writeFile

Write data to a file, replacing the file if it exists. Supports encodings, mode, and flag.

Basic usage


import { writeFile } from '@rush-fs/core'
 
await writeFile('./out.txt', 'hello world')
await writeFile('./out.bin', buffer)
await writeFile('./out.txt', 'content', { encoding: 'utf8', mode: 0o644 })

Methods

`writeFile(path, data, options?)`

Async. Returns Promise<void>.

Argument	Type	Description
`path`	string	File path.
`data`	string \| Buffer	Data to write.
`options`	object	Optional. See below.

Options: encoding (utf8, ascii, latin1, base64, base64url, hex), mode (number), flag (e.g. 'w', 'wx', 'a', 'ax').

`writeFileSync(path, data, options?)`

Sync. Same arguments; throws on error.

Performance

From repo benchmarks (pnpm build && pnpm bench):

Scenario	Node.js	Rush-FS	Ratio
writeFile small (string)	74 µs	66 µs	0.9x
writeFile small (Buffer)	115 µs	103 µs	0.9x
writeFile 4 MB string	2.93 ms	5.69 ms	Node.js faster (large string over N-API)

Single-file writes are on par with Node.js for small payloads; for very large strings Node.js can be faster due to N-API copy cost.

Notes

Encodings: Same as Node.js (utf8, ascii, latin1, base64, base64url, hex).
Large data: Writing a very large string (e.g. 4 MB) crosses the N-API boundary and can be slower than Node.js; prefer Buffer for large binary data where possible.