add getBuiltInstrumentationPath utility

dario-piotrowicz · dario-piotrowicz · commit e27cd2e25d09 · 2025-02-25T11:02:35.000Z
diff --git a/packages/cloudflare/src/cli/build/patches/plugins/load-instrumentation.ts b/packages/cloudflare/src/cli/build/patches/plugins/load-instrumentation.ts
@@ -2,23 +2,14 @@
  * `loadInstrumentationModule` uses a dynamic require which is not supported.
  */
 
-import { existsSync } from "node:fs";
-import { join } from "node:path";
-
-import { type BuildOptions, getPackagePath } from "@opennextjs/aws/build/helper.js";
+import { type BuildOptions } from "@opennextjs/aws/build/helper.js";
 
+import { getBuiltInstrumentationPath } from "../../utils/get-built-instrumentation-path.js";
 import { patchCode } from "../ast/util.js";
 import type { ContentUpdater } from "./content-updater.js";
 
 export function patchLoadInstrumentation(updater: ContentUpdater, buildOpts: BuildOptions) {
-  const { outputDir } = buildOpts;
-
-  const baseDir = join(outputDir, "server-functions/default", getPackagePath(buildOpts));
-  const dotNextDir = join(baseDir, ".next");
-  const maybeBuiltInstrumentationPath = join(dotNextDir, "server", `${INSTRUMENTATION_HOOK_FILENAME}.js`);
-  const builtInstrumentationPath = existsSync(maybeBuiltInstrumentationPath)
-    ? maybeBuiltInstrumentationPath
-    : null;
+  const builtInstrumentationPath = getBuiltInstrumentationPath(buildOpts);
 
   return updater.updateContent(
     "patch-load-instrumentation",
@@ -42,9 +33,3 @@ export async function getRule(builtInstrumentationPath: string | null) {
       }
   `;
 }
-
-/**
- * Pattern to detect instrumentation hooks file
- * (taken from Next.js source: https://github.com/vercel/next.js/blob/1d5820563/packages/next/src/lib/constants.ts#L46-L47)
- */
-const INSTRUMENTATION_HOOK_FILENAME = "instrumentation";
diff --git a/packages/cloudflare/src/cli/build/patches/plugins/prepare-impl.ts b/packages/cloudflare/src/cli/build/patches/plugins/prepare-impl.ts
@@ -4,23 +4,14 @@
  * `prepareImpl` is the method that sets up instrumentation in Next 14 (this is `loadInstrumentationModule` in Next 15).
  */
 
-import { existsSync } from "node:fs";
-import { join } from "node:path";
-
-import { type BuildOptions, getPackagePath } from "@opennextjs/aws/build/helper.js";
+import { type BuildOptions } from "@opennextjs/aws/build/helper.js";
 
+import { getBuiltInstrumentationPath } from "../../utils/get-built-instrumentation-path.js";
 import { patchCode } from "../ast/util.js";
 import type { ContentUpdater } from "./content-updater.js";
 
 export function patchPrepareImpl(updater: ContentUpdater, buildOpts: BuildOptions) {
-  const { outputDir } = buildOpts;
-
-  const baseDir = join(outputDir, "server-functions/default", getPackagePath(buildOpts));
-  const dotNextDir = join(baseDir, ".next");
-  const maybeBuiltInstrumentationPath = join(dotNextDir, "server", `${INSTRUMENTATION_HOOK_FILENAME}.js`);
-  const builtInstrumentationPath = existsSync(maybeBuiltInstrumentationPath)
-    ? maybeBuiltInstrumentationPath
-    : null;
+  const builtInstrumentationPath = getBuiltInstrumentationPath(buildOpts);
 
   return updater.updateContent(
     "patch-prepareImpl",
@@ -46,9 +37,3 @@ export async function getRule(builtInstrumentationPath: string | null) {
         }
   `;
 }
-
-/**
- * Pattern to detect instrumentation hooks file
- * (taken from Next.js source: https://github.com/vercel/next.js/blob/1d5820563/packages/next/src/lib/constants.ts#L46-L47)
- */
-const INSTRUMENTATION_HOOK_FILENAME = "instrumentation";
diff --git a/packages/cloudflare/src/cli/build/utils/get-built-instrumentation-path.ts b/packages/cloudflare/src/cli/build/utils/get-built-instrumentation-path.ts
@@ -0,0 +1,30 @@
+import { existsSync } from "node:fs";
+import { join } from "node:path";
+
+import { type BuildOptions, getPackagePath } from "@opennextjs/aws/build/helper.js";
+
+/**
+ * Gets the instrumentation.js file that the Next.js build process generates when an
+ * instrumentation hook is provided in the app's source
+ *
+ * @param buildOpts the open-next build options
+ * @returns a string pointing to the instrumentation.js file location, or null if such file is not found
+ */
+export function getBuiltInstrumentationPath(buildOpts: BuildOptions): string | null {
+  const { outputDir } = buildOpts;
+
+  const baseDir = join(outputDir, "server-functions/default", getPackagePath(buildOpts));
+  const dotNextDir = join(baseDir, ".next");
+  const maybeBuiltInstrumentationPath = join(dotNextDir, "server", `${INSTRUMENTATION_HOOK_FILENAME}.js`);
+  const builtInstrumentationPath = existsSync(maybeBuiltInstrumentationPath)
+    ? maybeBuiltInstrumentationPath
+    : null;
+
+  return builtInstrumentationPath;
+}
+
+/**
+ * Pattern to detect instrumentation hooks file
+ * (taken from Next.js source: https://github.com/vercel/next.js/blob/1d5820563/packages/next/src/lib/constants.ts#L46-L47)
+ */
+const INSTRUMENTATION_HOOK_FILENAME = "instrumentation";
