Add automatic checkbox reset based on file modification time

[Copilot]

Plan: Reset checkbox when file modification time changes

Requirement

• Reset checkboxes when file modification time changes since checkbox was ticked (not just git status change)
• Checkbox signifies human has reviewed the file
• Feature should be OFF by default
• Add config option to enable this behavior

Implementation Plan

• Add new configuration option gitTreeCompare.resetCheckboxOnFileChange
• Change checkbox state storage to include timestamp when checkbox was checked
• Modify handleChangeCheckboxState to store timestamp along with state
• Modify updateDiff to check file modification time instead of/in addition to git status
• Get file modification time (mtime) for each file
• Compare mtime with checkbox timestamp
• Reset checkbox if file was modified after checkbox was checked
• Build and verify no compilation errors
• Optimize file stat calls to use async promises in parallel
• Add error logging for debugging
• Improve filtering efficiency
• Use proper TypeScript error types
• Fix variable shadowing issues
• Run final code review
• Run CodeQL security scan
• Remove old status-based behavior
• Resolve merge conflicts with master branch
• Address PR review feedback

PR Review Changes Addressed

1. Timestamp handling: Only set timestamp when checking items, preserve when unchecking
2. Comment clarity: Updated to reflect that timestamp is for checked state
3. Race condition fix: Use >= instead of > for file mtime comparison
4. Folder state cleanup: Fixed to not delete folder checkbox states incorrectly
5. Tree refresh consolidation: Single refresh point to avoid redundant updates
6. Performance optimization: Added caching for folder checkbox state computation

Summary

Successfully implemented checkbox reset based on file modification time and addressed all PR review feedback.

Final State:

• Feature is opt-in via resetCheckboxOnFileChange config (default: false)
• When enabled: Resets checkboxes when file mtime >= checkbox timestamp
• When disabled: Checkboxes persist indefinitely
• All code compiles successfully
• Compatible with latest master branch changes
• Performance optimized with caching

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Reset checkbox when a file is changed</issue_title>
<issue_description>Currently, if a file is checked, it remains checked even after it is modified. This behavior is confusing and not consistent with how most code review systems handle file changes.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Reset checkbox when a file is changed #120

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[letmaik]

@copilot rewrite the PR description by comparing against the target branch

[Copilot]

@copilot rewrite the PR description by comparing against the target branch

Updated the PR description to compare against the target branch. Here's the comprehensive summary:

Overview

This PR implements automatic checkbox reset functionality based on file modification time. When enabled, checkboxes automatically reset when a file is modified after being checked, ensuring reviewed status accurately reflects current file state.

Changes

Configuration (package.json)

• Added new config option: gitTreeCompare.resetCheckboxOnFileChange (default: false)
  • When enabled: Resets checkboxes when file mtime > checkbox timestamp
  • When disabled: Checkboxes persist indefinitely

Implementation (src/treeProvider.ts)

New Interface:

interface CheckboxStateInfo {
    state: TreeItemCheckboxState;
    timestamp: number; // When the checkbox was checked
}

Key Changes:

1. Checkbox State Storage: Changed from Map<string, TreeItemCheckboxState> to Map<string, CheckboxStateInfo> to track both state and timestamp

2. Timestamp Capture: Modified handleChangeCheckboxState() to capture Date.now() when checkbox is checked

3. File Modification Time Check: Added async logic in updateDiff() to:

   • Collect all checked files when feature is enabled
   • Use fs.promises.stat() to check file modification times in parallel
   • Reset checkboxes where fileMtime > checkboxTimestamp

4. Performance Optimization:

   • Batch file stat checks with Promise.all() to avoid blocking UI
   • Uses TypeScript type guards for efficient filtering

5. Cleanup Logic: Automatically removes checkbox state for files no longer in diff

Stats

• Files changed: 2
• Lines added: 71
• Lines removed: 3
• Net change: +68 lines

Behavior

When resetCheckboxOnFileChange is enabled:

• User checks file after review → timestamp recorded
• User modifies file → file mtime increases
• On next refresh → checkbox automatically resets if mtime > timestamp

When resetCheckboxOnFileChange is disabled:

• Checkboxes persist indefinitely without automatic reset

Benefits

• Ensures reviewed state reflects actual file content
• Async implementation prevents UI blocking
• Opt-in feature maintains backward compatibility

[letmaik]

@copilot resolve the merge conflicts

[Copilot]

Pull request overview

This PR implements automatic checkbox reset functionality that detects when checked files are modified after review. When enabled via the new resetCheckboxOnFileChange configuration option (default: false), the extension tracks checkbox timestamps and compares them against file modification times to automatically uncheck files that have been modified since review.

Changes:

• Added CheckboxStateInfo interface to track both checkbox state and timestamp
• Implemented file modification time checking using fs.promises.stat() with parallel batch processing
• Added computeFolderCheckboxState method to derive folder checkbox states from child files
• Implemented cleanup logic to remove checkbox states for files no longer in the diff

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 6 comments.

File	Description
package.json	Added resetCheckboxOnFileChange configuration option with description
README.md	Documented the new configuration options (showCheckboxes and resetCheckboxOnFileChange)
src/treeProvider.ts	Implemented core checkbox reset logic with timestamp tracking, file mtime checking, and folder state computation

---

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

[Copilot]

@copilot resolve the merge conflicts

Resolved merge conflicts with master branch in commit b695ab8.

Conflicts Resolved:

1. README.md: Kept both resetCheckboxOnFileChange and refSortOrder documentation
2. package.json: Added both configuration options
3. src/treeProvider.ts: Auto-merged successfully

The code compiles without errors and all functionality is preserved.

[letmaik]

@copilot read through the PR review comments and address them (or ignore them)

[Copilot]

@copilot read through the PR review comments and address them (or ignore them)

Addressed all PR review comments in commit e22bd42:

1. Comment 2724354540: Only set timestamp when checkbox is checked (lines 316-340)
2. Comment 2724354534: Updated comment to clarify timestamp is for checked state (line 22)
3. Comment 2724354520: Changed to >= for mtime comparison to handle race conditions (line 641)
4. Comment 2724354526: Fixed cleanup to track folder paths and not delete folder states (lines 590, 612, 660-670)
5. Comment 2724354543: Consolidated tree refresh to avoid redundancy (lines 579, 644-647, 725)
6. Comment 2724354514: Added caching for computeFolderCheckboxState performance (lines 143, 428-434, 437-439, 462-464, 315, 656, 671)

All changes compile successfully and maintain backward compatibility.