Since Frisby.js is based on the Fetch API, file uploads are a cinch with the built-in FormData object (see Using FormData Objects on MDN if you are not familiar with them).
You can get a new FormData object from Frisby:
let formData = frisby.formData();
A full usage example might look like this:
const csvPath = path.resolve(__dirname, './file.csv');let content = fs.createReadStream(csvPath);let formData = frisby.formData();formData.append('file', content);return frisby.post('http://api.example.com/files', { body: formData }).inspectRequestHeaders().expect('status', 200)