Files
xen-orchestra/@vates/read-chunk/index.test.js
2022-10-24 14:38:56 +02:00

78 lines
2.5 KiB
JavaScript

'use strict'
const { describe, it } = require('test')
const assert = require('node:assert').strict
const { Readable } = require('stream')
const { readChunk, readChunkStrict } = require('./')
const makeStream = it => Readable.from(it, { objectMode: false })
makeStream.obj = Readable.from
describe('readChunk', () => {
it('returns null if stream is empty', async () => {
assert.strictEqual(await readChunk(makeStream([])), null)
})
it('returns null if the stream is already ended', async () => {
const stream = await makeStream([])
await readChunk(stream)
assert.strictEqual(await readChunk(stream), null)
})
describe('with binary stream', () => {
it('returns the first chunk of data', async () => {
assert.deepEqual(await readChunk(makeStream(['foo', 'bar'])), Buffer.from('foo'))
})
it('returns a chunk of the specified size (smaller than first)', async () => {
assert.deepEqual(await readChunk(makeStream(['foo', 'bar']), 2), Buffer.from('fo'))
})
it('returns a chunk of the specified size (larger than first)', async () => {
assert.deepEqual(await readChunk(makeStream(['foo', 'bar']), 4), Buffer.from('foob'))
})
it('returns less data if stream ends', async () => {
assert.deepEqual(await readChunk(makeStream(['foo', 'bar']), 10), Buffer.from('foobar'))
})
it('returns an empty buffer if the specified size is 0', async () => {
assert.deepEqual(await readChunk(makeStream(['foo', 'bar']), 0), Buffer.alloc(0))
})
})
describe('with object stream', () => {
it('returns the first chunk of data verbatim', async () => {
const chunks = [{}, {}]
assert.strictEqual(await readChunk(makeStream.obj(chunks)), chunks[0])
})
})
})
const rejectionOf = promise =>
promise.then(
value => {
throw value
},
error => error
)
describe('readChunkStrict', function () {
it('throws if stream is empty', async () => {
const error = await rejectionOf(readChunkStrict(makeStream([])))
assert(error instanceof Error)
assert.strictEqual(error.message, 'stream has ended without data')
assert.strictEqual(error.chunk, undefined)
})
it('throws if stream ends with not enough data', async () => {
const error = await rejectionOf(readChunkStrict(makeStream(['foo', 'bar']), 10))
assert(error instanceof Error)
assert.strictEqual(error.message, 'stream has ended with not enough data')
assert.deepEqual(error.chunk, Buffer.from('foobar'))
})
})