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management/front/dkha-web-sz-main/node_modules/map-stream/test/simple-map.asynct.js

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JavaScript
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2023-12-18 13:12:25 +08:00
'use strict';
var map = require('../')
, it = require('it-is')
, u = require('ubelt')
, spec = require('stream-spec')
, from = require('from')
, Stream = require('stream')
, es = require('event-stream')
//REFACTOR THIS TEST TO USE es.readArray and es.writeArray
function writeArray(array, stream) {
array.forEach( function (j) {
stream.write(j)
})
stream.end()
}
function readStream(stream, done) {
var array = []
stream.on('data', function (data) {
array.push(data)
})
stream.on('error', done)
stream.on('end', function (data) {
done(null, array)
})
}
//call sink on each write,
//and complete when finished.
function pauseStream (prob, delay) {
var pauseIf = (
'number' == typeof prob
? function () {
return Math.random() < prob
}
: 'function' == typeof prob
? prob
: 0.1
)
var delayer = (
!delay
? process.nextTick
: 'number' == typeof delay
? function (next) { setTimeout(next, delay) }
: delay
)
return es.through(function (data) {
if(!this.paused && pauseIf()) {
console.log('PAUSE STREAM PAUSING')
this.pause()
var self = this
delayer(function () {
console.log('PAUSE STREAM RESUMING')
self.resume()
})
}
console.log("emit ('data', " + data + ')')
this.emit('data', data)
})
}
exports ['simple map applied to a stream'] = function (test) {
var input = [1,2,3,7,5,3,1,9,0,2,4,6]
//create event stream from
var doubler = map(function (data, cb) {
cb(null, data * 2)
})
spec(doubler).through().validateOnExit()
//a map is only a middle man, so it is both readable and writable
it(doubler).has({
readable: true,
writable: true,
})
readStream(doubler, function (err, output) {
it(output).deepEqual(input.map(function (j) {
return j * 2
}))
// process.nextTick(x.validate)
test.done()
})
writeArray(input, doubler)
}
exports ['stream comes back in the correct order'] = function (test) {
var input = [3, 2, 1]
var delayer = map(function(data, cb){
setTimeout(function () {
cb(null, data)
}, 100 * data)
})
readStream(delayer, function (err, output) {
it(output).deepEqual(input)
test.done()
})
writeArray(input, delayer)
}
exports['pipe two maps together'] = function (test) {
var input = [1,2,3,7,5,3,1,9,0,2,4,6]
//create event stream from
function dd (data, cb) {
cb(null, data * 2)
}
var doubler1 = map(dd), doubler2 = map(dd)
doubler1.pipe(doubler2)
spec(doubler1).through().validateOnExit()
spec(doubler2).through().validateOnExit()
readStream(doubler2, function (err, output) {
it(output).deepEqual(input.map(function (j) {
return j * 4
}))
test.done()
})
writeArray(input, doubler1)
}
//next:
//
// test pause, resume and drian.
//
// then make a pipe joiner:
//
// plumber (evStr1, evStr2, evStr3, evStr4, evStr5)
//
// will return a single stream that write goes to the first
exports ['map will not call end until the callback'] = function (test) {
var ticker = map(function (data, cb) {
process.nextTick(function () {
cb(null, data * 2)
})
})
spec(ticker).through().validateOnExit()
ticker.write('x')
ticker.end()
ticker.on('end', function () {
test.done()
})
}
exports ['emit error thrown'] = function (test) {
var err = new Error('INTENSIONAL ERROR')
, mapper =
map(function () {
throw err
})
mapper.on('error', function (_err) {
it(_err).equal(err)
test.done()
})
mapper.write('hello')
}
exports ['emit error calledback'] = function (test) {
var err = new Error('INTENSIONAL ERROR')
, mapper =
map(function (data, callback) {
callback(err)
})
mapper.on('error', function (_err) {
it(_err).equal(err)
test.done()
})
mapper.write('hello')
}
exports ['do not emit drain if not paused'] = function (test) {
var maps = map(function (data, callback) {
u.delay(callback)(null, 1)
return true
})
spec(maps).through().pausable().validateOnExit()
maps.on('drain', function () {
it(false).ok('should not emit drain unless the stream is paused')
})
it(maps.write('hello')).equal(true)
it(maps.write('hello')).equal(true)
it(maps.write('hello')).equal(true)
setTimeout(function () {maps.end()},10)
maps.on('end', test.done)
}
exports ['emits drain if paused, when all '] = function (test) {
var active = 0
var drained = false
var maps = map(function (data, callback) {
active ++
u.delay(function () {
active --
callback(null, 1)
})()
console.log('WRITE', false)
return false
})
spec(maps).through().validateOnExit()
maps.on('drain', function () {
drained = true
it(active).equal(0, 'should emit drain when all maps are done')
})
it(maps.write('hello')).equal(false)
it(maps.write('hello')).equal(false)
it(maps.write('hello')).equal(false)
process.nextTick(function () {maps.end()},10)
maps.on('end', function () {
console.log('end')
it(drained).ok('shoud have emitted drain before end')
test.done()
})
}
exports ['map applied to a stream with filtering'] = function (test) {
var input = [1,2,3,7,5,3,1,9,0,2,4,6]
var doubler = map(function (data, callback) {
if (data % 2)
callback(null, data * 2)
else
callback()
})
readStream(doubler, function (err, output) {
it(output).deepEqual(input.filter(function (j) {
return j % 2
}).map(function (j) {
return j * 2
}))
test.done()
})
spec(doubler).through().validateOnExit()
writeArray(input, doubler)
}