DefinitelyTyped/types/keytar/keytar-tests.ts

import keytar = require('keytar');

let setResult: Promise<void>;
setResult = keytar.setPassword('keytar-tests', 'username', 'password');

let success: Promise<boolean>;
success = keytar.deletePassword('keytar-tests', 'username');

let password: Promise<string | null>;
password = keytar.findPassword('keytar-tests');
password = keytar.getPassword('keytar-tests', 'username');

let credentials: Promise<Array<{ account: string, password: string }>>;
credentials = keytar.findCredentials('keytar-tests');