Function makeStackCell

src/ui/diff/pierre.ts:489–521

Build the normalized render model for one stack-view cell.

(
  kind: StackLineCell["kind"],
  oldLineNumber: number | undefined,
  newLineNumber: number | undefined,
  rawLine: string | undefined,
  highlightedLine: HastNode | undefined,
  theme: AppTheme,
  moveKind?: DiffLineMoveKind,
)

/** Build the normalized render model for one stack-view cell. */
function makeStackCell(
  kind: StackLineCell["kind"],
  oldLineNumber: number | undefined,
  newLineNumber: number | undefined,
  rawLine: string | undefined,
  highlightedLine: HastNode | undefined,
  theme: AppTheme,
  moveKind?: DiffLineMoveKind,
) {
  // Same lazy-fallback strategy as split cells: only normalize the raw source line when we really
  // need the plain-text fallback, not when highlighted spans are already ready to reuse.
  let spans: RenderSpan[];
  if (highlightedLine === undefined) {
    const fallbackText = cleanDiffLine(rawLine);
    spans = fallbackText.length > 0 ? [{ text: fallbackText }] : [];
  } else {
    spans = flattenHighlightedLine(highlightedLine, theme, wordDiffHighlightBg(kind, theme));

    if (spans.length === 0) {
      const fallbackText = cleanDiffLine(rawLine);
      spans = fallbackText.length > 0 ? [{ text: fallbackText }] : [];
    }
  }

  return {
    kind,
    sign: kind === "addition" ? "+" : kind === "deletion" ? "-" : " ",
    oldLineNumber,
    newLineNumber,
    moveKind,
    spans,
  } satisfies StackLineCell;
}

/** Describe one collapsed unchanged region in the diff stream. */
function collapsedRowText(lines: number) {