perf: reduce the amount of code converted to AST

.changeset/eleven-pumas-film.md

@@ -0,0 +1,5 @@
+---
+"@opennextjs/cloudflare": patch
+---
+
+perf: reduce CPU and memory usage by limiting code to AST parsing

packages/cloudflare/package.json

@@ -76,7 +76,6 @@
     "@opennextjs/aws": "https://pkg.pr.new/@opennextjs/aws@727",
     "enquirer": "^2.4.1",
     "glob": "catalog:",
-    "ts-morph": "catalog:",
     "yaml": "^2.7.0"
   },
   "peerDependencies": {

packages/cloudflare/src/cli/build/bundle-server.ts

@@ -4,14 +4,16 @@ import path from "node:path";
 import { fileURLToPath } from "node:url";
 
 import { type BuildOptions, getPackagePath } from "@opennextjs/aws/build/helper.js";
-import { getCrossPlatformPathRegex } from "@opennextjs/aws/utils/regex.js";
-import { build, Plugin } from "esbuild";
+import { build } from "esbuild";
 
 import { patchVercelOgLibrary } from "./patches/ast/patch-vercel-og-library.js";
 import { patchWebpackRuntime } from "./patches/ast/webpack-runtime.js";
 import * as patches from "./patches/index.js";
+import { ContentUpdater } from "./patches/plugins/content-updater.js";
+import { patchLoadInstrumentation } from "./patches/plugins/load-instrumentation.js";
 import { handleOptionalDependencies } from "./patches/plugins/optional-deps.js";
 import { fixRequire } from "./patches/plugins/require.js";
+import { shimRequireHook } from "./patches/plugins/require-hook.js";
 import { inlineRequirePagePlugin } from "./patches/plugins/require-page.js";
 import { setWranglerExternal } from "./patches/plugins/wrangler-external.js";
 import { normalizePath, patchCodeWithValidations } from "./utils/index.js";
@@ -58,6 +60,8 @@ export async function bundleServer(buildOpts: BuildOptions): Promise<void> {
   const openNextServer = path.join(outputPath, packagePath, `index.mjs`);
   const openNextServerBundle = path.join(outputPath, packagePath, `handler.mjs`);
 
+  const updater = new ContentUpdater();
+
   const result = await build({
     entryPoints: [openNextServer],
     bundle: true,
@@ -77,11 +81,14 @@ export async function bundleServer(buildOpts: BuildOptions): Promise<void> {
     // - ESBuild `node` platform: https://esbuild.github.io/api/#platform
     conditions: [],
     plugins: [
-      createFixRequiresESBuildPlugin(buildOpts),
-      inlineRequirePagePlugin(buildOpts),
+      shimRequireHook(buildOpts),
+      inlineRequirePagePlugin(updater, buildOpts),
       setWranglerExternal(),
-      fixRequire(),
+      fixRequire(updater),
       handleOptionalDependencies(optionalDependencies),
+      patchLoadInstrumentation(updater),
+      // Apply updater updaters, must be the last plugin
+      updater.plugin,
     ],
     external: ["./middleware/handler.mjs"],
     alias: {
@@ -192,7 +199,6 @@ export async function updateWorkerBundledCode(
       (code) => patches.inlineMiddlewareManifestRequire(code, buildOpts),
     ],
     ["exception bubbling", patches.patchExceptionBubbling],
-    ["`loadInstrumentationModule` function", patches.patchLoadInstrumentationModule],
     [
       "`patchAsyncStorage` call",
       (code) =>
@@ -210,21 +216,6 @@ export async function updateWorkerBundledCode(
   await writeFile(workerOutputFile, patchedCode);
 }
 
