exclude build-time files

packages/nextjs/src/config/webpack.ts

@@ -1,10 +1,11 @@
 /* eslint-disable max-lines */
-import { getSentryRelease } from '@sentry/node';
+import { deepReadDirSync, getSentryRelease } from '@sentry/node';
 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';
 import * as path from 'path';
+import { WebpackPluginInstance } from 'webpack';
 
 import {
   BuildContext,
@@ -100,6 +101,28 @@ export function constructWebpackConfigFunction(
           ],
         });
       }
+
+      // Prevent `@vercel/nft` (which nextjs uses to determine which files are needed when packaging up a lambda) from
+      // including any of our build-time code or dependencies. (Otherwise it'll include files like this one and even the
+      // entirety of rollup and sucrase.)
+      const nftPlugin = newConfig.plugins?.find((plugin: WebpackPluginInstance) => {
+        const proto = Object.getPrototypeOf(plugin) as WebpackPluginInstance;
+        return proto.constructor.name === 'TraceEntryPointsPlugin';
+      }) as WebpackPluginInstance & { excludeFiles: string[] };
+      if (nftPlugin) {
+        const nextjsPackageRoot = path.dirname(require.resolve('@sentry/nextjs'));
+        const nextjsPackageConfigDir = path.join(nextjsPackageRoot, 'config');
+        const excludedNextjsPackageFiles = deepReadDirSync(nextjsPackageConfigDir).map(file =>
+          path.join(nextjsPackageConfigDir, file),
+        );
+
+        nftPlugin.excludeFiles.push(...excludedNextjsPackageFiles);
+      } else {
+        __DEBUG_BUILD__ &&
+          logger.warn(
+            'Unable to exclude Sentry build-time helpers from nft files. Could not find `TraceEntryPointsPlugin`.',
+          );
+      }
     }
 
     // The SDK uses syntax (ES6 and ES6+ features like object spread) which isn't supported by older browsers. For users