ref(profiling): Conditionally shim cjs globals

dev-packages/e2e-tests/test-applications/node-profiling/build.shimmed.mjs

@@ -0,0 +1,29 @@
+// Because bundlers can now predetermine a static set of binaries we need to ensure those binaries
+// actually exists, else we risk a compile time error when bundling the package. This could happen
+// if we added a new binary in cpu_profiler.ts, but forgot to prebuild binaries for it. Because CI
+// only runs integration and unit tests, this change would be missed and could end up in a release.
+// Therefor, once all binaries are precompiled in CI and tests pass, run esbuild with bundle:true
+// which will copy all binaries to the outfile folder and throw if any of them are missing.
+import esbuild from 'esbuild';
+
+console.log('Running build using esbuild version', esbuild.version);
+
+esbuild.buildSync({
+  platform: 'node',
+  entryPoints: ['./index.ts'],
+  outfile: './dist/index.shimmed.mjs',
+  target: 'esnext',
+  format: 'esm',
+  bundle: true,
+  loader: { '.node': 'copy' },
+  banner: {
+    js: `
+        import { dirname } from 'node:path';
+        import { fileURLToPath } from 'node:url';
+        import { createRequire } from 'node:module';
+        const require = createRequire(import.meta.url);
+        const __filename = fileURLToPath(import.meta.url);
+        const __dirname = dirname(__filename);
+        `,
+  },
+});

dev-packages/e2e-tests/test-applications/node-profiling/package.json

@@ -4,9 +4,9 @@
   "private": true,
   "scripts": {
     "typecheck": "tsc --noEmit",
-    "build": "node build.mjs",
-    "test": "npm run build && node dist/index.js",
-    "clean": "npx rimraf node_modules",
+    "build": "node build.mjs && node build.shimmed.mjs",
+    "test": "node dist/index.js && node dist/index.shimmed.mjs",
+    "clean": "npx rimraf node_modules dist",
     "test:build": "npm run typecheck && npm run build",
     "test:assert": "npm run test"
   },

packages/profiling-node/rollup.npm.config.mjs

@@ -1,12 +1,49 @@
 import commonjs from '@rollup/plugin-commonjs';
-import esmshim from '@rollup/plugin-esm-shim';
 import { makeBaseNPMConfig, makeNPMConfigVariants } from '@sentry-internal/rollup-utils';
 
-export default makeNPMConfigVariants(
+export const ESMShim = `
+import cjsUrl from 'node:url';
+import cjsPath from 'node:path';
+import cjsModule from 'node:module';
+
+if(typeof __filename === 'undefined'){
+  globalThis.__filename = cjsUrl.fileURLToPath(import.meta.url);
+}
+
+if(typeof __dirname === 'undefined'){
+  globalThis.__dirname = cjsPath.dirname(__filename);
+}
+
+if(typeof require === 'undefined'){
+  globalThis.require = cjsModule.createRequire(import.meta.url);
+}
+`;
+
+function makeESMShimPlugin(shim) {
+  return {
+    transform(code) {
+      const SHIM_REGEXP = /\/\/ #START_SENTRY_ESM_SHIM[\s\S]*?\/\/ #END_SENTRY_ESM_SHIM/;
+      return code.replace(SHIM_REGEXP, shim);
+    },
+  };
+}
+
+const variants = makeNPMConfigVariants(
   makeBaseNPMConfig({
     packageSpecificConfig: {
       output: { dir: 'lib', preserveModules: false },
-      plugins: [commonjs(), esmshim()],
+      plugins: [commonjs()],
     },
   }),
 );
+
+for (const variant of variants) {
+  if (variant.output.format === 'esm') {
+    variant.plugins.push(makeESMShimPlugin(ESMShim));
+  } else {
+    // Remove the ESM shim comment
+    variant.plugins.push(makeESMShimPlugin(''));
+  }
+}
+
+export default variants;

packages/profiling-node/src/cpu_profiler.ts

@@ -15,6 +15,12 @@ import type {
 } from './types';
 import type { ProfileFormat } from './types';
 
+// #START_SENTRY_ESM_SHIM
+// When building for ESM, we shim require to use createRequire and __dirname.
+// We need to do this because .node extensions in esm are not supported.
+// The comment below this line exists as a placeholder for where to insert the shim.
+// #END_SENTRY_ESM_SHIM
+
 const stdlib = familySync();
 const platform = process.env['BUILD_PLATFORM'] || _platform();
 const arch = process.env['BUILD_ARCH'] || _arch();