nodejs/test/parallel/test-stream2-transform.js

473 lines
12 KiB
JavaScript

// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.
'use strict';
const common = require('../common');
const assert = require('assert');
const PassThrough = require('_stream_passthrough');
const Transform = require('_stream_transform');
{
// Verify writable side consumption
const tx = new Transform({
highWaterMark: 10
});
let transformed = 0;
tx._transform = function(chunk, encoding, cb) {
transformed += chunk.length;
tx.push(chunk);
cb();
};
for (let i = 1; i <= 10; i++) {
tx.write(Buffer.allocUnsafe(i));
}
tx.end();
assert.strictEqual(tx.readableLength, 10);
assert.strictEqual(transformed, 10);
assert.strictEqual(tx._transformState.writechunk.length, 5);
assert.deepStrictEqual(tx.writableBuffer.map(function(c) {
return c.chunk.length;
}), [6, 7, 8, 9, 10]);
}
{
// Verify passthrough behavior
const pt = new PassThrough();
pt.write(Buffer.from('foog'));
pt.write(Buffer.from('bark'));
pt.write(Buffer.from('bazy'));
pt.write(Buffer.from('kuel'));
pt.end();
assert.strictEqual(pt.read(5).toString(), 'foogb');
assert.strictEqual(pt.read(5).toString(), 'arkba');
assert.strictEqual(pt.read(5).toString(), 'zykue');
assert.strictEqual(pt.read(5).toString(), 'l');
}
{
// Verify object passthrough behavior
const pt = new PassThrough({ objectMode: true });
pt.write(1);
pt.write(true);
pt.write(false);
pt.write(0);
pt.write('foo');
pt.write('');
pt.write({ a: 'b' });
pt.end();
assert.strictEqual(pt.read(), 1);
assert.strictEqual(pt.read(), true);
assert.strictEqual(pt.read(), false);
assert.strictEqual(pt.read(), 0);
assert.strictEqual(pt.read(), 'foo');
assert.strictEqual(pt.read(), '');
assert.deepStrictEqual(pt.read(), { a: 'b' });
}
{
// Verify passthrough constructor behavior
const pt = PassThrough();
assert(pt instanceof PassThrough);
}
{
// Verify transform constructor behavior
const pt = Transform();
assert(pt instanceof Transform);
}
{
// Perform a simple transform
const pt = new Transform();
pt._transform = function(c, e, cb) {
const ret = Buffer.alloc(c.length, 'x');
pt.push(ret);
cb();
};
pt.write(Buffer.from('foog'));
pt.write(Buffer.from('bark'));
pt.write(Buffer.from('bazy'));
pt.write(Buffer.from('kuel'));
pt.end();
assert.strictEqual(pt.read(5).toString(), 'xxxxx');
assert.strictEqual(pt.read(5).toString(), 'xxxxx');
assert.strictEqual(pt.read(5).toString(), 'xxxxx');
assert.strictEqual(pt.read(5).toString(), 'x');
}
{
// Verify simple object transform
const pt = new Transform({ objectMode: true });
pt._transform = function(c, e, cb) {
pt.push(JSON.stringify(c));
cb();
};
pt.write(1);
pt.write(true);
pt.write(false);
pt.write(0);
pt.write('foo');
pt.write('');
pt.write({ a: 'b' });
pt.end();
assert.strictEqual(pt.read(), '1');
assert.strictEqual(pt.read(), 'true');
assert.strictEqual(pt.read(), 'false');
assert.strictEqual(pt.read(), '0');
assert.strictEqual(pt.read(), '"foo"');
assert.strictEqual(pt.read(), '""');
assert.strictEqual(pt.read(), '{"a":"b"}');
}
{
// Verify async passthrough
const pt = new Transform();
pt._transform = function(chunk, encoding, cb) {
setTimeout(function() {
pt.push(chunk);
cb();
}, 10);
};
pt.write(Buffer.from('foog'));
pt.write(Buffer.from('bark'));
pt.write(Buffer.from('bazy'));
pt.write(Buffer.from('kuel'));
pt.end();
pt.on('finish', common.mustCall(function() {
assert.strictEqual(pt.read(5).toString(), 'foogb');
assert.strictEqual(pt.read(5).toString(), 'arkba');
assert.strictEqual(pt.read(5).toString(), 'zykue');
assert.strictEqual(pt.read(5).toString(), 'l');
}));
}
{
// Verify asymmetric transform (expand)
const pt = new Transform();
// Emit each chunk 2 times.
pt._transform = function(chunk, encoding, cb) {
setTimeout(function() {
pt.push(chunk);
setTimeout(function() {
pt.push(chunk);
cb();
}, 10);
}, 10);
};
pt.write(Buffer.from('foog'));
pt.write(Buffer.from('bark'));
pt.write(Buffer.from('bazy'));
pt.write(Buffer.from('kuel'));
pt.end();
pt.on('finish', common.mustCall(function() {
assert.strictEqual(pt.read(5).toString(), 'foogf');
assert.strictEqual(pt.read(5).toString(), 'oogba');
assert.strictEqual(pt.read(5).toString(), 'rkbar');
assert.strictEqual(pt.read(5).toString(), 'kbazy');
assert.strictEqual(pt.read(5).toString(), 'bazyk');
assert.strictEqual(pt.read(5).toString(), 'uelku');
assert.strictEqual(pt.read(5).toString(), 'el');
}));
}
{
// Verify asymmetric transform (compress)
const pt = new Transform();
// Each output is the first char of 3 consecutive chunks,
// or whatever's left.
