Diff viewer¶

The diff viewer is the core review surface. Open it by pressing 2 from any MR detail view to switch to the Diff tab.

Layout¶

The diff viewer uses a split-pane layout:

Left pane -- file tree showing all changed files with status indicators (M modified, A added, D deleted, R renamed)
Right pane -- the diff content for the selected file, with syntax highlighting, line numbers, and gutter markers

Key	Action
`N`	Jump to the next file
`Shift`+`N`	Jump to the previous file

You can also click any file in the file tree to jump directly to it.

Key	Action
`J`	Move cursor down one line
`K`	Move cursor up one line

The cursor highlights the active line and updates the gutter indicator.

Visual line selection¶

Select multiple lines for multi-line comments:

Key	Action
`Shift`+`J`	Extend selection down
`Shift`+`K`	Extend selection up
`Ctrl` + click	Extend selection to clicked line
`Esc`	Clear selection

Truncated diffs¶

When a forge API truncates a large diff (returning no patch content), the file still appears in the file tree with its +/- stats. The diff pane shows a "Diff not available" message with a prompt to press O to view the full file in your browser.

Syntax highlighting¶

tongs uses Pygments to apply syntax highlighting to 500+ languages. All lines in a file are highlighted in a single bulk Pygments call for performance, rather than per-line.

Word-level diffs¶

Within modified lines, tongs highlights the specific words that changed using bold and underline styling. This makes it easy to spot small changes in long lines without reading the entire line.

Context folding¶

Long unchanged sections between changes are collapsed into a marker showing how many lines were hidden (for example, "... 42 unchanged lines ..."). This keeps the diff focused on what actually changed.

Markdown preview¶

For .md files, press M to toggle between the raw diff and a rendered Markdown preview.

Inline comments in the diff¶

Existing discussion threads appear as gutter markers next to the relevant lines in the diff. Press D on a line with a marker to expand or collapse the thread. Press [ and ] to jump between comments.

Adding a comment¶

Navigate to the line (or select multiple lines) where you want to comment
Press C to open the comment editor at the bottom of the screen
Write your comment
Press Ctrl+S to submit, or Esc to cancel

Suggesting changes¶

Select the lines you want to suggest a replacement for
Press F3 to open your $EDITOR with the selected code pre-filled
Edit the code to show your suggested replacement
Save and close the editor
tongs posts the suggestion using the forge's native suggestion syntax (GitHub ```suggestion / GitLab ```suggestion:-0+N)

External editor¶

Press F2 inside the comment editor to switch to your preferred external editor. The comment text is transferred to the editor and back when you save and close.