fix(nuxt): Windows file:// for import-in-the-middle hook and isAbsolute for C:\ (#23653)

- [x] tests added if needed
- [x] yarn lint passes
- [ ] no related issue, auto-link is fine

Windows fix for Nuxt dev on Node 24.

On Windows `npm run dev` was failing with
`ERR_UNSUPPORTED_ESM_URL_SCHEME` / `Received protocol 'c:'` because
`.nuxt/dev/index.mjs` generated `import 'C:\...'` instead of
`file:///C:/...`. Same `isExternal` check in `rollup.module.config.mjs`
treated `C:\` as external and broke the build.

Changed `addServerConfig.ts` (and the solidstart copy) to emit
`pathToFileURL(...).href` and fixed `isExternal` to use `isAbsolute()`
so Windows absolute paths work. Also handles POSIX fine.

Verified with `yarn nx run @sentry/nuxt:build:dev` -> now passes, and
`pathToFileURL` gives `file:///C:/...` on Windows.

Closes #XXXX

---------

Co-authored-by: Sigrid <32902192+s1gr1d@users.noreply.github.com>

Author: halillusion

packages/nuxt/rollup.module.config.mjs

@@ -1,5 +1,5 @@
 import { readdirSync } from 'node:fs';
-import { join } from 'node:path';
+import { isAbsolute, join } from 'node:path';
 import esbuild from 'rollup-plugin-esbuild';
 
 // The Nuxt module ships two kinds of output that live side by side in `build/module`:
@@ -11,7 +11,7 @@ import esbuild from 'rollup-plugin-esbuild';
 
 // Anything that isn't a relative path is provided by the consuming app or Node at runtime
 // (this covers `@sentry/*`, `nuxt/app`, `#imports`, node builtins), so it stays external.
-const isExternal = id => !id.startsWith('.') && !id.startsWith('/') && !id.startsWith('\0');
+const isExternal = id => !id.startsWith('.') && !isAbsolute(id) && !id.startsWith('\0');
 
 const transpile = esbuild({
   target: 'es2020',

packages/nuxt/src/vite/addServerConfig.ts

@@ -1,4 +1,5 @@
 import { existsSync } from 'node:fs';
+import { basename } from 'node:path';
 import { pathToFileURL } from 'node:url';
 import { addTemplate, createResolver } from '@nuxt/kit';
 import type { Nuxt } from '@nuxt/schema';
@@ -20,6 +21,7 @@ import {
   SENTRY_WRAPPED_FUNCTIONS,
   SERVER_CONFIG_FILENAME,
   toImportSpecifier,
+  toResolvablePath,
 } from './utils';
 
 /** Path of the generated dev-mode config file, relative to the Nuxt build directory. */
@@ -31,7 +33,7 @@ export const DEV_SERVER_CONFIG_PATH = `dev/${SERVER_CONFIG_FILENAME}.mjs`;
  * In dev-mode, Nitro v3 has no server bundle to emit into, so Node loads the server config file as it is written.
  */
 export function addDevServerConfigFile(nuxt: Nuxt, serverConfigFile: string): void {
-  const configPath = createResolver(nuxt.options.rootDir).resolve(`/${serverConfigFile}`);
+  const configPath = createResolver(nuxt.options.rootDir).resolve(serverConfigFile);
   const importSpecifier = toImportSpecifier(
     nuxt.options.rootDir,
     path.join(nuxt.options.buildDir, DEV_SERVER_CONFIG_PATH),
@@ -59,6 +61,15 @@ export function addDevServerConfigFile(nuxt: Nuxt, serverConfigFile: string): vo
       ].join('\n'),
   });
 }
+const CONFIG_EXTENSIONS = ['.ts', '.js', '.mjs', '.cjs', '.mts', '.cts'];
+
+function isServerConfigFile(sourcePath: string, resolvedPath: string): boolean {
+  if (sourcePath === resolvedPath) {
+    return true;
+  }
+  const name = basename(sourcePath);
+  return name === SERVER_CONFIG_FILENAME || CONFIG_EXTENSIONS.some(ext => name === `${SERVER_CONFIG_FILENAME}${ext}`);
+}
 
