Function resolveWordDiffHighlightBg

src/ui/diff/pierre.ts:289–301

Resolve one word-diff background without turning transparent surfaces into black blends.

(contentBg: string, lineBg: string, signColor: string)

/** Resolve one word-diff background without turning transparent surfaces into black blends. */
function resolveWordDiffHighlightBg(contentBg: string, lineBg: string, signColor: string) {
  if (contentBg === TRANSPARENT_BACKGROUND || lineBg === TRANSPARENT_BACKGROUND) {
    return contentBg;
  }

  if (!isHexThemeColor(contentBg) || !isHexThemeColor(lineBg)) {
    return contentBg;
  }

  return hexColorDistance(contentBg, lineBg) >= MIN_WORD_DIFF_BG_DISTANCE
    ? contentBg
    : strengthenWordDiffBg(lineBg, signColor);
}

/** Resolve the inline word-diff background, strengthening theme colors that are too subtle to see. */
function wordDiffHighlightBg(kind: SplitLineCell["kind"], theme: AppTheme) {