prevent Sentry.init() code from being injected into excluded routes

Author: lobsterkatie

packages/nextjs/src/config/webpack.ts

@@ -1,6 +1,6 @@
 /* eslint-disable max-lines */
 import { getSentryRelease } from '@sentry/node';
-import { arrayify, dropUndefinedKeys, escapeStringForRegex, logger } from '@sentry/utils';
+import { arrayify, dropUndefinedKeys, escapeStringForRegex, logger, stringMatchesSomePattern } from '@sentry/utils';
 import { default as SentryWebpackPlugin } from '@sentry/webpack-plugin';
 import * as chalk from 'chalk';
 import * as fs from 'fs';
@@ -139,7 +139,7 @@ export function constructWebpackConfigFunction(
     // will call the callback which will call `f` which will call `x.y`... and on and on. Theoretically this could also
     // be fixed by using `bind`, but this is way simpler.)
     const origEntryProperty = newConfig.entry;
-    newConfig.entry = async () => addSentryToEntryProperty(origEntryProperty, buildContext);
+    newConfig.entry = async () => addSentryToEntryProperty(origEntryProperty, buildContext, userSentryOptions);
 
     // Enable the Sentry plugin (which uploads source maps to Sentry when not in dev) by default
     if (shouldEnableWebpackPlugin(buildContext, userSentryOptions)) {
@@ -252,6 +252,7 @@ function findTranspilationRules(rules: WebpackModuleRule[] | undefined, projectD
 async function addSentryToEntryProperty(
   currentEntryProperty: WebpackEntryProperty,
   buildContext: BuildContext,
+  userSentryOptions: UserSentryOptions,
 ): Promise<EntryPropertyObject> {
   // The `entry` entry in a webpack config can be a string, array of strings, object, or function. By default, nextjs
   // sets it to an async function which returns the promise of an object of string arrays. Because we don't know whether
@@ -272,7 +273,7 @@ async function addSentryToEntryProperty(
 
   // inject into all entry points which might contain user's code
   for (const entryPointName in newEntryProperty) {
-    if (shouldAddSentryToEntryPoint(entryPointName, isServer)) {
+    if (shouldAddSentryToEntryPoint(entryPointName, isServer, userSentryOptions.excludeServerRoutes)) {
       addFilesToExistingEntryPoint(newEntryProperty, entryPointName, filesToInject);
     }
   }
@@ -381,13 +382,21 @@ function checkWebpackPluginOverrides(
  *
  * @param entryPointName The name of the entry point in question
  * @param isServer Whether or not this function is being called in the context of a server build
+ * @param excludeServerRoutes A list of excluded serverside entrypoints provided by the user
  * @returns `true` if sentry code should be injected, and `false` otherwise
  */
-function shouldAddSentryToEntryPoint(entryPointName: string, isServer: boolean): boolean {
+function shouldAddSentryToEntryPoint(
+  entryPointName: string,
+  isServer: boolean,
+  excludeServerRoutes: Array<string | RegExp> = [],
+): boolean {
   // On the server side, by default we inject the `Sentry.init()` code into every page (with a few exceptions).
   if (isServer) {
     const entryPointRoute = entryPointName.replace(/^pages/, '');
     if (
+      // User-specified pages to skip. (Note: For ease of use, `excludeServerRoutes` is specified in terms of routes,
+      // which don't have the `pages` prefix.)
+      stringMatchesSomePattern(entryPointRoute, excludeServerRoutes, true) ||
       // All non-API pages contain both of these components, and we don't want to inject more than once, so as long as
       // we're doing the individual pages, it's fine to skip these. (Note: Even if a given user doesn't have either or
       // both of these in their `pages/` folder, they'll exist as entrypoints because nextjs will supply default