chore(nextjs): Clean up and add to config tests (getsentry#4414)

Some small fixes to comments, some cleaner unpacking of variables, and two added tests pulled out of an upcoming PR to keep it focused on its original goal. No behavior changes.

Author: lobsterkatie

packages/nextjs/src/config/webpack.ts

@@ -116,13 +116,13 @@ async function addSentryToEntryProperty(
   // we know is that it won't have gotten *simpler* in form, so we only need to worry about the object and function
   // options. See https://webpack.js.org/configuration/entry-context/#entry.
 
+  const { isServer, dir: projectDir, dev: isDev, config: userNextConfig } = buildContext;
+
   const newEntryProperty =
     typeof currentEntryProperty === 'function' ? await currentEntryProperty() : { ...currentEntryProperty };
 
   // `sentry.server.config.js` or `sentry.client.config.js` (or their TS equivalents)
-  const userConfigFile = buildContext.isServer
-    ? getUserConfigFile(buildContext.dir, 'server')
-    : getUserConfigFile(buildContext.dir, 'client');
+  const userConfigFile = isServer ? getUserConfigFile(projectDir, 'server') : getUserConfigFile(projectDir, 'client');
 
   // we need to turn the filename into a path so webpack can find it
   const filesToInject = [`./${userConfigFile}`];
@@ -131,12 +131,12 @@ async function addSentryToEntryProperty(
   // server SDK's default `RewriteFrames` instance (which needs it at runtime). Doesn't work when using the dev server
   // because it somehow tricks the file watcher into thinking that compilation itself is a file change, triggering an
   // infinite recompiling loop. (This should be fine because we don't upload sourcemaps in dev in any case.)
-  if (buildContext.isServer && !buildContext.dev) {
+  if (isServer && !isDev) {
     const rewriteFramesHelper = path.resolve(
       fs.mkdtempSync(path.resolve(os.tmpdir(), 'sentry-')),
       'rewriteFramesHelper.js',
     );
-    fs.writeFileSync(rewriteFramesHelper, `global.__rewriteFramesDistDir__ = '${buildContext.config.distDir}';\n`);
+    fs.writeFileSync(rewriteFramesHelper, `global.__rewriteFramesDistDir__ = '${userNextConfig.distDir}';\n`);
     // stick our helper file ahead of the user's config file so the value is in the global namespace *before*
     // `Sentry.init()` is called
     filesToInject.unshift(rewriteFramesHelper);
@@ -269,13 +269,13 @@ export function getWebpackPluginOptions(
   buildContext: BuildContext,
   userPluginOptions: Partial<SentryWebpackPluginOptions>,
 ): SentryWebpackPluginOptions {
-  const { isServer, dir: projectDir, buildId, dev: isDev, config: nextConfig, webpack } = buildContext;
-  const distDir = nextConfig.distDir ?? '.next'; // `.next` is the default directory
+  const { buildId, isServer, webpack, config: userNextConfig, dev: isDev, dir: projectDir } = buildContext;
+  const distDir = userNextConfig.distDir ?? '.next'; // `.next` is the default directory
 
   const isWebpack5 = webpack.version.startsWith('5');
-  const isServerless = nextConfig.target === 'experimental-serverless-trace';
+  const isServerless = userNextConfig.target === 'experimental-serverless-trace';
   const hasSentryProperties = fs.existsSync(path.resolve(projectDir, 'sentry.properties'));
-  const urlPrefix = nextConfig.basePath ? `~${nextConfig.basePath}/_next` : '~/_next';
+  const urlPrefix = userNextConfig.basePath ? `~${userNextConfig.basePath}/_next` : '~/_next';
 
   const serverInclude = isServerless
     ? [{ paths: [`${distDir}/serverless/`], urlPrefix: `${urlPrefix}/serverless` }]

packages/nextjs/test/config.test.ts

@@ -315,11 +315,11 @@ describe('webpack config', () => {
 
       expect(finalWebpackConfig.entry).toEqual(
         expect.objectContaining({
-          // original entry point value is a string
+          // original entrypoint value is a string
           // (was 'private-next-pages/api/dogs/[name].js')
           'pages/api/dogs/[name]': [rewriteFramesHelper, serverConfigFilePath, 'private-next-pages/api/dogs/[name].js'],
 
