loader: enforce path normalization before lookup

Author: arcanis

lib/internal/modules/package_map.js

@@ -140,6 +140,8 @@ class PackageMap {
    * @returns {string|null}
    */
   #getKeyForPath(filePath) {
+    filePath = pathResolve(filePath);
+
     const cached = this.#pathToKeyCache.get(filePath);
     if (cached !== undefined) { return cached; }
 

test/parallel/test-require-package-map.js

@@ -79,6 +79,24 @@ describe('CJS: --experimental-package-map', { concurrency: !process.env.TEST_PAR
       assert.match(stdout, /dep-b using dep-a-value/);
       assert.strictEqual(status, 0, stderr);
     });
+
+    it('resolves from createRequire() paths with mixed separators', {
+      skip: !common.isWindows && 'mixed path separators only need normalization on Windows',
+    }, () => {
+      const { status, stdout, stderr } = spawnSync(process.execPath, [
+        '--no-warnings',
+        '--experimental-package-map', packageMapPath,
+        '-e',
+        `const { createRequire } = require('node:module'); const req = createRequire(process.cwd() + '/index.js'); const dep = req('dep-a'); console.log(dep.default);`,
+      ], {
+        cwd: fixtures.path('package-map/root'),
+        encoding: 'utf8',
+      });
+
+      assert.strictEqual(stderr, '');
+      assert.match(stdout, /dep-a-value/);
+      assert.strictEqual(status, 0, stderr);
+    });
   });
 
   describe('resolution boundaries', () => {