-function createFixRequiresESBuildPlugin(options: BuildOptions): Plugin {
-  return {
-    name: "replaceRelative",
-    setup(build) {
-      // Note: we (empty) shim require-hook modules as they generate problematic code that uses requires
-      build.onResolve(
-        { filter: getCrossPlatformPathRegex(String.raw`^\./require-hook$`, { escape: false }) },
-        () => ({
-          path: path.join(options.outputDir, "cloudflare-templates/shims/empty.js"),
-        })
-      );
-    },
-  };
-}
-
 /**
  * Gets the path of the worker.js file generated by the build process
  *

packages/cloudflare/src/cli/build/patches/plugins/content-updater.ts

@@ -0,0 +1,65 @@
+/**
+ * ESBuild stops calling `onLoad` hooks after the first hook returns an updated content.
+ *
+ * The updater allows multiple plugins to update the content.
+ */
+
+import { readFile } from "node:fs/promises";
+
+import { type OnLoadArgs, type OnLoadOptions, type Plugin, type PluginBuild } from "esbuild";
+
+export type Callback = (args: {
+  contents: string;
+  path: string;
+}) => string | undefined | Promise<string | undefined>;
+export type Updater = OnLoadOptions & { callback: Callback };
+
+export class ContentUpdater {
+  updaters = new Map<string, Updater>();
+
+  /**
+   * Register a callback to update the file content.
+   *
+   * The callbacks are called in order of registration.
+   *
+   * @param name The name of the plugin (must be unique).
+   * @param options Same options as the `onLoad` hook to restrict updates.
+   * @param callback The callback updating the content.
+   * @returns A noop ESBuild plugin.
+   */
+  updateContent(name: string, options: OnLoadOptions, callback: Callback): Plugin {
+    if (this.updaters.has(name)) {
+      throw new Error(`Plugin "${name}" already registered`);
+    }
+    this.updaters.set(name, { ...options, callback });
+    return {
+      name,
+      setup() {},
+    };
+  }
+
+  /**
+   * Returns an ESBuild plugin applying the registered updates.
+   */
+  get plugin() {
+    return {
+      name: "aggregate-on-load",
+
+      setup: async (build: PluginBuild) => {
+        build.onLoad({ filter: /\.(js|mjs|cjs|jsx|ts|tsx)$/ }, async (args: OnLoadArgs) => {
+          let contents = await readFile(args.path, "utf-8");
+          for (const { filter, namespace, callback } of this.updaters.values()) {
+            if (namespace !== undefined && args.namespace !== namespace) {
+              continue;
+            }
+            if (!filter.test(args.path)) {
+              continue;
+            }
+            contents = (await callback({ contents, path: args.path })) ?? contents;
+          }
+          return { contents };
+        });
+      },
+    };
+  }
+}

packages/cloudflare/src/cli/build/patches/plugins/load-instrumentation.spec.ts

@@ -0,0 +1,48 @@
+import { describe, expect, test } from "vitest";
+
+import { patchCode } from "../ast/util.js";
+import { instrumentationRule } from "./load-instrumentation.js";
+
+describe("LoadInstrumentationModule", () => {
+  test("patch", () => {
+    const code = `
+export default class NextNodeServer extends BaseServer<
+  Options,
+  NodeNextRequest,
+  NodeNextResponse
+> {
+  protected async loadInstrumentationModule() {
+    if (!this.serverOptions.dev) {
+      try {
+        this.instrumentation = await dynamicRequire(
+          resolve(
+            this.serverOptions.dir || '.',
+            this.serverOptions.conf.distDir!,
+            'server',
+            INSTRUMENTATION_HOOK_FILENAME
+          )
+        )
+      } catch (err: any) {
+        if (err.code !== 'MODULE_NOT_FOUND') {
+          throw new Error(
+            'An error occurred while loading the instrumentation hook',
+            { cause: err }
+          )
+        }
+      }
+    }
+    return this.instrumentation
+  }
+}`;
+
+    expect(patchCode(code, instrumentationRule)).toMatchInlineSnapshot(`
+      "export default class NextNodeServer extends BaseServer<
+        Options,
+        NodeNextRequest,
+        NodeNextResponse
+      > {
+        async loadInstrumentationModule() { }
+      }"
+    `);
+  });
+});