 /**
  *  Adds the `sentry.server.config.ts` file as `sentry.server.config.mjs` to the `.output` directory to be able to reference this file in the node --import option.
@@ -157,7 +168,7 @@ export function addDynamicImportEntryFileWrapper(
 
   nitro.options.rollupConfig.plugins.push(
     wrapEntryWithDynamicImport({
-      resolvedSentryConfigPath: createResolver(nitro.options.rootDir).resolve(`/${serverConfigFile}`),
+      resolvedSentryConfigPath: createResolver(nitro.options.rootDir).resolve(serverConfigFile),
       experimental_entrypointWrappedFunctions: moduleOptions.experimental_entrypointWrappedFunctions,
     }),
   );
@@ -173,7 +184,7 @@ function injectServerConfigPlugin(nitro: Nitro, serverConfigFile: string, isDebu
     name: 'rollup-plugin-inject-sentry-server-config',
 
     buildStart() {
-      const configPath = createResolver(nitro.options.rootDir).resolve(`/${serverConfigFile}`);
+      const configPath = createResolver(nitro.options.rootDir).resolve(serverConfigFile);
 
       if (!existsSync(configPath)) {
         if (isDebug) {
@@ -193,7 +204,7 @@ function injectServerConfigPlugin(nitro: Nitro, serverConfigFile: string, isDebu
     resolveId(source) {
       if (source.startsWith(filePrefix)) {
         const originalFilePath = source.replace(filePrefix, '');
-        const configPath = createResolver(nitro.options.rootDir).resolve(`/${originalFilePath}`);
+        const configPath = createResolver(nitro.options.rootDir).resolve(originalFilePath);
 
         return { id: configPath };
       }
@@ -206,8 +217,10 @@ function injectServerConfigPlugin(nitro: Nitro, serverConfigFile: string, isDebu
  * A Rollup plugin which wraps the server entry with a dynamic `import()`. This makes it possible to initialize Sentry first
  * by using a regular `import` and load the server after that.
  * This also works with serverless `handler` functions, as it re-exports the `handler`.
+ *
+ * Only exported for testing.
  */
-function wrapEntryWithDynamicImport({
+export function wrapEntryWithDynamicImport({
   resolvedSentryConfigPath,
   experimental_entrypointWrappedFunctions,
   debug,
@@ -225,12 +238,24 @@ function wrapEntryWithDynamicImport({
   return {
     name: 'sentry-wrap-entry-with-dynamic-import',
     async resolveId(source, importer, options) {
-      if (source.includes(`/${SERVER_CONFIG_FILENAME}`)) {
-        return { id: source, moduleSideEffects: true };
+      // `load()` emits `file://` specifiers because Node's ESM loader rejects bare Windows paths,
+      // but Rollup's resolver only understands filesystem paths.
+      const resolvable = toResolvablePath(source);
+      if (!resolvable) {
+        return null;
       }
+      const { path: normalizedSource, wasFileUrl } = resolvable;
 
-      if (options.isEntry && source.includes('.mjs') && !source.includes(`.mjs${SENTRY_WRAPPED_ENTRY}`)) {
-        const resolution = await this.resolve(source, importer, options);
+      if (isServerConfigFile(normalizedSource, resolvedSentryConfigPath)) {
+        return { id: normalizedSource, moduleSideEffects: true };
+      }
+
+      if (
+        options.isEntry &&
+        normalizedSource.includes('.mjs') &&
+        !normalizedSource.includes(`.mjs${SENTRY_WRAPPED_ENTRY}`)
+      ) {
+        const resolution = await this.resolve(normalizedSource, importer, options);
 
         // If it cannot be resolved or is external, just return it so that Rollup can display an error
         if (!resolution || resolution?.external) return resolution;
@@ -254,24 +279,36 @@ function wrapEntryWithDynamicImport({
               )
               .concat(QUERY_END_INDICATOR)}`;
       }
+
+      // Pass isEntry:false to avoid re-entering the isEntry branch and double-wrapping
+      // (normalizedSource strips the SENTRY_WRAPPED_ENTRY query suffix).
+      if (wasFileUrl) {
+        const resolved = await this.resolve(normalizedSource, importer, { ...options, isEntry: false });
+        if (resolved) return resolved;
+        return { id: normalizedSource };
+      }
+
       return null;
     },
     load(id: string) {
       if (id.includes(`.mjs${SENTRY_WRAPPED_ENTRY}`)) {
         const entryId = removeSentryQueryFromPath(id).slice(resolutionIdPrefix.length);
+        const entryIdUrl = pathToFileURL(entryId).href;
+        const configUrl = pathToFileURL(resolvedSentryConfigPath).href;
 
