perf: drop babel to reduce the server bundle size

.changeset/new-wombats-crash.md

@@ -0,0 +1,5 @@
+---
+"@opennextjs/aws": patch
+---
+
+perf: drop `babel` to reduce the server bundle size

packages/open-next/src/build/createServerBundle.ts

@@ -21,15 +21,7 @@ import {
 import * as buildHelper from "./helper.js";
 import { installDependencies } from "./installDeps.js";
 import { type CodePatcher, applyCodePatches } from "./patch/codePatcher.js";
-import {
-  patchBackgroundRevalidation,
-  patchEnvVars,
-  patchFetchCacheForISR,
-  patchFetchCacheSetMissingWaitUntil,
-  patchNextServer,
-  patchUnstableCacheForISR,
-  patchUseCacheForISR,
-} from "./patch/patches/index.js";
+import * as patches from "./patch/patches/index.js";
 
 interface CodeCustomization {
   // These patches are meant to apply on user and next generated code
@@ -207,13 +199,14 @@ async function generateBundle(
   const additionalCodePatches = codeCustomization?.additionalCodePatches ?? [];
 
   await applyCodePatches(options, tracedFiles, manifests, [
-    patchFetchCacheSetMissingWaitUntil,
-    patchFetchCacheForISR,
-    patchUnstableCacheForISR,
-    patchNextServer,
-    patchEnvVars,
-    patchBackgroundRevalidation,
-    patchUseCacheForISR,
+    patches.patchFetchCacheSetMissingWaitUntil,
+    patches.patchFetchCacheForISR,
+    patches.patchUnstableCacheForISR,
+    patches.patchNextServer,
+    patches.patchEnvVars,
+    patches.patchBackgroundRevalidation,
+    patches.patchUseCacheForISR,
+    patches.patchDropBabel,
     ...additionalCodePatches,
   ]);
 

packages/open-next/src/build/patch/patches/dropBabel.ts

@@ -0,0 +1,88 @@
+/**
+ * Patches to avoid pulling babel (~4MB).
+ *
+ * Details:
+ * - empty `NextServer#runMiddleware` and `NextServer#runEdgeFunction` that are not used
+ * - drop `next/dist/server/node-environment-extensions/error-inspect.js`
+ */
+
+import { getCrossPlatformPathRegex } from "utils/regex.js";
+import { patchCode } from "../astCodePatcher.js";
+import type { CodePatcher } from "../codePatcher.js";
+
+export const patchDropBabel: CodePatcher = {
+  name: "patch-drop-babel",
+  patches: [
+    // Empty the body of `NextServer#runMiddleware`
+    {
+      field: {
+        pathFilter: getCrossPlatformPathRegex(
+          String.raw`/next/dist/server/next-server\.js$`,
+          {
+            escape: false,
+          },
+        ),
+        contentFilter: /runMiddleware\(/,
+        patchCode: async ({ code }) =>
+          patchCode(code, createEmptyBodyRule("runMiddleware")),
+      },
+    },
+    // Empty the body of `NextServer#runEdgeFunction`
+    {
+      field: {
+        pathFilter: getCrossPlatformPathRegex(
+          String.raw`/next/dist/server/next-server\.js$`,
+          {
+            escape: false,
+          },
+        ),
+        contentFilter: /runEdgeFunction\(/,
+        patchCode: async ({ code }) =>
+          patchCode(code, createEmptyBodyRule("runEdgeFunction")),
+      },
+    },
+    // Drop `error-inspect` that pulls babel
+    {
+      field: {
+        pathFilter: getCrossPlatformPathRegex(
+          String.raw`next/dist/server/node-environment\.js$`,
+          {
+            escape: false,
+          },
+        ),
+        contentFilter: /error-inspect/,
+        patchCode: async ({ code }) => patchCode(code, errorInspectRule),
+      },
+    },
+  ],
+};
+
+/**
+ * Swaps the body for a throwing implementation
+ *
+ * @param methodName The name of the method
+ * @returns A rule to replace the body with a `throw`
+ */
+export function createEmptyBodyRule(methodName: string) {
+  return `
+rule:
+  pattern:
+    selector: method_definition
+    context: "class { async ${methodName}($$$PARAMS) { $$$_ } }"
+fix: |-
+  async ${methodName}($$$PARAMS) {
+    throw new Error("${methodName} should not be called with OpenNext");
+  }
+`;
+}
+
+/**
+ * Drops `require("./node-environment-extensions/error-inspect");`
+ */
+export const errorInspectRule = `
+rule:
+  pattern: require("./node-environment-extensions/error-inspect");
+fix: |-
+  // Removed by OpenNext
+  // require("./node-environment-extensions/error-inspect");
+`;

