esm: add a fallback when importer in not a file

aduh95 · marco-ippolito · commit 86cb697b81dd · 2025-01-24T22:17:37.000+01:00
PR-URL: #55471 Reviewed-By: Jacob Smith <jacob@frende.me> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Jake Yuesong Li <jake.yuesong@gmail.com>
diff --git a/lib/internal/modules/esm/resolve.js b/lib/internal/modules/esm/resolve.js
@@ -236,9 +236,15 @@ const encodedSepRegEx = /%2F|%5C/i;
  */
 function finalizeResolution(resolved, base, preserveSymlinks) {
   if (RegExpPrototypeExec(encodedSepRegEx, resolved.pathname) !== null) {
+    let basePath;
+    try {
+      basePath = fileURLToPath(base);
+    } catch {
+      basePath = base;
+    }
     throw new ERR_INVALID_MODULE_SPECIFIER(
       resolved.pathname, 'must not include encoded "/" or "\\" characters',
-      fileURLToPath(base));
+      basePath);
   }
 
   let path;
@@ -256,14 +262,26 @@ function finalizeResolution(resolved, base, preserveSymlinks) {
 
   // Check for stats.isDirectory()
   if (stats === 1) {
-    throw new ERR_UNSUPPORTED_DIR_IMPORT(path, fileURLToPath(base), String(resolved));
+    let basePath;
+    try {
+      basePath = fileURLToPath(base);
+    } catch {
+      basePath = base;
+    }
+    throw new ERR_UNSUPPORTED_DIR_IMPORT(path, basePath, String(resolved));
   } else if (stats !== 0) {
     // Check for !stats.isFile()
     if (process.env.WATCH_REPORT_DEPENDENCIES && process.send) {
       process.send({ 'watch:require': [path || resolved.pathname] });
     }
+    let basePath;
+    try {
+      basePath = fileURLToPath(base);
+    } catch {
+      basePath = base;
+    }
     throw new ERR_MODULE_NOT_FOUND(
-      path || resolved.pathname, base && fileURLToPath(base), resolved);
+      path || resolved.pathname, basePath, resolved);
   }
 
   if (!preserveSymlinks) {
diff --git a/test/es-module/test-esm-main-lookup.mjs b/test/es-module/test-esm-main-lookup.mjs
@@ -15,6 +15,14 @@ await assert.rejects(import('../fixtures/es-modules/pjson-main'), {
   code: 'ERR_UNSUPPORTED_DIR_IMPORT',
   url: fixtures.fileURL('es-modules/pjson-main').href,
 });
+await assert.rejects(import(`data:text/javascript,import${encodeURIComponent(JSON.stringify(fixtures.fileURL('es-modules/pjson-main')))}`), {
+  code: 'ERR_UNSUPPORTED_DIR_IMPORT',
+  url: fixtures.fileURL('es-modules/pjson-main').href,
+});
+await assert.rejects(import(`data:text/javascript,import${encodeURIComponent(JSON.stringify(fixtures.fileURL('es-modules/does-not-exist')))}`), {
+  code: 'ERR_MODULE_NOT_FOUND',
+  url: fixtures.fileURL('es-modules/does-not-exist').href,
+});
 
 assert.deepStrictEqual(
   { ...await import('../fixtures/es-modules/pjson-main/main.mjs') },