+        // Use entryIdUrl so Node's runtime ESM loader receives file:// on Windows; Rollup normalizes it in resolveId.
         // Mostly useful for serverless `handler` functions
         const reExportedFunctions =
           id.includes(SENTRY_WRAPPED_FUNCTIONS) || id.includes(SENTRY_REEXPORTED_FUNCTIONS)
-            ? constructFunctionReExport(id, entryId)
+            ? constructFunctionReExport(id, entryIdUrl)
             : '';
 
         return (
           // Regular `import` of the Sentry config
-          `import ${JSON.stringify(resolvedSentryConfigPath)};\n` +
+          `import ${JSON.stringify(configUrl)};\n` +
           // Dynamic `import()` for the previous, actual entry point.
           // `import()` can be used for any code that should be run after the hooks are registered (https://nodejs.org/api/module.html#enabling)
-          `import(${JSON.stringify(entryId)});\n` +
+          `import(${JSON.stringify(entryIdUrl)});\n` +
           `${reExportedFunctions}\n`
         );
       }

packages/nuxt/src/vite/utils.ts

@@ -2,6 +2,7 @@ import type { Nuxt } from '@nuxt/schema';
 import { consoleSandbox } from '@sentry/core';
 import * as fs from 'fs';
 import * as path from 'path';
+import { fileURLToPath } from 'node:url';
 import type { SentryNuxtModuleOptions } from '../common/types';
 import { resolvePath } from '@nuxt/kit';
 
@@ -199,6 +200,31 @@ export function constructFunctionReExport(pathWithQuery: string, entryId: string
     );
 }
 
+/**
+ * `load()` emits `file://` specifiers because Node's ESM loader rejects bare Windows
+ * paths (`ERR_UNSUPPORTED_ESM_URL_SCHEME`), but Rollup's resolver only understands
+ * filesystem paths. Returns `undefined` for a malformed `file://` URL.
+ *
+ * Only exported for testing.
+ */
+export function toResolvablePath(source: string): { path: string; wasFileUrl: boolean } | undefined {
+  if (!source.startsWith('file://')) {
+    return { path: source, wasFileUrl: false };
+  }
+  if (source === 'file://' || source === 'file:///') {
+    return undefined;
+  }
+  try {
+    const filePath = fileURLToPath(source);
+    if (!filePath || filePath === '/' || filePath === '\\') {
+      return undefined;
+    }
+    return { path: filePath, wasFileUrl: true };
+  } catch {
+    return undefined;
+  }
+}
+
 /**
  * Sets up alias to work around OpenTelemetry's incomplete ESM imports.
  * https://github.com/getsentry/sentry-javascript/issues/15204

