safe-wallet/docs/solutions/workflow-issues/direct-native-file-edits-in-expo-project-20260319.md

module, date, problem_type, component, symptoms, root_cause, resolution_type, severity, tags

module	date	problem_type	component	symptoms	root_cause	resolution_type	severity	tags
Mobile	2026-03-19	workflow_issue	development_workflow	Podfile modified directly but changes lost on next prebuild/native regeneration Expo plugin config.ts updated but dist/ not rebuilt, so changes not applied MMKV pod pinned to master in Podfile instead of through Expo config plugin	missing_workflow_step	workflow_improvement	high	expo podfile native-generation expo-plugins build-step ios mobile

Direct Native File Edits in Expo Project

Problem

During an upgrade of react-native-quick-crypto and react-native-mmkv, the iOS Podfile was modified directly to:

1. Remove a pod 'MMKV' line
2. Add a post_install block with MMKV_IOS_EXTENSION preprocessor macro
3. Change the MMKV pod version pin

These changes were made to the generated apps/mobile/ios/Podfile rather than through the Expo config plugin that generates it (expo-plugins/notification-service-ios).

Additionally, when the Expo plugin source (plugin/config.ts) was correctly updated, the build step (yarn build in the plugin directory) was not run, so the compiled output in dist/ was stale and the changes were not applied during the next prebuild.

Root Cause

Two workflow gaps:

1. Expo continuously regenerates native files. The ios/ and android/ directories are generated artifacts in an Expo managed/custom dev client workflow. Direct edits to Podfile, AppDelegate, Info.plist, etc. will be overwritten on the next expo prebuild. All native configuration must flow through Expo config plugins or app.config.ts.

2. Expo plugins with a build step require compilation. The notification-service-ios plugin has a TypeScript source in plugin/ and compiled output in dist/. The app.plugin.js entry point loads from dist/. Editing plugin/config.ts without running yarn build (or the plugin's build script) means the changes never reach the compiled output that Expo actually reads.

Solution

Rule 1: Never directly edit generated native files

• apps/mobile/ios/Podfile - generated, edit via Expo plugins
• apps/mobile/ios/*.pbxproj - generated, edit via Expo plugins
• apps/mobile/android/build.gradle - generated, edit via Expo plugins

Instead, modify the Expo config plugin that generates the content:

# The Podfile content for the notification extension is templated here:
expo-plugins/notification-service-ios/plugin/config.ts  # PODFILE_MODIF_NEEDED constant

# NOT here:
apps/mobile/ios/Podfile  # This is a generated output

Rule 2: Always run the plugin build step after editing plugin source

# After editing any file in expo-plugins/notification-service-ios/plugin/
cd expo-plugins/notification-service-ios
yarn build  # Compiles TS and copies ios-notification-service-files/ to dist/

# Then regenerate native project
cd apps/mobile
npx expo prebuild --clean  # Regenerates ios/ and android/ from plugins

The build script from package.json:

"build": "rm -rf dist && tsc && cp -a ./ios-notification-service-files dist/ios-notification-service-files/"

This copies both the compiled TypeScript AND the Swift/plist template files into dist/.

Prevention

Before modifying any native iOS/Android file in an Expo project:

1. Ask: "Is this file generated?" If it's under ios/ or android/, it almost certainly is.
2. Find the config plugin that generates or modifies it. Search expo-plugins/ and app.config.ts.
3. Edit the plugin source, not the generated output.
4. Run the plugin build step if the plugin has one (yarn build).
5. Run expo prebuild to verify changes are applied correctly.

Related

• expo-plugins/notification-service-ios/ - The Expo plugin for iOS notification service extension
• apps/mobile/ios/Podfile - Generated Podfile (do not edit directly)