packages/cloudflare/src/cli/build/patches/plugins/load-instrumentation.ts

@@ -0,0 +1,28 @@
+/**
+ * `loadInstrumentationModule` uses a dynamic require which is not supported.
+ */
+
+import { patchCode } from "../ast/util.js";
+import type { ContentUpdater } from "./content-updater.js";
+
+export const instrumentationRule = `
+rule:
+  kind: method_definition
+  all:
+    - has: {field: name, regex: ^loadInstrumentationModule$}
+    - has: {pattern: dynamicRequire, stopBy: end}
+
+fix: async loadInstrumentationModule() { }
+`;
+
+export function patchLoadInstrumentation(updater: ContentUpdater) {
+  return updater.updateContent(
+    "patch-load-instrumentation",
+    { filter: /\.(js|mjs|cjs|jsx|ts|tsx)$/ },
+    ({ contents }) => {
+      if (/async loadInstrumentationModule\(/.test(contents)) {
+        return patchCode(contents, instrumentationRule);
+      }
+    }
+  );
+}

packages/cloudflare/src/cli/build/patches/plugins/require-hook.ts

@@ -0,0 +1,20 @@
+import { join } from "node:path";
+
+import type { BuildOptions } from "@opennextjs/aws/build/helper.js";
+import { getCrossPlatformPathRegex } from "@opennextjs/aws/utils/regex.js";
+import type { Plugin } from "esbuild";
+
+export function shimRequireHook(options: BuildOptions): Plugin {
+  return {
+    name: "replaceRelative",
+    setup(build) {
+      // Note: we (empty) shim require-hook modules as they generate problematic code that uses requires
+      build.onResolve(
+        { filter: getCrossPlatformPathRegex(String.raw`^\./require-hook$`, { escape: false }) },
+        () => ({
+          path: join(options.outputDir, "cloudflare-templates/shims/empty.js"),
+        })
+      );
+    },
+  };
+}

packages/cloudflare/src/cli/build/patches/plugins/require-page.ts

@@ -3,28 +3,22 @@ import { join } from "node:path";
 
 import { type BuildOptions, getPackagePath } from "@opennextjs/aws/build/helper.js";
 import { getCrossPlatformPathRegex } from "@opennextjs/aws/utils/regex.js";
-import type { PluginBuild } from "esbuild";
 
 import { patchCode, type RuleConfig } from "../ast/util.js";
+import type { ContentUpdater } from "./content-updater.js";
 
-export function inlineRequirePagePlugin(buildOpts: BuildOptions) {
-  return {
-    name: "inline-require-page",
-
-    setup: async (build: PluginBuild) => {
-      build.onLoad(
-        {
-          filter: getCrossPlatformPathRegex(String.raw`/next/dist/server/require\.js$`, { escape: false }),
-        },
-        async ({ path }) => {
-          const jsCode = await readFile(path, "utf8");
-          if (/function requirePage\(/.test(jsCode)) {
-            return { contents: patchCode(jsCode, await getRule(buildOpts)) };
-          }
-        }
-      );
+export function inlineRequirePagePlugin(updater: ContentUpdater, buildOpts: BuildOptions) {
+  return updater.updateContent(
+    "inline-require-page",
+    {
+      filter: getCrossPlatformPathRegex(String.raw`/next/dist/server/require\.js$`, { escape: false }),
     },
-  };
+    async ({ contents }) => {
+      if (/function requirePage\(/.test(contents)) {
+        return patchCode(contents, await getRule(buildOpts));
+      }
+    }
+  );
 }
 
 async function getRule(buildOpts: BuildOptions) {

packages/cloudflare/src/cli/build/patches/plugins/require.ts

@@ -1,54 +1,44 @@
-import fs from "node:fs/promises";
+import type { ContentUpdater } from "./content-updater";
 