packages/nuxt/test/vite/addServerConfig.test.ts

@@ -1,7 +1,116 @@
 import type { Nuxt } from '@nuxt/schema';
+import { fileURLToPath, pathToFileURL } from 'node:url';
 import * as path from 'path';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
-import { addDevServerConfigFile, DEV_SERVER_CONFIG_PATH } from '../../src/vite/addServerConfig';
+import {
+  addDevServerConfigFile,
+  DEV_SERVER_CONFIG_PATH,
+  wrapEntryWithDynamicImport,
+} from '../../src/vite/addServerConfig';
+import {
+  QUERY_END_INDICATOR,
+  SENTRY_REEXPORTED_FUNCTIONS,
+  SENTRY_WRAPPED_ENTRY,
+  toResolvablePath,
+} from '../../src/vite/utils';
+
+const configPath = '/project/sentry.server.config.ts';
+const entryPath = '/project/.nuxt/entry.mjs';
+
+describe('toResolvablePath', () => {
+  it('passes through non-file specifiers', () => {
+    expect(toResolvablePath('./module')).toEqual({ path: './module', wasFileUrl: false });
+    expect(toResolvablePath(configPath)).toEqual({ path: configPath, wasFileUrl: false });
+  });
+
+  it('converts file:// URLs to filesystem paths', () => {
+    const url = pathToFileURL(entryPath).href;
+    expect(toResolvablePath(url)).toEqual({ path: fileURLToPath(url), wasFileUrl: true });
+  });
+
+  it('returns undefined for malformed file:// URLs', () => {
+    expect(toResolvablePath('file://')).toBeUndefined();
+    expect(toResolvablePath('file:///')).toBeUndefined();
+    expect(toResolvablePath('file://%E0%A4%A')).toBeUndefined();
+  });
+});
+
+describe('wrapEntryWithDynamicImport', () => {
+  const plugin = wrapEntryWithDynamicImport({
+    resolvedSentryConfigPath: configPath,
+    experimental_entrypointWrappedFunctions: ['handler'],
+  }) as unknown as {
+    resolveId: (source: string, importer: string | undefined, options: { isEntry?: boolean }) => Promise<unknown>;
+    load: (id: string) => string | null;
+  };
+  const { resolveId, load } = plugin;
+
+  it('emits file:// URLs from load() so Node resolves them on Windows', () => {
+    const code = load.call({}, `\0raw${entryPath}${SENTRY_WRAPPED_ENTRY}${QUERY_END_INDICATOR}`);
+
+    expect(code).toContain(`import ${JSON.stringify(pathToFileURL(configPath).href)}`);
+    expect(code).toContain(`import(${JSON.stringify(pathToFileURL(entryPath).href)})`);
+    expect(code).not.toContain(`import ${JSON.stringify(configPath)}`);
+  });
+
+  it('uses file:// URLs for re-exported functions', () => {
+    const id = `\0raw${entryPath}${SENTRY_WRAPPED_ENTRY}${SENTRY_REEXPORTED_FUNCTIONS}handler${QUERY_END_INDICATOR}`;
+    const code = load.call({}, id);
+
+    expect(code).toContain(`export { handler } from ${JSON.stringify(pathToFileURL(entryPath).href)}`);
+  });
+
+  it('resolves a file:// config URL to a filesystem path with moduleSideEffects', async () => {
+    const source = pathToFileURL(configPath).href;
+    const result = await resolveId.call({ resolve: vi.fn(), load: vi.fn() }, source, undefined, { isEntry: false });
+
+    expect(result).toEqual({ id: fileURLToPath(source), moduleSideEffects: true });
+  });
+
+  it('resolves a plain config path without converting it', async () => {
+    const result = await resolveId.call({ resolve: vi.fn(), load: vi.fn() }, configPath, undefined, { isEntry: false });
+
+    expect(result).toEqual({ id: configPath, moduleSideEffects: true });
+  });
+
+  it('does not mark backup or test config files as the Sentry server config', async () => {
+    const backupPath = '/project/sentry.server.config.backup.ts';
+    const result = await resolveId.call({ resolve: vi.fn(), load: vi.fn() }, backupPath, undefined, { isEntry: false });
+
+    expect(result).toBeNull();
+  });
+
+  it('resolves file:// entry specifiers without re-entering the entry branch', async () => {
+    const source = pathToFileURL(entryPath).href;
+    const fakeResolve = vi.fn(async () => ({ id: 'resolved-id', external: false }));
+    const result = await resolveId.call({ resolve: fakeResolve, load: vi.fn() }, source, undefined, { isEntry: false });
+
+    expect(fakeResolve).toHaveBeenCalledWith(
+      fileURLToPath(source),
+      undefined,
+      expect.objectContaining({ isEntry: false }),
+    );
+    expect(result).toEqual({ id: 'resolved-id', external: false });
+  });
+
+  it('returns null for malformed file:// URLs', async () => {
+    const result = await resolveId.call({ resolve: vi.fn(), load: vi.fn() }, 'file://', undefined, { isEntry: false });
+
+    expect(result).toBeNull();
+  });
+
+  it('wraps the entry with the dynamic-import query suffix', async () => {
+    const fakeResolve = vi.fn(async () => ({ id: entryPath, external: false }));
+    const fakeLoad = vi.fn(async () => ({ exportedBindings: { '.': ['handler'] }, moduleSideEffects: false }));
+    const result = await resolveId.call({ resolve: fakeResolve, load: fakeLoad }, entryPath, undefined, {
+      isEntry: true,
+    });
+
+    expect(result).toContain(SENTRY_WRAPPED_ENTRY);
+    expect(result).toContain('?sentry-query-wrapped-functions=handler');
+    expect(result?.startsWith('\0raw')).toBe(true);
+  });
+});
 
 const addTemplateMock = vi.hoisted(() => vi.fn());
 
@@ -40,7 +149,7 @@ describe('addDevServerConfigFile', () => {
   });
 
   it('imports the user config as a file URL so Node can load it directly', () => {
-    expect(generate(APP_CONFIG)).toContain(`await import("file://${APP_CONFIG}")`);
+    expect(generate(APP_CONFIG)).toContain(`await import(${JSON.stringify(pathToFileURL(APP_CONFIG).href)})`);
   });
 
   it('sets the dev flag before importing the config', () => {
@@ -64,7 +173,7 @@ describe('addDevServerConfigFile', () => {
 
   describe('when the config comes from a layer outside the project root', () => {
     it('imports the config from the layer it belongs to', () => {
-      expect(generate(LAYER_CONFIG)).toContain(`await import("file://${LAYER_CONFIG}")`);
+      expect(generate(LAYER_CONFIG)).toContain(`await import(${JSON.stringify(pathToFileURL(LAYER_CONFIG).href)})`);
     });
 
     it('keeps the preload path relative to the project root', () => {