fix(web): roll back file editor when save fails

[Adolanium]

What Changed

The file editor now restores the last confirmed text when a save fails.

Edits still apply to the overlay first. If the latest write fails, the overlay goes back, the unsaved mark clears, and a toast says the save failed. A newer edit that landed during that write is not rolled back. The coordinator retries it.

Why

A failed write left the new text on screen. Reload then showed the old disk contents. Easy to think the file was saved.

UI Changes

Failed saves now toast and restore the last confirmed file text. No other visual change.

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for any UI changes (N/A. toast plus restored text is the change)
• I included a video for animation/interaction changes (N/A)

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Note

Medium Risk
Changes autosave and optimistic file cache behavior on write failure; incorrect rollback could drop user edits or show stale disk content, though guards exist for newer overlay edits and interrupted commands.

Overview
Failed file writes no longer leave optimistic editor text on screen. FileSaveCoordinator now tracks lastConfirmedContents (from initialContents and successful saves), exposes syncConfirmed so idle server refreshes update the rollback baseline, and on a non-interrupted persist failure resets internal state and invokes onRollback instead of leaving the file “saved.” Interrupted writes and in-flight newer edits are unchanged: stale failures do not roll back newer typing, and overlapping saves still debounce to the latest revision.

FilePreviewPanel wires this up by passing loaded contents, syncing confirmed text when contents changes without rebuilding the coordinator on every keystroke, and implementing onRollback to restore project file query data, clear pending when appropriate, skip rollback if the overlay already diverged, and show a “Could not save file” error toast.

Tests cover rollback, baseline refresh, interrupted/dispose edge cases, and concurrent edit behavior.

^{Reviewed by Cursor Bugbot for commit de49ca5. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Roll back file editor to last confirmed contents on save failure

• FileSaveCoordinator now tracks a lastConfirmedContents baseline, seeded from a new initialContents option and updated on successful saves and idle external refreshes via syncConfirmed.
• On save failure, the coordinator restores latestContents to the baseline, resets latestRevision to 0, and invokes a new onRollback callback with failedContents, confirmedContents, and the persist result; pending state is intentionally left uncleared so the UI can mark the file as pending.
• Write interruptions detected by isAtomCommandInterrupted are treated as a distinct case — no rollback, no pending change.
• useFileSaveCoordinator wires initialContents and a new useEffect that calls coordinator.syncConfirmed(contents) on external content changes, and implements onRollback to reset query data and show an error toast.
• Behavioral Change: pending state is no longer cleared on save failure or interruption; callers that relied on pending being cleared after a failed save will need updating.

^{Macroscope summarized de49ca5.}

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[macroscopeapp]

UI consistency review found three issues in the new file-save rollback path. The main one is that an interrupted write is now treated as a failed write, which makes the editor discard the user's text and surface a save error — every other command result handler in apps/web filters interrupted results out first.

^{Posted via Macroscope — UI Consistency}

[macroscopeapp]

Approvability

Verdict: Approved at de49ca5

Macroscope's review found this PR approvable — This is a focused fix to restore the last confirmed file contents after autosave failures, with guarded handling for concurrent edits and interrupted writes. Production changes are confined to the file editor flow and are accompanied by targeted coordinator tests.

^{You can add or adjust custom eligibility rules. Learn more.}

[macroscopeapp]

One finding: the rollback toast calls squashAtomCommandFailure on an un-narrowed AtomCommandResult, which does not typecheck. Details inline.

^{Posted via Macroscope — UI Consistency}

[macroscopeapp]

One finding on the new after-dispose rollback path: the coordinator's unconditional onPendingChange(false) cancels the "mark pending again" branch that onRollback uses when a newer overlay is present, so the file tab loses its unsaved indicator while unsaved text is still on screen.

^{Posted via Macroscope — UI Consistency}

[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.

There are 2 total unresolved issues (including 1 from previous review).

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^{Reviewed by Cursor Bugbot for commit dc19c82. Configure here.}