fix(macos): keep foreground tracking when browser context fails

[TimeToBuildBob]

Summary

Rebase of #141 (hawai-i) onto current master after #145. Original work is preserved and attributed (Co-Authored-By: hawai-i).

Browser URL/title enrichment is optional, but the macOS Swift watcher used to return without a heartbeat when Chrome/Safari ScriptingBridge failed. Heartbeat merging then extended the previous application across the real browser interval.

This keeps #141's PID-based foreground reconciliation:

• emit a foreground heartbeat even when browser context acquisition fails
• bind tracked app, AX observer, focused window, and emitted app identity to one PID
• repair a missing/stale observer and reject stale AX callbacks
• consume the activated NSRunningApplication from the workspace notification

Conflict with #145

#145 landed on master after #141 opened. The rebase keeps that work:

• axString / axElement CF type checks (the macOS: native helper crashes when NSHTTPURLResponse is bridged as a window-title string #144 NSHTTPURLResponse crash)
• observer teardown that unregisters both title and focused-window notifications and tracks observedApp (the [macOS] aw-watcher-window-macos leaks AXObserver/Mach ports, causing high wired memory #139 Mach-port leak)

Unsafe as? String / as! AXUIElement casts from #141 are not carried forward.

Greptile on #141

P1 (incognito): ScriptingBridge is the only Chrome incognito detector. The original fallback sent AX-derived app + title when that lookup failed. The rebase still emits the Chrome app identity (so tracking stays coherent) but drops title and URL. Successful incognito detection still blanks both app and title.

P2 (tests): make test-swift now compiles with -target …-macosx$(MACOSX_DEPLOYMENT_TARGET) (12.0), matching the production helper.

Validation

Python tests: 77 passed. mypy clean. Swift helper/tests need Darwin CI (macos-latest).

Related

• macOS: keep foreground tracking coherent when browser context fails #141 — original PR (leave open until this lands)
• fix(macos): survive non-string AX titles and stop leaking AXObserver #145 / macOS: native helper crashes when NSHTTPURLResponse is bridged as a window-title string #144 / [macOS] aw-watcher-window-macos leaks AXObserver/Mach ports, causing high wired memory #139 — AX title crash and observer leak, now on master

[TimeToBuildBob]

macos-latest failed at make build-swift: compiling macos.swift together with macos_state.swift rejects top-level expressions (formatter.formatOptions = …, start(), RunLoop.main.run()).

The rebase onto master after #145 dropped the #141 @main wrapper and closure inits. Restored in 8ac81d3. CI is re-running.

[TimeToBuildBob]

CI-green and mergeable — waiting only on a maintainer click.

This PR is ready to merge, but the bot has pull-only access to this repo and can't self-merge — surfacing it here so it isn't lost. The monitoring loop will stop re-flagging it now that this note is posted.

[TimeToBuildBob]

🤖 AI code review

Safe to merge — 2 findings disposed (rejected; fixed in 90aad7f)

_{Updated after inline dispositions on finding threads — this is the current state; the verdict below is frozen at review time and is kept as the historical record of that pass.}

Finding disposition

Finding	Severity	State
aw_watcher_window/macos.swift:211	P0	rejected — The verification step claimed "lines 192-209 contain top-level let main/formatter/encoder" and inferred "'main' attribut
aw_watcher_window/macos.swift:682	P1	fixed in 90aad7fbb413
aw_watcher_window/macos.swift:756	P2	superseded by latest review (not reproduced)
aw_watcher_window/macos.swift:819	P2	superseded by latest review (not reproduced)
aw_watcher_window/macos.swift:746	P2	accepted-tradeoff

Needs a look — P2 only

Confidence 4/5

_{ℹ️ Consensus was degraded on this run: 2 of 3 passes answered, so findings were filtered at 2-of-2 agreement rather than 2-of-3 — less filtered than usual; 2 of 3 fan-out jobs answered, so the findings above were filtered against less evidence than the threshold assumes.}

1 finding · ⚠️ 1 P2

⚠️ P2 medium — aw_watcher_window/macos.swift:746

In updateFocusedWindow, when a new focused window is registered, the code attempts AXObserverAddNotification for the window's title. If that call fails transiently (e.g., the window is not yet ready), it logs the error but continues: oldWindow is set to the new window and a heartbeat is emitted. On subsequent polls, refreshFocusedWindow calls updateFocusedWindow again; because oldWindow now equals the current window, windowChanged becomes false and the add is not re-attempted. Thus the title-change observer is never installed for that window, so live title/URL updates stop being received until the focused window changes or the AX observer is rebuilt. The watcher still sends heartbeats on each poll (every 10s) with the current title read via AX, so data is not lost but is delayed by up to 10 seconds, and tab switches that occur between polls are missed until the next poll.

// Release the observer we created but could not install.
      // AXObserverCreate returns a +1 retained object; use CFRelease to avoid leaking.
      CFRelease(newObserver)
      return

_{How this was verified: Checked the AXObserverCreate signature in the macOS SDK: it is a C function returning AXError, with the observer as an out-parameter, not marked CF_RETURNS_RETAINED. The code's own comment acknowledges the ARC ambiguity. The leak path is reached whenever addResult is neither success nor notificationAlreadyRegistered.}

_{Consensus: 2/2 passes agreed}
Distinct keys: 1 (general)

Previous review passes

commit	score	findings	engine	when
8ac81d39c2f8	4/5	2	llm	2026-09-16 08:53 UTC
9424b4f6a054	1/5	3	llm	2026-09-16 12:44 UTC

_{Reviewed 90aad7fbb413 · openrouter/deepseek/deepseek-v4-flash-0731 · llm (in-band) engine · 594s · about this reviewer}

_{Maintainer commands}

_{@TimeToBuildBob review (own line) — fresh review · @TimeToBuildBob fix — a worker acts on the findings. Once per comment; 👀 = received.}

[TimeToBuildBob]

@greptileai review

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge; no outstanding correctness, security, or repository-rule issue was identified.

Findings

1.  Title registration is not retried ▶

Summary

This PR makes the macOS native watcher keep foreground application tracking coherent when optional browser context acquisition fails.

• Reconciles the foreground application, accessibility observer, focused window, and emitted identity by PID.
• Repairs missing observers and rejects stale accessibility callbacks.
• Emits privacy-safe browser fallback heartbeats without a title or URL when browser scripting fails.
• Adds focused state tests and runs them on Darwin using the supported macOS 12 deployment target.
• The previous title-notification retry finding is fully fixed: failed registration leaves the state retryable on the next poll.

Diagram

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[Startup, activation, or poll] --> B[Select live foreground application]
    B --> C{PID changed or observer missing?}
    C -->|Yes| D[Rebuild AX observer]
    C -->|No| E[Reuse observer]
    D --> F[Read focused window]
    E --> F
    F --> G[Register or retry title notification]
    G --> H{Supported browser?}
    H -->|Chrome or Safari| I[Attempt browser context lookup]
    H -->|Firefox| J[Read URL from AX tree]
    H -->|Other app| K[Keep app and AX title]
    I -->|Success| L[Use browser title and URL]
    I -->|Failure| M[Keep app; blank title and URL]
    J --> N[Apply privacy filters]
    K --> N
    L --> N
    M --> N
    N --> O[Emit foreground heartbeat]

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_{Reviews (2) · Last reviewed commit: "fix(macos): retry title-change observer ..."}

[TimeToBuildBob]

@greptileai review