module: fix require of imports with package map

[lazerg]

With --experimental-package-map, Module._resolveFilename sent every non-relative request to the package map, # specifiers included. The map has no entry for them, so require('#x') threw MODULE_NOT_FOUND before the package.json "imports" lookup could run. This skips the map for # requests, which matches the documented require() algorithm and what the ESM resolver already does.

Fixes: #66562

[nodejs-github-bot]

Review requested:

• @nodejs/loaders

[github-actions]

Caution

AgentScan found account activity patterns that may be consistent with automation. This is a heuristic, not proof that this pull request was opened by an agent or violates policy. AI-assisted contributions are permitted, but automated tooling must not open pull requests without advance approval, and contributors must personally understand, test, verify, and take responsibility for every submitted change. See the AgentScan analysis, AI use policy, and automation policy for additional context.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.43%. Comparing base (1bcf30b) to head (8ceb94d).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #66565      +/-   ##
==========================================
- Coverage   92.77%   90.43%   -2.34%     
==========================================
  Files         422      791     +369     
  Lines      193590   276517   +82927     
  Branches    29859    53088   +23229     
==========================================
+ Hits       179597   250070   +70473     
- Misses      13664    16846    +3182     
- Partials      329     9601    +9272     

Files with missing lines	Coverage Δ
lib/internal/modules/cjs/loader.js	97.99% <100.00%> (+19.19%)	⬆️

... and 501 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[aduh95]

nit

Suggested change

	const { status, stdout, stderr } = spawnSync(process.execPath, [
	'--no-warnings',
	'--experimental-package-map', packageMapPath,
	'-e',
	`const root = require('#root'); console.log(root.default);`,
	], {
	cwd: fixtures.path('package-map/root'),
	encoding: 'utf8',
	});
	assert.strictEqual(stderr, '');
	assert.match(stdout, /root-package/);
	assert.strictEqual(status, 0, stderr);
	spawnSyncAndAssert(process.execPath, [
	'--no-warnings',
	'--experimental-package-map', packageMapPath,
	'-e',
	`const root = require('#root'); console.log(root.default);`,
	], {
	cwd: fixtures.path('package-map/root'),
	encoding: 'utf8',
	}, {
	stderr: '',
	stdout: /root-package/,
	});

[lazerg]

Done in 8ceb94d, thanks.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/78235/