# babel-generator > Turns an AST into code. ## Install ```sh $ npm install babel-generator ``` ## Usage ```js import {parse} from 'babylon'; import generate from 'babel-generator'; const code = 'class Example {}'; const ast = parse(code); const output = generate(ast, { /* options */ }, code); ``` ## Options Options for formatting output: name | type | default | description -----------------------|----------|-----------------|-------------------------------------------------------------------------- auxiliaryCommentBefore | string | | Optional string to add as a block comment at the start of the output file auxiliaryCommentAfter | string | | Optional string to add as a block comment at the end of the output file shouldPrintComment | function | `opts.comments` | Function that takes a comment (as a string) and returns `true` if the comment should be included in the output. By default, comments are included if `opts.comments` is `true` or if `opts.minifed` is `false` and the comment contains `@preserve` or `@license` retainLines | boolean | `false` | Attempt to use the same line numbers in the output code as in the source code (helps preserve stack traces) comments | boolean | `true` | Should comments be included in output compact | boolean or `'auto'` | `opts.minified` | Set to `true` to avoid adding whitespace for formatting minified | boolean | `false` | Should the output be minified concise | boolean | `false` | Set to `true` to reduce whitespace (but not as much as `opts.compact`) quotes | `'single'` or `'double'` | autodetect based on `ast.tokens` | The type of quote to use in the output filename | string | | Used in warning messages Options for source maps: name | type | default | description -----------------------|----------|-----------------|-------------------------------------------------------------------------- sourceMaps | boolean | `false` | Enable generating source maps sourceMapTarget | string | | The filename of the generated code that the source map will be associated with sourceRoot | string | | A root for all relative URLs in the source map sourceFileName | string | | The filename for the source code (i.e. the code in the `code` argument)