fix(metro): Use env for default Babel transformer path

CHANGELOG.md

@@ -6,6 +6,13 @@
 > make sure you follow our [migration guide](https://docs.sentry.io/platforms/react-native/migration/) first.
 <!-- prettier-ignore-end -->
 
+## Unreleased
+
+### Fixes
+
+- Remove `.sentry` tmp directory and use environmental variables instead to save default Babel transformer path ([#4298](https://github.com/getsentry/sentry-react-native/pull/4298))
+  - This resolves concurrency issues when running multiple bundle processes
+
 ## 6.3.0-beta.1
 
 ### Features

packages/core/src/js/tools/metroconfig.ts

@@ -5,7 +5,7 @@ import * as process from 'process';
 import { env } from 'process';
 
 import { enableLogger } from './enableLogger';
-import { cleanDefaultBabelTransformerPath, saveDefaultBabelTransformerPath } from './sentryBabelTransformerUtils';
+import { setSentryDefaultBabelTransformerPathEnv } from './sentryBabelTransformerUtils';
 import { createSentryMetroSerializer, unstable_beforeAssetSerializationPlugin } from './sentryMetroSerializer';
 import type { DefaultConfigOptions } from './vendor/expo/expoconfig';
 export * from './sentryMetroSerializer';
@@ -143,10 +143,7 @@ export function withSentryBabelTransformer(config: MetroConfig): MetroConfig {
   }
 
   if (defaultBabelTransformerPath) {
-    saveDefaultBabelTransformerPath(defaultBabelTransformerPath);
-    process.on('exit', () => {
-      cleanDefaultBabelTransformerPath();
-    });
+    setSentryDefaultBabelTransformerPathEnv(defaultBabelTransformerPath);
   }
 
   return {

packages/core/src/js/tools/sentryBabelTransformerUtils.ts

@@ -1,62 +1,34 @@
 import { logger } from '@sentry/utils';
-import * as fs from 'fs';
-import * as path from 'path';
 import * as process from 'process';
 
 import type { BabelTransformer } from './vendor/metro/metroBabelTransformer';
 
-/**
- * Saves default Babel transformer path to the project root.
- */
-export function saveDefaultBabelTransformerPath(defaultBabelTransformerPath: string): void {
-  try {
-    fs.mkdirSync(path.join(process.cwd(), '.sentry'), { recursive: true });
-    fs.writeFileSync(getDefaultBabelTransformerPath(), defaultBabelTransformerPath);
-    logger.debug('Saved default Babel transformer path');
-  } catch (e) {
-    // eslint-disable-next-line no-console
-    console.error('[Sentry] Failed to save default Babel transformer path:', e);
-  }
-}
+export const SENTRY_DEFAULT_BABEL_TRANSFORMER_PATH = 'SENTRY_DEFAULT_BABEL_TRANSFORMER_PATH';
 
 /**
- * Reads default Babel transformer path from the project root.
+ * Sets default Babel transformer path to the environment variables.
  */
-export function readDefaultBabelTransformerPath(): string | undefined {
-  try {
-    return fs.readFileSync(getDefaultBabelTransformerPath()).toString();
-  } catch (e) {
-    // eslint-disable-next-line no-console
-    console.error('[Sentry] Failed to read default Babel transformer path:', e);
-  }
-  return undefined;
+export function setSentryDefaultBabelTransformerPathEnv(defaultBabelTransformerPath: string): void {
+  process.env[SENTRY_DEFAULT_BABEL_TRANSFORMER_PATH] = defaultBabelTransformerPath;
+  logger.debug(`Saved default Babel transformer path ${defaultBabelTransformerPath}`);
 }
 
 /**
- * Cleans default Babel transformer path from the project root.
+ * Reads default Babel transformer path from the environment variables.
  */
-export function cleanDefaultBabelTransformerPath(): void {
-  try {
-    fs.unlinkSync(getDefaultBabelTransformerPath());
-    logger.debug('Cleaned default Babel transformer path');
-  } catch (e) {
-    // We don't want to fail the build if we can't clean the file
-    // eslint-disable-next-line no-console
-    console.error('[Sentry] Failed to clean default Babel transformer path:', e);
-  }
-}
-
-function getDefaultBabelTransformerPath(): string {
-  return path.join(process.cwd(), '.sentry/.defaultBabelTransformerPath');
+export function getSentryDefaultBabelTransformerPathEnv(): string | undefined {
+  return process.env[SENTRY_DEFAULT_BABEL_TRANSFORMER_PATH];
 }
 
