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\n\n## Usage\n\n### Creating fixtures\n\n**From an object:**\n```ts\nconst fixture = await createFixture({\n 'package.json': '{ \"name\": \"test\" }',\n 'src/index.js': 'export default () => {}',\n 'src/utils': {\n 'helper.js': 'export const help = () => {}'\n }\n})\n```\n\n**From a template directory:**\n```ts\n// Copies an existing directory structure\nconst fixture = await createFixture('./test-templates/basic')\n```\n\n**Empty fixture:**\n```ts\n// Create an empty temporary directory\nconst fixture = await createFixture()\n```\n\n**From an initializer:**\n```ts\nconst fixture = await createFixture(async ({ path, writeJson }) => {\n await writeJson('package.json', {\n name: 'test-package'\n })\n\n // Test-specific setup that needs the fixture path.\n await initializeProject(path)\n\n return {\n 'src/index.js': 'export default 42'\n }\n})\n```\n\nPrefer a `FileTree` when a fixture only needs files and directories. Use an initializer function when setup is complex, imperative, or ordered, such as initializing a Git repository or running a project setup helper. It keeps that setup with the fixture it configures.\n\nThe initializer receives the new fixture before it is returned. It can perform setup directly and optionally return a `FileTree` to create after setup completes. Returned files overwrite regular files created during setup, but the tree does not replace the fixture directory. If setup fails, fs-fixture removes the fixture before it rethrows the error.\n\n### Working with files\n\n`readFile` and `writeFile` inherit their type signatures directly from Node.js `fs/promises`. `readdir` preserves Node.js overloads and also lists the fixture root when called without a path.\n\n**Read files:**\n```ts\n// Read as string (type: Promise