Function CodeComponent

packages/streamdown/lib/components.tsx:778–957

({
  node,
  className,
  children,
  ...props
}: DetailedHTMLProps<HTMLAttributes<HTMLElement>, HTMLElement> &
  // biome-ignore lint/complexity/noExcessiveCognitiveComplexity: "Code component handles multiple rendering paths for inline code, code blocks, and mermaid diagrams"
  ExtraProps & { "data-block"?: string })

MemoSection.displayName = "MarkdownSection";

const CodeComponent = ({
  node,
  className,
  children,
  ...props
}: DetailedHTMLProps<HTMLAttributes<HTMLElement>, HTMLElement> &
  // biome-ignore lint/complexity/noExcessiveCognitiveComplexity: "Code component handles multiple rendering paths for inline code, code blocks, and mermaid diagrams"
  ExtraProps & { "data-block"?: string }) => {
  const cn = useCn();
  // A code element is block-level when it was inside a <pre> element.
  // The custom pre component marks its children with data-block.
  const inline = !("data-block" in props);
  const {
    mermaid: mermaidContext,
    controls: controlsConfig,
    lineNumbers: contextLineNumbers,
  } = useContext(StreamdownContext);
  const mermaidPlugin = useMermaidPlugin();
  const isBlockIncomplete = useIsCodeFenceIncomplete();

  const match = className?.match(LANGUAGE_REGEX);
  const language = match?.at(1) ?? "";
  const customRenderer = useCustomRenderer(language);

  if (inline) {
    return (
      <code
        className={cn(
          "rounded bg-muted px-1.5 py-0.5 font-mono text-sm",
          className
        )}
        data-streamdown="inline-code"
        {...props}
      >
        {children}
      </code>
    );
  }

  // Parse startLine from the code fence meta string (e.g. ```js startLine=10)
  const metastring = node?.properties?.metastring;
  const startLineMatch = metastring?.match(START_LINE_PATTERN);
  const parsedStartLine = startLineMatch
    ? Number.parseInt(startLineMatch[1], 10)
    : undefined;
  const startLine =
    parsedStartLine !== undefined && parsedStartLine >= 1
      ? parsedStartLine
      : undefined;

  // Parse noLineNumbers from meta string and derive effective lineNumbers
  const metaNoLineNumbers = metastring
    ? NO_LINE_NUMBERS_PATTERN.test(metastring)
    : false;
  const showLineNumbers = !metaNoLineNumbers && contextLineNumbers !== false;

  // Extract code content from children safely
  let code = "";