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>
So that we can use it to handle code caching in a central place.
Drive-by: use per-isolate persistent strings for the parameters
and mark GetHostDefinedOptions() since it's only used in one
compilation unit
PR-URL: https://github.com/nodejs/node/pull/52016
Refs: https://github.com/nodejs/node/issues/47472
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Previously, the `require()` function exposed to the embedded SEA code
was calling the internal `require()` function if the module name
belonged to the list of public core modules but the internal `require()`
function does not support loading modules with the "node:" prefix, so
this change forwards the calls to another `require()` function that
supports this.
Fixes: https://github.com/nodejs/single-executable/issues/69
Signed-off-by: Darshan Sen <raisinten@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/47779
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Since SEA is very similar in principle to embedding functionality,
it makes sense to share code paths where possible. This commit does
so and addresses a `TODO` while doing so.
It also adds a utility to directly run CJS code to the embedder
startup callback, which comes in handy for this purpose.
Finally, this commit is breaking because it aligns the behavior
of `require()`ing internal modules; previously, embedders could
use the `require` function that they received to do so.
(If this is not considered breaking because accessing internals
is not covered by the API, then this would need ABI compatibility
patches for becoming fully non-breaking.)
PR-URL: https://github.com/nodejs/node/pull/46825
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Minwoo Jung <nodecorelab@gmail.com>
