fix(nuxt): Add @sentry/nuxt as external in Rollup (#16407)

The Sentry Nuxt SDK emits the Sentry config file during the Rollup
build. Users add this file to their application which includes an import
from `@sentry/nuxt` and the init function. This file is then added as an
`.mjs` file in the build output.

However, when building the application, this `.mjs` file included a
bunch of OpenTelemetry imports and not only the init code as every
dependency from `@sentry/nuxt` was traced back and bundled into the
build output.

By adding `@sentry/nuxt` as external, the `.mjs` file really only
contains the content like in the `.ts` file.

**Could** fix
#15204

---------

Co-authored-by: Andrei Borza <andrei.borza@sentry.io>

Author: s1gr1d

packages/nuxt/src/vite/addServerConfig.ts

@@ -8,6 +8,7 @@ import type { SentryNuxtModuleOptions } from '../common/types';
 import {
   constructFunctionReExport,
   constructWrappedFunctionExportQuery,
+  getExternalOptionsWithSentryNuxt,
   getFilenameFromNodeStartCommand,
   QUERY_END_INDICATOR,
   removeSentryQueryFromPath,
@@ -130,6 +131,13 @@ function injectServerConfigPlugin(nitro: Nitro, serverConfigFile: string, debug?
   return {
     name: 'rollup-plugin-inject-sentry-server-config',
 
+    options(opts) {
+      return {
+        ...opts,
+        external: getExternalOptionsWithSentryNuxt(opts.external),
+      };
+    },
+
     buildStart() {
       const configPath = createResolver(nitro.options.srcDir).resolve(`/${serverConfigFile}`);
 

packages/nuxt/src/vite/utils.ts

@@ -2,6 +2,7 @@ import { consoleSandbox } from '@sentry/core';
 import * as fs from 'fs';
 import type { Nuxt } from 'nuxt/schema';
 import * as path from 'path';
+import type { ExternalOption } from 'rollup';
 
 /**
  *  Find the default SDK init file for the given type (client or server).
@@ -72,6 +73,35 @@ export function removeSentryQueryFromPath(url: string): string {
   return url.replace(regex, '');
 }
 
+/**
+ *  Add @sentry/nuxt to the external options of the Rollup configuration to prevent Rollup bundling all dependencies
+ *  that would result in adding imports from OpenTelemetry libraries etc. to the server build.
+ */
+export function getExternalOptionsWithSentryNuxt(previousExternal: ExternalOption | undefined): ExternalOption {
+  const sentryNuxt = /^@sentry\/nuxt$/;
+  let external: ExternalOption;
+
+  if (typeof previousExternal === 'function') {
+    external = new Proxy(previousExternal, {
+      apply(target, thisArg, args: [string, string | undefined, boolean]) {
+        const [source] = args;
+        if (sentryNuxt.test(source)) {
+          return true;
+        }
+        return Reflect.apply(target, thisArg, args);
+      },
+    });
+  } else if (Array.isArray(previousExternal)) {
+    external = [sentryNuxt, ...previousExternal];
+  } else if (previousExternal) {
+    external = [sentryNuxt, previousExternal];
+  } else {
+    external = sentryNuxt;
+  }
+
+  return external;
+}
+
 /**
  * Extracts and sanitizes function re-export and function wrap query parameters from a query string.
  * If it is a default export, it is not considered for re-exporting.

packages/nuxt/test/vite/utils.test.ts

@@ -6,6 +6,7 @@ import {
   constructWrappedFunctionExportQuery,
   extractFunctionReexportQueryParameters,
   findDefaultSdkInitFile,
+  getExternalOptionsWithSentryNuxt,
   getFilenameFromNodeStartCommand,
   QUERY_END_INDICATOR,
   removeSentryQueryFromPath,
@@ -366,3 +367,60 @@ export { foo_sentryWrapped as foo };
     expect(result).toBe('');
   });
 });
+
+describe('getExternalOptionsWithSentryNuxt', () => {
+  it('should return sentryExternals when previousExternal is undefined', () => {
+    const result = getExternalOptionsWithSentryNuxt(undefined);
+    expect(result).toEqual(/^@sentry\/nuxt$/);
+  });
+
+  it('should merge sentryExternals with array previousExternal', () => {
+    const previousExternal = [/vue/, 'react'];
+    const result = getExternalOptionsWithSentryNuxt(previousExternal);
+    expect(result).toEqual([/^@sentry\/nuxt$/, /vue/, 'react']);
+  });
+
+  it('should create array with sentryExternals and non-array previousExternal', () => {
+    const previousExternal = 'vue';
+    const result = getExternalOptionsWithSentryNuxt(previousExternal);
+    expect(result).toEqual([/^@sentry\/nuxt$/, 'vue']);
+  });
+
+  it('should create a proxy when previousExternal is a function', () => {
+    const mockExternalFn = vi.fn().mockReturnValue(false);
+    const result = getExternalOptionsWithSentryNuxt(mockExternalFn);
+
+    expect(typeof result).toBe('function');
+    expect(result).toBeInstanceOf(Function);
+  });
+
+  it('should return true from proxied function when source is @sentry/nuxt', () => {
+    const mockExternalFn = vi.fn().mockReturnValue(false);
+    const result = getExternalOptionsWithSentryNuxt(mockExternalFn);
+
+    // @ts-expect-error - result is a function
+    const output = result('@sentry/nuxt', undefined, false);
+    expect(output).toBe(true);
+    expect(mockExternalFn).not.toHaveBeenCalled();
+  });
+
+  it('should return false from proxied function and call function when source just includes @sentry/nuxt', () => {
+    const mockExternalFn = vi.fn().mockReturnValue(false);
+    const result = getExternalOptionsWithSentryNuxt(mockExternalFn);
+
+    // @ts-expect-error - result is a function
+    const output = result('@sentry/nuxt/dist/index.js', undefined, false);
+    expect(output).toBe(false);
+    expect(mockExternalFn).toHaveBeenCalledWith('@sentry/nuxt/dist/index.js', undefined, false);
+  });
+
+  it('should call original function when source does not include @sentry/nuxt', () => {
+    const mockExternalFn = vi.fn().mockReturnValue(false);
+    const result = getExternalOptionsWithSentryNuxt(mockExternalFn);
+
+    // @ts-expect-error - result is a function
+    const output = result('vue', undefined, false);
+    expect(output).toBe(false);
+    expect(mockExternalFn).toHaveBeenCalledWith('vue', undefined, false);
+  });
+});