Files
xen-orchestra/@vates/stream-reader/index.test.js
2023-04-12 12:05:55 +02:00

142 lines
4.3 KiB
JavaScript

'use strict'
const { describe, it } = require('test')
const assert = require('node:assert').strict
const { Readable } = require('stream')
const StreamReader = require('./index.js')
const makeStream = it => Readable.from(it, { objectMode: false })
makeStream.obj = Readable.from
const rejectionOf = promise =>
promise.then(
value => {
throw value
},
error => error
)
const makeErrorTests = method => {
it('rejects if the stream errors', async () => {
const error = new Error()
const stream = makeStream([])
const pError = rejectionOf(new StreamReader(stream)[method](10))
stream.destroy(error)
assert.strict(await pError, error)
})
it('rejects if the stream has already errored', async () => {
const error = new Error()
const stream = makeStream([])
await new Promise(resolve => {
stream.once('error', resolve).destroy(error)
})
assert.strict(await rejectionOf(new StreamReader(stream)[method](10)), error)
})
}
describe('read()', () => {
it('rejects if size is less than or equal to 0', async () => {
const error = await rejectionOf(new StreamReader(makeStream([])).read(0))
assert.strictEqual(error.code, 'ERR_ASSERTION')
})
it('returns null if stream is empty', async () => {
assert.strictEqual(await new StreamReader(makeStream([])).read(), null)
})
makeErrorTests('read')
it('returns null if the stream is already ended', async () => {
const reader = new StreamReader(makeStream([]))
await reader.read()
assert.strictEqual(await reader.read(), null)
})
describe('with binary stream', () => {
it('returns the first chunk of data', async () => {
assert.deepEqual(await new StreamReader(makeStream(['foo', 'bar'])).read(), Buffer.from('foo'))
})
it('returns a chunk of the specified size (smaller than first)', async () => {
assert.deepEqual(await new StreamReader(makeStream(['foo', 'bar'])).read(2), Buffer.from('fo'))
})
it('returns a chunk of the specified size (larger than first)', async () => {
assert.deepEqual(await new StreamReader(makeStream(['foo', 'bar'])).read(4), Buffer.from('foob'))
})
it('returns less data if stream ends', async () => {
assert.deepEqual(await new StreamReader(makeStream(['foo', 'bar'])).read(10), Buffer.from('foobar'))
})
})
describe('with object stream', () => {
it('returns the first chunk of data verbatim', async () => {
const chunks = [{}, {}]
assert.strictEqual(await new StreamReader(makeStream.obj(chunks)).read(), chunks[0])
})
})
})
describe('readStrict()', function () {
it('throws if stream is empty', async () => {
const error = await rejectionOf(new StreamReader(makeStream([])).readStrict())
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(new StreamReader(makeStream(['foo', 'bar'])).readStrict(10))
assert(error instanceof Error)
assert.strictEqual(error.message, 'stream has ended with not enough data (actual: 6, expected: 10)')
assert.deepEqual(error.chunk, Buffer.from('foobar'))
})
})
describe('skip()', function () {
makeErrorTests('skip')
it('returns 0 if size is 0', async () => {
assert.strictEqual(await new StreamReader(makeStream(['foo'])).skip(0), 0)
})
it('returns 0 if the stream is already ended', async () => {
const reader = new StreamReader(makeStream([]))
await reader.read()
assert.strictEqual(await reader.skip(10), 0)
})
it('skips a number of bytes', async () => {
const reader = new StreamReader(makeStream('foo bar'))
assert.strictEqual(await reader.skip(4), 4)
assert.deepEqual(await reader.read(4), Buffer.from('bar'))
})
it('returns less size if stream ends', async () => {
assert.deepEqual(await new StreamReader(makeStream('foo bar')).skip(10), 7)
})
})
describe('skipStrict()', function () {
it('throws if stream ends with not enough data', async () => {
const error = await rejectionOf(new StreamReader(makeStream('foo bar')).skipStrict(10))
assert(error instanceof Error)
assert.strictEqual(error.message, 'stream has ended with not enough data (actual: 7, expected: 10)')
assert.deepEqual(error.bytesSkipped, 7)
})
})