esm: import.meta.resolve exact module not found errors should return

Author: guybedford

lib/internal/errors.js

@@ -195,6 +195,11 @@ function lazyUtilColors() {
   utilColors ??= require('internal/util/colors');
   return utilColors;
 }
+let url;
+function lazyUrl() {
+  url ??= require('internal/url');
+  return url;
+}
 
 let buffer;
 function lazyBuffer() {
@@ -1450,7 +1455,11 @@ E('ERR_MISSING_ARGS',
     return `${msg} must be specified`;
   }, TypeError);
 E('ERR_MISSING_OPTION', '%s is required', TypeError);
-E('ERR_MODULE_NOT_FOUND', (path, base, type = 'package') => {
+E('ERR_MODULE_NOT_FOUND', function(path, base, type = 'package') {
+  if (type === 'module') {
+    const { pathToFileURL } = lazyUrl();
+    this.url = pathToFileURL(path).href;
+  }
   return `Cannot find ${type} '${path}' imported from ${base}`;
 }, Error);
 E('ERR_MULTIPLE_CALLBACK', 'Callback called multiple times', Error);

lib/internal/modules/esm/initialize_import_meta.js

@@ -12,18 +12,20 @@ const experimentalImportMetaResolve = getOptionValue('--experimental-import-meta
 function createImportMetaResolve(defaultParentURL, loader) {
   return function resolve(specifier, parentURL = defaultParentURL) {
     let url;
-
     try {
       ({ url } = loader.resolveSync(specifier, parentURL));
+      return url;
     } catch (error) {
-      if (error?.code === 'ERR_UNSUPPORTED_DIR_IMPORT') {
-        ({ url } = error);
-      } else {
-        throw error;
+      switch (error?.code) {
+        case 'ERR_UNSUPPORTED_DIR_IMPORT':
+        case 'ERR_MODULE_NOT_FOUND':
+          ({ url } = error);
+          if (url) {
+            return url;
+          }
       }
+      throw error;
     }
-
-    return url;
   };
 }
 

test/es-module/test-esm-import-meta-resolve.mjs

@@ -9,8 +9,12 @@ const fixtures = dirname.slice(0, dirname.lastIndexOf('/', dirname.length - 2) +
 
 assert.strictEqual(import.meta.resolve('./test-esm-import-meta.mjs'),
                    dirname + 'test-esm-import-meta.mjs');
+const notFound = import.meta.resolve('./notfound.mjs');
+assert.strictEqual(new URL(notFound).href, new URL('./notfound.mjs', import.meta.url).href);
+const noExtension = import.meta.resolve('./asset');
+assert.strictEqual(new URL(noExtension).href, new URL('./asset', import.meta.url).href);
 try {
-  import.meta.resolve('./notfound.mjs');
+  import.meta.resolve('does-not-exist');
   assert.fail();
 } catch (e) {
   assert.strictEqual(e.code, 'ERR_MODULE_NOT_FOUND');