[BUG] Android: compileDebugKotlin fails on Expo SDK 56 — Promise.reject(code) is now nullable (String?)

[pablogdcr]

Summary

On Expo SDK 56 (expo-modules-core@56.x), @siteed/audio-studio fails to compile on Android because its anonymous Promise implementations override reject(code: String, …) with a non-null code, while the current expo.modules.kotlin.Promise interface declares code as nullable (String?). Kotlin therefore treats the override as not implementing the interface method.

Environment

• @siteed/audio-studio: 3.2.0 (also reproduces on 3.0.3)
• Expo SDK 56, React Native 0.85, expo-modules-core 56.0.14
• Build: app:assembleDebug (Android, arm64-v8a), Kotlin via AGP 8.12

Error

> Task :siteed-audio-studio:compileDebugKotlin FAILED
e: …/net/siteed/audiostudio/AudioRecorderManager.kt:224:40
   Class '<anonymous>' is not abstract and does not implement abstract member:
   fun reject(code: String?, message: String?, cause: Throwable?): Unit
e: 'reject' overrides nothing. Potential signatures for overriding:
   fun reject(code: String?, message: String?, cause: Throwable?): Unit
   fun reject(exception: CodedException): Unit

Root cause

expo-modules-core's Promise interface now declares:

fun reject(code: String?, message: String?, cause: Throwable?)

but the library implements object : Promise { override fun reject(code: String, message: String?, cause: Throwable?) … } (non-null code). The parameter nullability mismatch means the override matches nothing and the abstract member is left unimplemented.

Affected files (18 overrides)

• packages/audio-studio/android/src/main/java/net/siteed/audiostudio/AudioRecorderManager.kt
• packages/audio-studio/android/src/main/java/net/siteed/audiostudio/AudioStudioModule.kt
• packages/audio-studio/android/src/main/java/net/siteed/audiostudio/AudioRecordingService.kt
• packages/audio-studio/android/src/main/java/net/siteed/audiostudio/RecordingActionReceiver.kt

Fix

Change every override fun reject(code: String, message: String?, cause: Throwable?) to code: String? so it matches the interface. This is source-compatible with older expo-modules-core versions too (the bodies don't depend on code being non-null).

I'll open a PR with this change.

[pablogdcr]

Update after investigating: the source fix is already merged on main via #401 ("Start Expo 56 upgrade", branch expo-56-upgrade-promise) — main already declares override fun reject(code: String?, message: String?, cause: Throwable?) in all four files. It's also present in the prerelease 3.2.1-beta.3.

The problem is only that it hasn't reached a stable release: the latest stable, 3.2.0, still ships the non-null code: String overrides and fails to compile on Expo SDK 56. So no code PR is needed here — this is really a request to cut a stable release (e.g. 3.2.1) that includes #401, so consumers on the latest dist-tag aren't blocked on SDK 56.

In the meantime we're pinning 3.2.0 with a patch-package patch that applies the same code: String? change. Thanks for the library! 🙏