Laca-City/backend/node_modules/@ljharb/through/test/index.js

'use strict';

var test = require('tape');
var spec = require('stream-spec');
var through = require('../');

/*
 *I'm using these two functions, and not streams and pipe
 *so there is less to break. if this test fails it must be
 *the implementation of _through_
 */

function write(array, stream) {
	array = array.slice();
	function next() {
		while (array.length) { if (stream.write(array.shift()) === false) { return stream.once('drain', next); } }

		stream.end();
	}

	next();
}

function read(stream, callback) {
	var actual = [];
	stream.on('data', function (data) {
		actual.push(data);
	});
	stream.once('end', function () {
		callback(null, actual);
	});
	stream.once('error', function (err) {
		callback(err);
	});
}

test('simple defaults', function (assert) {
	var l = 1000;
	var expected = [];

	while (l--) { expected.push(l * Math.random()); }

	var t = through();
	var s = spec(t).through().pausable();

	read(t, function (err, actual) {
		assert.ifError(err);
		assert.deepEqual(actual, expected);
		assert.end();
	});

	t.on('close', s.validate);

	write(expected, t);
});

test('simple functions', function (assert) {
	var l = 1000;
	var expected = [];

	while (l--) { expected.push(l * Math.random()); }

	var t = through(function (data) {
		this.emit('data', data * 2);
	});
	var s = spec(t).through().pausable();

	read(t, function (err, actual) {
		assert.ifError(err);
		assert.deepEqual(actual, expected.map(function (data) {
			return data * 2;
		}));
		assert.end();
	});

	t.on('close', s.validate);

	write(expected, t);
});

test('pauses twice', function (t) {
	var ts = through();

	t.equal(ts.pause(), ts, 'when pausing, returns stream');
	t.equal(ts.pause(), undefined, 'when already paused, returns void');

	t.end();
});

test('pauses', function (assert) {
	var l = 1000;
	var expected = [];

	while (l--) { expected.push(l); } // Math.random())

	var t = through();

	var s = spec(t)
		.through()
		.pausable();

	t.on('data', function () {
		if (Math.random() > 0.1) { return; }
		t.pause();
		process.nextTick(function () {
			t.resume();
		});
	});

	read(t, function (err, actual) {
		assert.ifError(err);
		assert.deepEqual(actual, expected);
	});

	t.on('close', function () {
		s.validate();
		assert.end();
	});

	write(expected, t);
});

test('does not soft-end on `undefined`', function (assert) {
	var stream = through();
	var count = 0;

	stream.on('data', function () {
		count += 1;
	});

	stream.write(undefined);
	stream.write(undefined);

	assert.equal(count, 2);

	assert.end();
});