 /**
  * Loads default Babel transformer from `@react-native/metro-config` -> `@react-native/metro-babel-transformer`.
  */
 export function loadDefaultBabelTransformer(): BabelTransformer {
-  const defaultBabelTransformerPath = readDefaultBabelTransformerPath();
+  const defaultBabelTransformerPath = getSentryDefaultBabelTransformerPathEnv();
   if (!defaultBabelTransformerPath) {
-    throw new Error('Default Babel Transformer Path not found in `.sentry` directory.');
+    throw new Error(
+      `Default Babel transformer path environment variable ${SENTRY_DEFAULT_BABEL_TRANSFORMER_PATH} is not set.`,
+    );
   }
 
   logger.debug(`Loading default Babel transformer from ${defaultBabelTransformerPath}`);

packages/core/test/tools/metroconfig.test.ts

@@ -1,16 +1,5 @@
-jest.mock('fs', () => {
-  return {
-    readFile: jest.fn(),
-    mkdirSync: jest.fn(),
-    writeFileSync: jest.fn(),
-    unlinkSync: jest.fn(),
-  };
-});
-
 import type { getDefaultConfig } from 'expo/metro-config';
-import * as fs from 'fs';
 import type { MetroConfig } from 'metro';
-import * as path from 'path';
 import * as process from 'process';
 
 import {
@@ -19,6 +8,7 @@ import {
   withSentryFramesCollapsed,
   withSentryResolver,
 } from '../../src/js/tools/metroconfig';
+import { SENTRY_DEFAULT_BABEL_TRANSFORMER_PATH } from '../../src/js/tools/sentryBabelTransformerUtils';
 
 type MetroFrame = Parameters<Required<Required<MetroConfig>['symbolicator']>['customizeFrame']>[0];
 
@@ -69,43 +59,16 @@ describe('metroconfig', () => {
       },
     );
 
-    test.each([
-      [{ transformer: { babelTransformerPath: 'babelTransformerPath' }, projectRoot: 'project/root' }],
-      [{ transformer: { babelTransformerPath: 'babelTransformerPath' } }],
-    ])('save default babel transformer path to a file', () => {
+    test('save default babel transformer path to environment variable', () => {
       const defaultBabelTransformerPath = '/default/babel/transformer';
 
       withSentryBabelTransformer({
         transformer: {
           babelTransformerPath: defaultBabelTransformerPath,
         },
-        projectRoot: 'project/root',
       });
 
-      expect(fs.mkdirSync).toHaveBeenCalledWith(path.join(process.cwd(), '.sentry'), { recursive: true });
-      expect(fs.writeFileSync).toHaveBeenCalledWith(
-        path.join(process.cwd(), '.sentry/.defaultBabelTransformerPath'),
-        defaultBabelTransformerPath,
-      );
-    });
-
-    test('clean default babel transformer path file on exit', () => {
-      const processOnSpy: jest.SpyInstance = jest.spyOn(process, 'on');
-
-      const defaultBabelTransformerPath = 'defaultBabelTransformerPath';
-
-      withSentryBabelTransformer({
-        transformer: {
-          babelTransformerPath: defaultBabelTransformerPath,
-        },
-        projectRoot: 'project/root',
-      });
-
-      const actualExitHandler: () => void | undefined = processOnSpy.mock.calls[0][1];
-      actualExitHandler?.();
-
-      expect(processOnSpy).toHaveBeenCalledWith('exit', expect.any(Function));
-      expect(fs.unlinkSync).toHaveBeenCalledWith(path.join(process.cwd(), '.sentry/.defaultBabelTransformerPath'));
+      expect(process.env[SENTRY_DEFAULT_BABEL_TRANSFORMER_PATH]).toBe(defaultBabelTransformerPath);
     });
 
     test('return config with sentry babel transformer path', () => {

packages/core/test/tools/sentryBabelTransformer.test.ts

@@ -1,14 +1,8 @@
-jest.mock('fs', () => {
-  return {
-    readFileSync: jest.fn(),
-  };
-});
+import * as process from 'process';
 
-import * as fs from 'fs';
+import { SENTRY_DEFAULT_BABEL_TRANSFORMER_PATH } from '../../src/js/tools/sentryBabelTransformerUtils';
 
-// needs to be defined before sentryBabelTransformer is imported
-// the transformer is created on import (side effect)
-(fs.readFileSync as jest.Mock).mockReturnValue(require.resolve('./fixtures/mockBabelTransformer.js'));
+process.env[SENTRY_DEFAULT_BABEL_TRANSFORMER_PATH] = require.resolve('./fixtures/mockBabelTransformer.js');
 
 import * as SentryBabelTransformer from '../../src/js/tools/sentryBabelTransformer';
 import type { BabelTransformerArgs } from '../../src/js/tools/vendor/metro/metroBabelTransformer';