android: fold waitForFile into connect retry loop

[gmaclennan]

Summary

In release Android builds, comapeo.listProjects() (and any other RPC) hangs forever on the JS side because the main process's comapeo.sock IPC client never connects.

Root cause — ComapeoCoreModule.OnCreate constructs two NodeJSIPC instances back-to-back. Each calls waitForFile() which arms an Android FileObserver on the same parent directory /data/user/0/<pkg>/files/. AOSP's FileObserver$ObserverThread keeps a wd → WeakReference<FileObserver> SparseArray; inotify_add_watch returns the same wd for repeated watches on the same path, so the second registration overwrites the first in the map. The first observer (comapeo.sock) silently never fires. Public confirmation: issuetracker.google.com/37017033.

Debug builds happened to mask this because Metro bundle loading delays Module.OnCreate until after the backend has bound both sockets — file.exists() returns true and the observer is bypassed. Release builds start JS fast enough that both observers register before the backend gets to bind().

Fix — drop waitForFile entirely. LocalSocket.connect throws IOException for both ENOENT (file missing) and ECONNREFUSED (file exists, server not yet accepting) — the same primitive already handles both phases of backend startup. Replace connectWithRetry's 5-attempt exponential backoff with a fixed 50 ms cadence bounded by a 30 s deadline (matching the prior cumulative budget). One race-prone primitive instead of two; no FileObserver dependency.

Net diff: −436 lines.

Test plan

• ./gradlew :comapeo-core-react-native:testReleaseUnitTest passes
• ./gradlew assembleRelease succeeds for apps/testing
• Release APK on emulator reaches STARTED in ~2 s (was hanging at 30 s timeout)
• All 36 jasmine RPC tests in apps/testing pass on the release build

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Fixes an Android release-build hang where the JS-side IPC client could wait forever due to overlapping FileObserver registrations on the same directory. The approach removes the waitForFile primitive and relies solely on LocalSocket.connect() retrying until the backend is ready.

Changes:

• Remove waitForFile (FileObserver-based) and its associated tests/docs.
• Replace the prior exponential-backoff connect strategy with a fixed 50ms retry cadence bounded by a 30s deadline in NodeJSIPC.
• Update architecture/testing docs to reflect the new connection behavior.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
e2e/README.md	Removes references/section for the deleted WatchForFileTest.
docs/ARCHITECTURE.md	Updates IPC startup narrative and timeout table to match the new connect retry loop.
apps/example/tests/android/WaitForFileTest.kt	Deletes example-app instrumented tests for waitForFile.
android/src/test/java/com/comapeo/core/WatchForFileTimeoutTest.kt	Deletes JVM tests that existed only to validate the old waitForFile timeout pattern.
android/src/main/java/com/comapeo/core/watchForFile.kt	Deletes the FileObserver-based waitForFile helper.
android/src/main/java/com/comapeo/core/NodeJSIPC.kt	Removes waitForFile usage and implements a deadline-bounded fixed-interval connect retry loop.
android/src/main/java/com/comapeo/core/ComapeoCoreModule.kt	Updates comment describing IPC startup behavior.
android/src/androidTest/java/com/comapeo/core/WatchForFileTest.kt	Deletes instrumented tests for the removed waitForFile.
agents.md	Removes watchForFile.kt from the Android source tree listing.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.