[tranphucbol]

1. Purpose & Motivation

Description

Refs #6

39b8aac removed the three-way merge editor. Without it, conflicts can only be resolved in the standard VS Code editor with conflict markers. As agreed in #6, this PR brings the editor back as an opt-in feature behind intelli-git.mergeEditor.enabled, which defaults to false.

The PR is a plain git revert of 39b8aac, so the restored code matches what was removed and can be reviewed against it. The follow-ups from #6 are left for a separate PR so this diff stays a clean revert: loading Monaco only in the resolver's own webview, and rewording the conflict section of AGENTS.md for the opt-in setting.

Context & Flow

Click conflict file in Commit view
      │
      ├── [OLD] rpc.openFile() → standard VS Code editor with conflict markers
      │
      └── [NEW] rpc.openConflictResolver() → openConflictFile()
                  │
                  ├── mergeEditor.enabled = false (default)
                  │       └── vscode.open → standard VS Code editor (same as today)
                  │
                  └── mergeEditor.enabled = true
                          └── ConflictResolverPanel (editor-area webview, one per file)
                                  │
                                  ├── getConflictFileContent → git index stages 1/2/3 + worktree result
                                  │
                                  ├── Accept Left / Accept Right → resolveConflict → git add
                                  │
                                  └── Apply → saveConflictResolution
                                          ├── stage signature or result changed → reject, panel stays open
                                          └── unchanged → write result, git add, refresh Commit view

2. Verification & Testing

Provide reproducible inputs or steps for each test case, followed by the result and supporting evidence.

• npm run compile, npm run lint and npm run test pass on the branch

  Compile and lint pass, including the webview l10n audit (69 files, 329 keys). Tests: 219 extension tests and 109 webview tests pass.

• With intelli-git.mergeEditor.enabled on, clicking a conflict file opens the three-way editor in the editor area

  Extension Development Host with the merge-conflict fixture (UU, UD, DU, AA). Clicking multiple-conflicts.txt opens Merge: multiple-conflicts.txt with 8 unresolved changes.

  

• With the setting on, a delete/modify conflict shows which side deleted the file

  delete-on-feature.txt (UD) shows the incoming side as deleted, and the footer offers Accept Right (delete file).

  

• With the setting on, Accept Left resolves and stages the file

  Accept Left on src/conflict.txt closes the panel, stages the file with the current-branch content, and the Conflicting Changes count drops from 5 to 4.

  

• With the setting off (default), clicking a conflict file opens the standard VS Code editor

  multiple-conflicts.txt opens in the standard text editor with conflict markers and the built-in CodeLens actions, same as current main.

  

[boyan01]

Thanks for restoring it and for the thorough before/after evidence! Merged.