packages/open-next/src/build/patch/patches/index.ts

@@ -7,3 +7,4 @@ export {
 } from "./patchFetchCacheISR.js";
 export { patchFetchCacheSetMissingWaitUntil } from "./patchFetchCacheWaitUntil.js";
 export { patchBackgroundRevalidation } from "./patchBackgroundRevalidation.js";
+export { patchDropBabel } from "./dropBabel.js";

packages/tests-unit/tests/build/patch/patches/dropBabel.test.ts

@@ -0,0 +1,194 @@
+import { patchCode } from "@opennextjs/aws/build/patch/astCodePatcher.js";
+import {
+  createEmptyBodyRule,
+  errorInspectRule,
+} from "@opennextjs/aws/build/patch/patches/dropBabel.js";
+import { describe, expect, test } from "vitest";
+
+describe("babel-drop", () => {
+  test("Drop body", () => {
+    const code = `
+class NextNodeServer extends _baseserver.default {
+    constructor(options){
+        // Initialize super class
+        super(options);
+        this.handleNextImageRequest = async (req, res, parsedUrl) => { /* ... */ };
+    }
+    async handleUpgrade() {
+    // The web server does not support web sockets, it's only used for HMR in
+    // development.
+    }
+    getEnabledDirectories(dev) {
+        const dir = dev ? this.dir : this.serverDistDir;
+        return {
+            app: (0, _findpagesdir.findDir)(dir, "app") ? true : false,
+            pages: (0, _findpagesdir.findDir)(dir, "pages") ? true : false
+        };
+    }
+    /**
+   * This method gets all middleware matchers and execute them when the request
+   * matches. It will make sure that each middleware exists and is compiled and
+   * ready to be invoked. The development server will decorate it to add warns
+   * and errors with rich traces.
+   */ async runMiddleware(params) {
+        if (process.env.NEXT_MINIMAL) {
+            throw new Error('invariant: runMiddleware should not be called in minimal mode');
+        }
+        // Middleware is skipped for on-demand revalidate requests
+        if ((0, _apiutils.checkIsOnDemandRevalidate)(params.request, this.renderOpts.previewProps).isOnDemandRevalidate) {
+            return {
+                response: new Response(null, {
+                    headers: {
+                        'x-middleware-next': '1'
+                    }
+                })
+            };
+        }
+      // ...
+    }
+    async runEdgeFunction(params) {
+        if (process.env.NEXT_MINIMAL) {
+            throw new Error('Middleware is not supported in minimal mode.');
+        }
+        let edgeInfo;
+        const { query, page, match } = params;
+        if (!match) await this.ensureEdgeFunction({
+            page,
+            appPaths: params.appPaths,
+            url: params.req.url
+        });
+        // ...
+    }
+    // ...
+}`;
+
+    expect(
+      patchCode(code, createEmptyBodyRule("runMiddleware")),
+    ).toMatchInlineSnapshot(`
+      "class NextNodeServer extends _baseserver.default {
+          constructor(options){
+              // Initialize super class
+              super(options);
+              this.handleNextImageRequest = async (req, res, parsedUrl) => { /* ... */ };
+          }
+          async handleUpgrade() {
+          // The web server does not support web sockets, it's only used for HMR in
+          // development.
+          }
+          getEnabledDirectories(dev) {
+              const dir = dev ? this.dir : this.serverDistDir;
+              return {
+                  app: (0, _findpagesdir.findDir)(dir, "app") ? true : false,
+                  pages: (0, _findpagesdir.findDir)(dir, "pages") ? true : false
+              };
+          }
+          /**
+         * This method gets all middleware matchers and execute them when the request
+         * matches. It will make sure that each middleware exists and is compiled and
+         * ready to be invoked. The development server will decorate it to add warns
+         * and errors with rich traces.
+         */ async runMiddleware(params) {
+        throw new Error("runMiddleware should not be called with OpenNext");
