 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Stephen Belanger <[email protected]> Reviewed-By: James M Snell <[email protected]> Refs: #52697

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: #55085 Backport-PR-URL: #56927 Refs: #52697 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Marco Ippolito <[email protected]> Reviewed-By: Rafael Gonzaga <[email protected]> Reviewed-By: Yagiz Nizipli <[email protected]> Reviewed-By: LiviaMedeiros <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Filip Skokan <[email protected]> Reviewed-By: Michael Dawson <[email protected]> Reviewed-By: Richard Lau <[email protected]>

PR-URL: #54563 Backport-PR-URL: #56927 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Joyee Cheung <[email protected]> Refs: #52697

PR-URL: #55199 Backport-PR-URL: #56927 Reviewed-By: Moshe Atlow <[email protected]> Reviewed-By: Guy Bedford <[email protected]> Reviewed-By: Joyee Cheung <[email protected]> Refs: #52697

This is faster and more consistent with other places using the regular expression to detect node_modules. PR-URL: #55243 Backport-PR-URL: #56927 Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Jacob Smith <[email protected]> Reviewed-By: Richard Lau <[email protected]> Reviewed-By: Marco Ippolito <[email protected]> Refs: #52697

For detecting whether `require(esm)` is supported without triggering the experimental warning. PR-URL: #55241 Backport-PR-URL: #56927 Reviewed-By: Richard Lau <[email protected]> Reviewed-By: Matteo Collina <[email protected]> Refs: #52697

This previously compiles a script and run it in a new context to avoid global pollution, which is more complex than necessary and can be too slow for it to be reused in other cases. The new implementation just checks the frames in C++ which is safe from global pollution, faster and simpler. The previous implementation also had a bug when the call site is in a ESM, because ESM have URLs as their script names, which don't start with '/' or '\' and will be skipped. The new implementation removes the skipping to fix it for ESM. PR-URL: #55286 Backport-PR-URL: #56927 Reviewed-By: Yagiz Nizipli <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]> Refs: #52697

Previously we assumed if `--experimental-detect-module` is true, then `--experimental-require-module` is true, which isn't the case, as the two can be enabled/disabled separately. This patch fixes the checks so `--no-experimental-require-module` is still effective when `--experimental-detect-module` is enabled. Drive-by: make the assertion messages more informative and remove obsolete TODO about allowing TLA in entrypoints handled by require(esm). PR-URL: #55250 Backport-PR-URL: #56927 Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Jacob Smith <[email protected]> Reviewed-By: Rafael Gonzaga <[email protected]> Refs: #52697

When emitting the experimental warning for `require(esm)`, include information about the parent module and the module being require()-d to help users locate and update them. PR-URL: #55397 Backport-PR-URL: #56927 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Stephen Belanger <[email protected]> Reviewed-By: Chemi Atlow <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]> Refs: #52697

When a ESM module cannot be loaded by require due to the presence of TLA, its module status would be stopped at kInstantiated. In this case, when it's imported again, we should allow it to be evaluated asynchronously, as it's also a common pattern for users to retry with dynamic import when require fails. PR-URL: #55502 Backport-PR-URL: #56927 Fixes: #55500 Refs: #52697 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Chemi Atlow <[email protected]>

Trim off irrelevant internal stack frames for require(esm) warnings so it's easier to locate where the call comes from when --trace-warnings is used. PR-URL: #55496 Backport-PR-URL: #56927 Reviewed-By: Marco Ippolito <[email protected]> Reviewed-By: Paolo Insogna <[email protected]> Refs: #52697

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: #55520 Backport-PR-URL: #56927 Fixes: #55516 Refs: #52697 Reviewed-By: Paolo Insogna <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Chengzhong Wu <[email protected]> Reviewed-By: Jacob Smith <[email protected]>