-          // original entry point value is a string array
+          // original entrypoint value is a string array
           // (was ['./node_modules/smellOVision/index.js', 'private-next-pages/_app.js'])
           'pages/_app': [
             rewriteFramesHelper,
@@ -328,14 +328,14 @@ describe('webpack config', () => {
             'private-next-pages/_app.js',
           ],
 
-          // original entry point value is an object containing a string `import` value
-          // (`import` was 'private-next-pages/api/simulator/dogStats/[name].js')
+          // original entrypoint value is an object containing a string `import` value
+          // (was { import: 'private-next-pages/api/simulator/dogStats/[name].js' })
           'pages/api/simulator/dogStats/[name]': {
             import: [rewriteFramesHelper, serverConfigFilePath, 'private-next-pages/api/simulator/dogStats/[name].js'],
           },
 
-          // original entry point value is an object containing a string array `import` value
-          // (`import` was ['./node_modules/dogPoints/converter.js', 'private-next-pages/api/simulator/leaderboard.js'])
+          // original entrypoint value is an object containing a string array `import` value
+          // (was { import: ['./node_modules/dogPoints/converter.js', 'private-next-pages/api/simulator/leaderboard.js'] })
           'pages/api/simulator/leaderboard': {
             import: [
               rewriteFramesHelper,
@@ -345,16 +345,64 @@ describe('webpack config', () => {
             ],
           },
 
-          // original entry point value is an object containg properties besides `import`
-          // (`dependOn` remains untouched)
+          // original entrypoint value is an object containg properties besides `import`
+          // (was { import: 'private-next-pages/api/tricks/[trickName].js', dependOn: 'treats', })
           'pages/api/tricks/[trickName]': {
             import: [rewriteFramesHelper, serverConfigFilePath, 'private-next-pages/api/tricks/[trickName].js'],
-            dependOn: 'treats',
+            dependOn: 'treats', // untouched
           },
         }),
       );
     });
 
+    it('injects user config file into `_app` in both server and client bundles', async () => {
+      const finalServerWebpackConfig = await materializeFinalWebpackConfig({
+        userNextConfig,
+        incomingWebpackConfig: serverWebpackConfig,
+        incomingWebpackBuildContext: serverBuildContext,
+      });
+      const finalClientWebpackConfig = await materializeFinalWebpackConfig({
+        userNextConfig,
+        incomingWebpackConfig: clientWebpackConfig,
+        incomingWebpackBuildContext: clientBuildContext,
+      });
+
+      expect(finalServerWebpackConfig.entry).toEqual(
+        expect.objectContaining({
+          'pages/_app': expect.arrayContaining([serverConfigFilePath]),
+        }),
+      );
+      expect(finalClientWebpackConfig.entry).toEqual(
+        expect.objectContaining({
+          'pages/_app': expect.arrayContaining([clientConfigFilePath]),
+        }),
+      );
+    });
+
+    it('injects user config file into API routes', async () => {
+      const finalWebpackConfig = await materializeFinalWebpackConfig({
+        userNextConfig,
+        incomingWebpackConfig: serverWebpackConfig,
+        incomingWebpackBuildContext: serverBuildContext,
+      });
+
+      expect(finalWebpackConfig.entry).toEqual(
+        expect.objectContaining({
+          'pages/api/simulator/dogStats/[name]': {
+            import: expect.arrayContaining([serverConfigFilePath]),
+          },
+
+          'pages/api/simulator/leaderboard': {
+            import: expect.arrayContaining([serverConfigFilePath]),
+          },
+
+          'pages/api/tricks/[trickName]': expect.objectContaining({
+            import: expect.arrayContaining([serverConfigFilePath]),
+          }),
+        }),
+      );
+    });
+
     it('does not inject anything into non-_app, non-API routes', async () => {
       const finalWebpackConfig = await materializeFinalWebpackConfig({
         userNextConfig,