Expose line number information to custom command templates #4677

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1. cappyzawa

   added

   enhancementNew feature or requestNew feature or request

   on Jul 2, 2025
2. KennethHoff commented on Aug 6, 2026

   

   KennethHoff

   on Aug 6, 2026

   More actions

   This comment extends #4677's original ask beyond a single-line cursor position to also expose range-selection information to custom command templates. Everything below is traced from source only, pinned to commit bd76666 on master (current release v0.64.0) — I haven't run these code paths live, only read them.

   The original issue requests {{.CurrentLineNumber}} for diff-browsing contexts like staging, which is valuable for automating line-level operations. Alongside that, the staging and patch-building panels also support visual-mode range selection (v, extendable with shift+arrow keys, or a plain mouse drag), and exposing that selection's bounds would unlock range-based commands — exactly as {{.SelectedCommitRange}} already does for ranged commit selection (PR #4204).

   Tracing the source, the necessary machinery already exists in the codebase, simply not wired into the custom command template system. The SessionState struct (pkg/gui/services/custom_commands/session_state_loader.go lines 195–213) holds the fields that become {{.SelectedX}} template variables and includes SelectedCommitRange *CommitRange (line 200), but nothing equivalent for diffs. SessionStateLoader.call() (starting line 215, body running to its return at lines 240–258) populates SessionState entirely by reading list-based contexts — Files, Branches, Commits, etc. — and never touches the diff-browsing contexts: Staging, StagingSecondary, or CustomPatchBuilder.

   Those three contexts are all constructed via NewPatchExplorerContext(...) (pkg/gui/context/setup.go lines 44–74), which surfaces selection state through PatchExplorerContext.GetState() *patch_exploring.State (pkg/gui/context/patch_explorer_context.go). The State type (pkg/gui/patch_exploring/state.go) already exposes both halves of this ask: CurrentLineNumber() (lines 389–391) returns the single-cursor file line number, and SelectedViewRange() / SelectedPatchRange() (lines 353, 370) return the bounds of the current selection as (start, end) indices — these work across all select modes (line, hunk, and range), not just an active range. File line numbers are mapped from patch indices via Patch.LineNumberOfLine(idx int) (pkg/commands/patch/patch.go line 92).

   One way to close this gap: add {{.CurrentLineNumber}} (int) to satisfy the original ask, and {{.SelectedLineRange}} with .From/.To fields (both file line numbers, as ints) mirroring SelectedCommitRange's existing .To/.From shape from PR #4204. When no range is active, .From and .To would both equal CurrentLineNumber, matching how a single selected commit already degenerates for SelectedCommitRange. Populate these only in the Staging, StagingSecondary, and CustomPatchBuilder contexts, and leave them unset elsewhere — as the original issue already proposed for its narrower scope. The file path for these lines is already available via the existing {{.SelectedFile.Name}}, {{.SelectedPath}}, or {{.SelectedCommitFilePath}} fields, so no new field is needed there.

   This project doesn't accept pull requests (per CONTRIBUTING.md), so this stays a discussion topic for your design rather than a code contribution.

   ---

   Drafted with AI Assistance and reviewed by the reporter before posting.
3. nat-e commented on Sep 1, 2026

   

   nat-e

   on Sep 1, 2026

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   I'm using Lazygit to review LLM changes before opening PRs and would find this super useful so that I could add comments directly through lg via a custom command

   customCommands:
     - key: 'n'
       context: 'files, staging'
       description: 'Add review note'
       prompts:
         - type: 'input'
           title: 'Review comment'
           key: 'Comment'
       command: >
         jq -nc --arg f {{.SelectedFile.Name | quote}}
         --arg c {{.Form.Comment | quote}}
         '{file:$f, comment:$c, ts:(now|todate)}'
         >> .git/review-notes.jsonl
       loadingText: 'Saving note'
       output: none
4. jozefRudy commented on Oct 31, 2026

   

   jozefRudy

   on Oct 31, 2026

   More actions

   Extending this to the commit-files diff view, which the staging/patch contexts above don't cover.

   There, editAtLine resolves the diff line against the worktree copy of the file (EditFileOfDiffAtLine → existingPathInWorktreeOfDiff), so external tools cannot open the file as it exists in the selected commit. A custom command could, if it knew the selected line.

   Minimal shape, using what already exists:

   • add SelectedLine (1-based view line), SelectedLineContent, and SelectedFileLine (only where a mapping exists) to SessionState in pkg/gui/services/custom_commands/session_state_loader.go, populated in call() from the focused context's view (ViewTrait.SelectedLineIdx() / SelectedLine())
   • reuse DiffHelper.AdjustLineNumber(path, lineIndex+1, viewName) for the file line — the same call editAtLine already makes
   • document that in a diff the view line includes hunk headers and +/- markers, which is why both values are useful

   SelectedLineContent is what makes arbitrary revisions work without diff math: a custom command can locate that text in git show <rev>:<path>, so hunk offsets don't matter and lazygit needs no knowledge of old files, revisions, or diff direction. It also lets line-scoped commands work outside diffs, where a file line is not tracked at all.

   Concrete use case: opening a file at the selected commit and its parent at the same place, side by side in an external editor.