As part of the standard experimental feature graduation policy, when we unflagged require(esm) we moved the experimental warning to be emitted when require() is actually used to load ESM, which previously was an error. However, some packages in the ecosystem have already being using try-catch to load require(esm) to e.g. resolve optional dependency, and emitting warning from there instead of throwing directly could break the CLI output. To reduce the disruption for releases, as a compromise, this patch skips the warning if require(esm) comes from node_modules, where users typically don't have much control over the code. This warning will be eventually removed when require(esm) becomes stable. This patch was originally intended for the LTS releases, though it seems there's appetite for it on v23.x as well so it's re-targeted to the main branch. PR-URL: #55960 Backport-PR-URL: #56927 Refs: #55217 Refs: #52697 Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Jacob Smith <[email protected]>

Previously the implemention of require(esm) only converted the rejected promise from module evaluation into an error, but the rejected promise was still treated as a pending unhandled rejection by the promise rejection callback, because the promise is created by V8 internals and we don't get a chance to mark it as handled, so the rejection incorrectly marked as unhandled would still go through unhandled rejection handling (if no global listener is set, the default handling would print a warning and make the Node.js instance exit with 1). This patch fixes it by calling into the JS promise rejection callback to mark the evalaution rejection handled so that it doesn't go through unhandled rejection handling. PR-URL: #56122 Backport-PR-URL: #56927 Fixes: #56115 Reviewed-By: Benjamin Gruenbaum <[email protected]> Reviewed-By: Chemi Atlow <[email protected]> Refs: #52697

require(esm) is relatively stable now and the experimental warning has run its course - it's now more troublesome than useful. This patch changes it to no longer emit a warning unless `--trace-require-module` is explicitly used. The flag supports two modes: - `--trace-require-module=all`: emit warnings for all usages - `--trace-require-module=no-node-modules`: emit warnings for usages that do not come from a `node_modules` folder. PR-URL: #56194 Backport-PR-URL: #56927 Fixes: #55417 Reviewed-By: James M Snell <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Yagiz Nizipli <[email protected]> Reviewed-By: Matteo Collina <[email protected]> Reviewed-By: Geoffrey Booth <[email protected]> Reviewed-By: Marco Ippolito <[email protected]> Reviewed-By: Rafael Gonzaga <[email protected]> Refs: #52697

These features are already removed since v22. There is no point supporting them to work with require(esm) in v20. PR-URL: #56927 Refs: #52697 Reviewed-By: Marco Ippolito <[email protected]>

joyeecheung added module Issues and PRs related to the module subsystem. esm Issues and PRs related to the ECMAScript Modules implementation. labels Apr 25, 2024

RyanCavanaugh mentioned this issue Apr 29, 2024

Default import from an ESM package into a CommonJS project with esModuleInterop is faulty microsoft/TypeScript#58341

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GeoffreyBooth mentioned this issue May 3, 2024

deps: vendor emphasize #52826

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dgozman mentioned this issue Aug 8, 2024

[Feature] Add a way to handle CJS/ESM module hell microsoft/playwright#23662

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joyeecheung mentioned this issue Aug 20, 2024

Session Proposal: module loading customization/optimization and CJS/ESM interoperability openjs-foundation/summit#422

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joyeecheung mentioned this issue Aug 29, 2024

module: implement the "module-sync" exports condition #54648

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This was referenced Sep 19, 2024

Node.js 23 release plan nodejs/Release#1034

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module: unflag --experimental-require-module #55085

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voxpelli mentioned this issue Oct 4, 2024

Bug: no-missing-import doesn't use the require algorithm when TS has CJS moduleResolution? eslint-community/eslint-plugin-n#349

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joyeecheung mentioned this issue Oct 5, 2024

[v22.x] backport unflagging of --experimental-require-module and related fixes/refactorings #55217

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tats-u mentioned this issue Oct 8, 2024

Enable consuming of ES modules in extensions microsoft/vscode#130367

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marco-ippolito pushed a commit that referenced this issue Feb 11, 2025

module: do not set CJS variables for Worker eval

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PR-URL: #53050 Backport-PR-URL: #56927 Reviewed-By: Geoffrey Booth <[email protected]> Reviewed-By: James M Snell <[email protected]> Refs: #52697

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Tracking issue: require(esm) #52697

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Tracking issue: require(esm) #52697

Tracking issue: require(esm) #52697

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