+      }
+          async runEdgeFunction(params) {
+              if (process.env.NEXT_MINIMAL) {
+                  throw new Error('Middleware is not supported in minimal mode.');
+              }
+              let edgeInfo;
+              const { query, page, match } = params;
+              if (!match) await this.ensureEdgeFunction({
+                  page,
+                  appPaths: params.appPaths,
+                  url: params.req.url
+              });
+              // ...
+          }
+          // ...
+      }"
+    `);
+
+    expect(
+      patchCode(code, createEmptyBodyRule("runEdgeFunction")),
+    ).toMatchInlineSnapshot(`
+      "class NextNodeServer extends _baseserver.default {
+          constructor(options){
+              // Initialize super class
+              super(options);
+              this.handleNextImageRequest = async (req, res, parsedUrl) => { /* ... */ };
+          }
+          async handleUpgrade() {
+          // The web server does not support web sockets, it's only used for HMR in
+          // development.
+          }
+          getEnabledDirectories(dev) {
+              const dir = dev ? this.dir : this.serverDistDir;
+              return {
+                  app: (0, _findpagesdir.findDir)(dir, "app") ? true : false,
+                  pages: (0, _findpagesdir.findDir)(dir, "pages") ? true : false
+              };
+          }
+          /**
+         * This method gets all middleware matchers and execute them when the request
+         * matches. It will make sure that each middleware exists and is compiled and
+         * ready to be invoked. The development server will decorate it to add warns
+         * and errors with rich traces.
+         */ async runMiddleware(params) {
+              if (process.env.NEXT_MINIMAL) {
+                  throw new Error('invariant: runMiddleware should not be called in minimal mode');
+              }
+              // Middleware is skipped for on-demand revalidate requests
+              if ((0, _apiutils.checkIsOnDemandRevalidate)(params.request, this.renderOpts.previewProps).isOnDemandRevalidate) {
+                  return {
+                      response: new Response(null, {
+                          headers: {
+                              'x-middleware-next': '1'
+                          }
+                      })
+                  };
+              }
+            // ...
+          }
+          async runEdgeFunction(params) {
+        throw new Error("runEdgeFunction should not be called with OpenNext");
+      }
+          // ...
+      }"
+    `);
+  });
+
+  test("Error Inspect", () => {
+    const code = `
+// This file should be imported before any others. It sets up the environment
+// for later imports to work properly.
+"use strict";
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+require("./node-environment-baseline");
+require("./node-environment-extensions/error-inspect");
+require("./node-environment-extensions/random");
+require("./node-environment-extensions/date");
+require("./node-environment-extensions/web-crypto");
+require("./node-environment-extensions/node-crypto");
+//# sourceMappingURL=node-environment.js.map
+}`;
+
+    expect(patchCode(code, errorInspectRule)).toMatchInlineSnapshot(`
+      "// This file should be imported before any others. It sets up the environment
+      // for later imports to work properly.
+      "use strict";
+      Object.defineProperty(exports, "__esModule", {
+          value: true
+      });
+      require("./node-environment-baseline");
+      // Removed by OpenNext
+      // require("./node-environment-extensions/error-inspect");
+      require("./node-environment-extensions/random");
+      require("./node-environment-extensions/date");
+      require("./node-environment-extensions/web-crypto");
+      require("./node-environment-extensions/node-crypto");
+      //# sourceMappingURL=node-environment.js.map
+      }"
+    `);
+  });
+});