WIP Make CJS suggestions when file ext is not provided

[juanarbol]

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included

[juanarbol]

This is breaking a test, this one test/message/esm_loader_not_found.mjs

// test/message/esm_loader_not_found.mjs
// Flags:  --experimental-loader i-dont-exist
import '../common/index.mjs';
console.log('This should not be printed');

Script:
$ ./node --experimental-loader i-dont-exist test/message/esm_loader_not_found.mjs

Output:

(node:43614) ExperimentalWarning: The ESM module loader is experimental.
(node:43614) ExperimentalWarning: --experimental-loader is an experimental feature. This feature could change at any time
internal/modules/esm/default_resolve.js:102
    url = moduleWrapResolve(specifier, parentURL);
          ^

Error: Cannot find package 'i-dont-exist' imported from /Users/juanjose/Documents/GitHub/Node/node/
    at Loader.resolve [as _resolve] (internal/modules/esm/default_resolve.js:102:11)
    at Loader.resolve (internal/modules/esm/loader.js:73:33)
    at Loader.getModuleJob (internal/modules/esm/loader.js:147:40)
    at Loader.import (internal/modules/esm/loader.js:131:28)
    at internal/process/esm_loader.js:63:31
    at Object.initializeLoader (internal/process/esm_loader.js:67:5)
    at runMainESM (internal/modules/run_main.js:41:20)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:64:5)
    at internal/main/run_main_module.js:17:47 {
  code: 'ERR_MODULE_NOT_FOUND'
}

No idea why. I'm stuck on this.

[guybedford]

That's correct - ./tools/test.py test/message/esm_loader-not_found.mjs should compare the output to https://github.com/nodejs/node/blob/master/test/message/esm_loader_not_found.out and pass the test.

[juanarbol]

Jm, I get it, but the thing is that test script is returning error, that output is the only error. I mean, make test is not passing.

[guybedford]

Message tests will always provide a diff when there's an error. A stack line might change then the .output file can be updated.

[juanarbol]

Aaaah, you say, it's a diff between .output file and my output?

[BridgeAR]

I like the idea behind this. It does require a test case though.

[juanarbol]

I'm try to write that test

[BridgeAR]

Ping @juanarbol

[juanarbol]

@BridgeAR I'm having a issue here, when I run ./node test/es-modules/this-test.mjs does not work the CJS stuff, but when I change my cd to test/es-modules, and run ../../node this-test.mjs it works, you have any suggestions or something?

[BridgeAR]

@nodejs/modules-active-members PTAL

[bmeck]

I like the error suggestions, but at least per files without an extension this is no longer true per #31021 try using a file like https://github.com/nodejs/node/blob/master/test/fixtures/es-modules/package-type-module/extension.unknown for your test fixture instead

[BridgeAR]

Ping @juanarbol

[juanarbol]

Sorry, the ES Module implementation has changed like a lot, I'll take more time to migrate this to the new implementation, seems harder than before, but with some time this could be done.

[juanarbol]

I'll close this, and spend some time to understand the new loader then open another PR; sorry