How to test a release build with Detox

Testing a release build with Detox runs the app flavor that will ship to users instead of the debug binary used during everyday end-to-end work. This catches release-only failures such as missing bundled assets, minification side effects, signing differences, and configuration values that only exist in the release target.

Detox selects the app and device through a named configuration in the project config file. The release configuration should resolve to a release binary path and a build command that produces that binary before detox test installs it on the simulator or emulator.

Use a real project, simulator or emulator, and test runner for this check; a generic shell can verify Detox CLI options but cannot prove a mobile release binary. Keep --reuse out of the validation run so Detox installs the binary produced by the release build command.

1. Review the release configuration name and app mapping before running the build.

   module.exports = {
     apps: {
       'ios.release': {
         type: 'ios.app',
         binaryPath: 'ios/build/Build/Products/Release-iphonesimulator/MyApp.app',
         build: 'xcodebuild -workspace ios/MyApp.xcworkspace -scheme MyApp -configuration Release -sdk iphonesimulator -derivedDataPath ios/build'
       }
     },
     devices: {
       simulator: {
         type: 'ios.simulator',
         device: { type: 'iPhone 15' }
       }
     },
     configurations: {
       'ios.sim.release': {
         device: 'simulator',
         app: 'ios.release'
       }
     }
   };

   Use the matching Android release configuration name when the release binary is an APK; the Detox command stays the same once the configuration is selected.

2. Build the release binary for the selected configuration.

   $ npx detox build --configuration ios.sim.release
   detox[build] xcodebuild -workspace ios/MyApp.xcworkspace -scheme MyApp -configuration Release -sdk iphonesimulator -derivedDataPath ios/build
   ** BUILD SUCCEEDED **

   Add --if-missing only for repeat checks where an existing release binary is acceptable. Leave it off when the task is to prove a fresh release build.

3. Run the Detox suite against the release configuration.

   $ npx detox test --configuration ios.sim.release --cleanup
   detox[run_tests] ios.sim.release
   PASS e2e/release-smoke.test.js
     release smoke
       ✓ opens the release build and reaches Home (6.4 s)
   
   Test Suites: 1 passed, 1 total
   Tests:       1 passed, 1 total

   --cleanup shuts down the simulator after the run. Add --headless for CI jobs that should launch the device without a visible simulator window.

4. Check the test-run summary before accepting the release build.

   PASS e2e/release-smoke.test.js
   Test Suites: 1 passed, 1 total
   Tests:       1 passed, 1 total

   A passing debug configuration does not prove the release binary. The configuration name in the summary must be the release target used for the build.