API Reference

CLI options and programmatic API reference for mdx-formatter

CLI Options

The --ignore patterns are merged with exclude patterns from the config file.

format(content, options?)

Format markdown/MDX content.

• content (string) - Content to format
• options.config (string) - Path to config file
• options.settings (object) - Direct settings overrides (see Options Reference)
• Returns Promise<string> - Formatted content (returns original on error)

The exclude config option is CLI-only. When using the programmatic API (format, formatFile, checkFile), handle file filtering in your own code.

formatFile(filePath, options?)

Format a file and write it back if changed.

• filePath (string) - Path to the file
• options - Same as format()
• Returns Promise<boolean> - true if file was changed

checkFile(filePath, options?)

Check if a file needs formatting without modifying it.

• filePath (string) - Path to the file
• options - Same as format()
• Returns Promise<boolean> - true if file needs formatting

formatSync(content)

Synchronous format with default settings. API-compatible with @takazudo/mdx-formatter-wasm’s format_with_defaults(). Useful for mocking the WASM module in Node.js test environments.

• content (string) - Content to format
• Returns string - Formatted content

import { formatSync } from "@takazudo/mdx-formatter";

const formatted = formatSync("# Hello\nSome text");

Test mock example

vi.mock("@takazudo/mdx-formatter-wasm", async () => {
  const { formatSync } = await import("@takazudo/mdx-formatter");
  return {
    default: async () => {},
    format_with_defaults: formatSync,
  };
});

detectMdx(content)

Check if content is likely MDX (has imports, exports, JSX components, or frontmatter).

• content (string) - Content to check
• Returns boolean