Function renderDiffContent

packages/cli/src/ui/components/messages/DiffRenderer.tsx:168–338

(
  parsedLines: DiffLine[],
  filename: string | undefined,
  tabWidth = DEFAULT_TAB_WIDTH,
  availableTerminalHeight: number | undefined,
  terminalWidth: number,
)

};

const renderDiffContent = (
  parsedLines: DiffLine[],
  filename: string | undefined,
  tabWidth = DEFAULT_TAB_WIDTH,
  availableTerminalHeight: number | undefined,
  terminalWidth: number,
) => {
  // 1. Normalize whitespace (replace tabs with spaces) *before* further processing
  const normalizedLines = parsedLines.map((line) => ({
    ...line,
    content: line.content.replace(/\t/g, ' '.repeat(tabWidth)),
  }));

  // Filter out non-displayable lines (hunks, potentially 'other') using the normalized list
  const displayableLines = normalizedLines.filter(
    (l) => l.type !== 'hunk' && l.type !== 'other',
  );

  if (displayableLines.length === 0) {
    return (
      <Box borderStyle="round" borderColor={Colors.Gray} padding={1}>
        <Text dimColor>No changes detected.</Text>
      </Box>
    );
  }

  const maxLineNumber = Math.max(
    0,
    ...displayableLines.map((l) => l.oldLine ?? 0),
    ...displayableLines.map((l) => l.newLine ?? 0),
  );
  const gutterWidth = Math.max(1, maxLineNumber.toString().length);

  const fileExtension = filename?.split('.').pop() || null;
  const language = fileExtension
    ? getLanguageFromExtension(fileExtension)
    : null;

  // Calculate the minimum indentation across all displayable lines
  let baseIndentation = Infinity; // Start high to find the minimum
  for (const line of displayableLines) {
    // Only consider lines with actual content for indentation calculation
    if (line.content.trim() === '') continue;

    const firstCharIndex = line.content.search(/\S/); // Find index of first non-whitespace char
    const currentIndent = firstCharIndex === -1 ? 0 : firstCharIndex; // Indent is 0 if no non-whitespace found
    baseIndentation = Math.min(baseIndentation, currentIndent);
  }
  // If baseIndentation remained Infinity (e.g., no displayable lines with content), default to 0
  if (!isFinite(baseIndentation)) {
    baseIndentation = 0;
  }

  const key = filename
    ? `diff-box-${filename}`
    : `diff-box-${crypto.createHash('sha1').update(JSON.stringify(parsedLines)).digest('hex')}`;

  let lastLineNumber: number | null = null;