file-manager/docs/EDGE_CASE_TESTING.md

On-device testing

What has actually been run on hardware, what it found, and what is still unverified. Keep this file honest: an untested claim is a bug waiting to be reported.

Devices used

Device	Android	Notes
Xiaomi M2101K7AG (Redmi, sunny), MIUI V140	12 (API 31), arm64-v8a	A real phone with a real 55 GB library. Auto-rotate was on, so runs happened in both orientations.
AOSP phone AVD	12 (API 31), x86_64	Software emulation — the host exposes no /dev/kvm. Used from M0–M6.

Connecting a phone to this dev container needs one fix: the USB node is created root:plugdev 0660, and the container's user is not in plugdev, so adb cannot open it. An udev rule widening the mode for Android vendors fixes it (/etc/udev/rules.d/51-android.rules), after which adb devices sees the phone.

Verified on the real device

What	Result
First run, no permission granted	The "Choose a folder" prompt appears with both routes offered: Grant full access and Choose folder. Correct — the app has no source yet, so the SAF fallback is the honest state.
Granting "All files access" while the app is alive	The app picks it up on resume and switches from the prompt to the roots view, showing "Internal storage · 50.0 GB free" (matching df). The lifecycle refresh works.
Browsing real storage	Real folders listed alphabetically with correct icons and breadcrumbs ("Internal storage / Download"). Titles render "Internal storage", not the raw volume name.
Text editor, read	Tapping a.txt opened the editor showing its real content.
Text editor, write	Editing and tapping Save persisted to the device — verified independently with adb shell cat.
Storage usage	DCIM 2.7 GB / 668 files, Android 1.2 GB / 5925 files, Music 1.2 GB / 43 files, Pictures 866.4 MB / 5849 files, … sorted largest first with per-row share bars and correct plurals.
Revoking "All files access" mid-use	Returned to the folder prompt without crashing; the app kept running. Graceful degradation confirmed.
Landscape	The whole UI adapts (the phone auto-rotated mid-session): app bar, list, breadcrumbs and dialogs all laid out correctly.
BACK from the roots view	Exits the app, which is the expected Android behaviour.

Bugs this session found — both fixed

1. The first-run copy was wrong. The prompt read "Full access was declined, so pick a folder…" on a device where the user had never declined anything. Reworded to "Without full access you can still work inside one folder you choose here.", which is true whether the user declined or simply has not granted yet. Re-verified on device.

2. The storage-usage screen took ~45–60 seconds to show anything. Measuring the root of a real 55 GB volume blocked on the whole walk with only a spinner for company, which reads as a hang. Two changes:

   • UsageAnalysis now passes the FileEntry down the recursion instead of re-stating every node (the parent's listing already says whether each child is a folder), so the walk costs one listing per directory and nothing more.
   • Rows are published as they are measured through an onProgress callback, and the ViewModel appends them, re-sorting as it goes, so the biggest folders appear while the rest of the tree is still being walked.

   The UI never froze — the progress bar kept animating throughout, which confirms the I/O stays off the main thread — but "slow and silent" is still a defect.

Not verified, and why

• Long-press multi-select via adb. input swipe x y x y 900 is delivered as a plain tap on this MIUI build, so the selection action bar (and therefore compress/extract from the UI) could not be driven from the host. The archive engine itself is covered by end-to-end JVM tests, including a zip-slip archive. Worth a manual pass.
• The SAF folder-picker round trip. Driving the system picker and granting a tree was not attempted; the code path is unit-tested against a stand-in DocumentsProvider.
• Image viewer and thumbnails. Verified on the AVD in M4/M5; not repeated on the phone.
• The foreground-service notification during a long copy. Started in M3 and unit-tested; not observed on hardware.
• Archive creation/extraction against real files. Only exercised in-memory.