-import type { PluginBuild } from "esbuild";
+export function fixRequire(updater: ContentUpdater) {
+  return updater.updateContent("fix-require", { filter: /\.(js|mjs|cjs|jsx|ts|tsx)$/ }, ({ contents }) => {
+    // `eval(...)` is not supported by workerd.
+    contents = contents.replaceAll(`eval("require")`, "require");
 
-export function fixRequire() {
-  return {
-    name: "fix-require",
+    // `@opentelemetry` has a few issues.
+    //
+    // Next.js has the following code in `next/dist/server/lib/trace/tracer.js`:
+    //
+    //     try {
+    //       api = require('@opentelemetry/api');
+    //     } catch (err) {
+    //       api = require('next/dist/compiled/@opentelemetry/api');
+    //     }
+    //
+    // The intent is to allow users to install their own version of `@opentelemetry/api`.
+    //
+    // The problem is that even when users do not explicitely install `@opentelemetry/api`,
+    // `require('@opentelemetry/api')` resolves to the package which is a dependency
+    // of Next.
+    //
+    // The second problem is that when Next traces files, it would not copy the `api/build/esm`
+    // folder (used by the `module` conditions in package.json) it would only copy `api/build/src`.
+    // This could be solved by updating the next config:
+    //
+    //     const nextConfig: NextConfig = {
+    //       // ...
+    //       outputFileTracingIncludes: {
+    //         "*": ["./node_modules/@opentelemetry/api/build/**/*"],
+    //       },
+    //     };
+    //
+    // We can consider doing that when we want to enable users to install their own version
+    // of `@opentelemetry/api`. For now we simply use the pre-compiled version.
+    contents = contents.replace(
+      /require\(.@opentelemetry\/api.\)/g,
+      `require("next/dist/compiled/@opentelemetry/api")`
+    );
 
-    setup: async (build: PluginBuild) => {
-      build.onLoad({ filter: /\.(js|mjs|cjs|jsx|ts|tsx)$/ }, async ({ path }) => {
-        let contents = await fs.readFile(path, "utf-8");
-
-        // `eval(...)` is not supported by workerd.
-        contents = contents.replaceAll(`eval("require")`, "require");
-
-        // `@opentelemetry` has a few issues.
-        //
-        // Next.js has the following code in `next/dist/server/lib/trace/tracer.js`:
-        //
-        //     try {
-        //       api = require('@opentelemetry/api');
-        //     } catch (err) {
-        //       api = require('next/dist/compiled/@opentelemetry/api');
-        //     }
-        //
-        // The intent is to allow users to install their own version of `@opentelemetry/api`.
-        //
-        // The problem is that even when users do not explicitely install `@opentelemetry/api`,
-        // `require('@opentelemetry/api')` resolves to the package which is a dependency
-        // of Next.
-        //
-        // The second problem is that when Next traces files, it would not copy the `api/build/esm`
-        // folder (used by the `module` conditions in package.json) it would only copy `api/build/src`.
-        // This could be solved by updating the next config:
-        //
-        //     const nextConfig: NextConfig = {
-        //       // ...
-        //       outputFileTracingIncludes: {
-        //         "*": ["./node_modules/@opentelemetry/api/build/**/*"],
-        //       },
-        //     };
-        //
-        // We can consider doing that when we want to enable users to install their own version
-        // of `@opentelemetry/api`. For now we simply use the pre-compiled version.
-        contents = contents.replace(
-          /require\(.@opentelemetry\/api.\)/g,
-          `require("next/dist/compiled/@opentelemetry/api")`
-        );
-
-        return { contents };
-      });
-    },
-  };
+    return contents;
+  });
 }

packages/cloudflare/src/cli/build/patches/to-investigate/index.ts

@@ -2,5 +2,4 @@ export * from "./inline-eval-manifest.js";
 export * from "./inline-middleware-manifest-require.js";
 export * from "./patch-exception-bubbling.js";
 export * from "./patch-find-dir.js";
-export * from "./patch-load-instrumentation-module.js";
 export * from "./patch-read-file.js";