const { lock } = require('proper-lockfile')

const staleSeconds = 30

// Obtains a lock on the path, and maintains it until the callback finishes

function withLock (path, options = {}, callback = options) {

return new Promise(async (resolve, reject) => {

let releaseLock, result

try {

// Obtain the lock

releaseLock = await lock(path, {

retries: 10,

update: 1000,

stale: staleSeconds * 1000,

realpath: !!options.mustExist,

onCompromised: () =>

reject(new Error(`The file at ${path} was not updated within ${staleSeconds}s.`))

})

// Hold on to the lock until the callback's returned promise resolves

result = await callback()

} catch (error) {

reject(error)

// Ensure the lock is always released

} finally {

await releaseLock()

}

resolve(result)

})

}

module.exports = withLock