pt.state = '';
pt._transform = function(chunk, encoding, cb) {
if (!chunk)
chunk = '';
const s = chunk.toString();
setTimeout(() => {
this.state += s.charAt(0);
if (this.state.length === 3) {
pt.push(Buffer.from(this.state));
this.state = '';
}
cb();
}, 10);
};
pt._flush = function(cb) {
// Just output whatever we have.
pt.push(Buffer.from(this.state));
this.state = '';
cb();
};
pt.write(Buffer.from('aaaa'));
pt.write(Buffer.from('bbbb'));
pt.write(Buffer.from('cccc'));
pt.write(Buffer.from('dddd'));
pt.write(Buffer.from('eeee'));
pt.write(Buffer.from('aaaa'));
pt.write(Buffer.from('bbbb'));
pt.write(Buffer.from('cccc'));
pt.write(Buffer.from('dddd'));
pt.write(Buffer.from('eeee'));
pt.write(Buffer.from('aaaa'));
pt.write(Buffer.from('bbbb'));
pt.write(Buffer.from('cccc'));
pt.write(Buffer.from('dddd'));
pt.end();
// 'abcdeabcdeabcd'
pt.on('finish', common.mustCall(function() {
assert.strictEqual(pt.read(5).toString(), 'abcde');
assert.strictEqual(pt.read(5).toString(), 'abcde');
assert.strictEqual(pt.read(5).toString(), 'abcd');
}));
}
// This tests for a stall when data is written to a full stream
// that has empty transforms.
{
// Verify complex transform behavior
let count = 0;
let saved = null;
const pt = new Transform({ highWaterMark: 3 });
pt._transform = function(c, e, cb) {
if (count++ === 1)
saved = c;
else {
if (saved) {
pt.push(saved);
saved = null;
}
pt.push(c);
}
cb();
};
pt.once('readable', function() {
process.nextTick(function() {
pt.write(Buffer.from('d'));
pt.write(Buffer.from('ef'), common.mustCall(function() {
pt.end();
}));
assert.strictEqual(pt.read().toString(), 'abcdef');
assert.strictEqual(pt.read(), null);
});
});
pt.write(Buffer.from('abc'));
}
{
// Verify passthrough event emission
const pt = new PassThrough();
let emits = 0;
pt.on('readable', function() {
emits++;
});
pt.write(Buffer.from('foog'));
pt.write(Buffer.from('bark'));
assert.strictEqual(emits, 0);
assert.strictEqual(pt.read(5).toString(), 'foogb');
assert.strictEqual(String(pt.read(5)), 'null');
assert.strictEqual(emits, 0);
pt.write(Buffer.from('bazy'));
pt.write(Buffer.from('kuel'));
assert.strictEqual(emits, 0);
assert.strictEqual(pt.read(5).toString(), 'arkba');
assert.strictEqual(pt.read(5).toString(), 'zykue');
assert.strictEqual(pt.read(5), null);
pt.end();
assert.strictEqual(emits, 1);
assert.strictEqual(pt.read(5).toString(), 'l');
assert.strictEqual(pt.read(5), null);
assert.strictEqual(emits, 1);
}
{
// Verify passthrough event emission reordering
const pt = new PassThrough();
let emits = 0;
pt.on('readable', function() {
emits++;
});
pt.write(Buffer.from('foog'));
pt.write(Buffer.from('bark'));
assert.strictEqual(emits, 0);
assert.strictEqual(pt.read(5).toString(), 'foogb');
assert.strictEqual(pt.read(5), null);
pt.once('readable', common.mustCall(function() {
assert.strictEqual(pt.read(5).toString(), 'arkba');
assert.strictEqual(pt.read(5), null);
pt.once('readable', common.mustCall(function() {
assert.strictEqual(pt.read(5).toString(), 'zykue');
assert.strictEqual(pt.read(5), null);
pt.once('readable', common.mustCall(function() {
assert.strictEqual(pt.read(5).toString(), 'l');
assert.strictEqual(pt.read(5), null);
assert.strictEqual(emits, 3);
}));
pt.end();
}));
pt.write(Buffer.from('kuel'));
}));
pt.write(Buffer.from('bazy'));
}
{
// Verify passthrough facade
const pt = new PassThrough();
const datas = [];
pt.on('data', function(chunk) {
datas.push(chunk.toString());
});
pt.on('end', common.mustCall(function() {
assert.deepStrictEqual(datas, ['foog', 'bark', 'bazy', 'kuel']);
}));
pt.write(Buffer.from('foog'));
setTimeout(function() {
pt.write(Buffer.from('bark'));
setTimeout(function() {
pt.write(Buffer.from('bazy'));
setTimeout(function() {
pt.write(Buffer.from('kuel'));
setTimeout(function() {
pt.end();
}, 10);
}, 10);
}, 10);
}, 10);
}
{
// Verify object transform (JSON parse)
const jp = new Transform({ objectMode: true });
jp._transform = function(data, encoding, cb) {
try {
jp.push(JSON.parse(data));
cb();
} catch (er) {
cb(er);
}
};
// Anything except null/undefined is fine.
// those are "magic" in the stream API, because they signal EOF.
const objects = [
{ foo: 'bar' },
100,
'string',
{ nested: { things: [ { foo: 'bar' }, 100, 'string' ] } }
];
let ended = false;
jp.on('end', function() {
ended = true;
});
objects.forEach(function(obj) {
jp.write(JSON.stringify(obj));
const res = jp.read();
assert.deepStrictEqual(res, obj);
});
jp.end();
// Read one more time to get the 'end' event
jp.read();
process.nextTick(common.mustCall(function() {
assert.strictEqual(ended, true);
}));
}
{
// Verify object transform (JSON stringify)
const js = new Transform({ objectMode: true });
js._transform = function(data, encoding, cb) {
try {
js.push(JSON.stringify(data));
cb();
} catch (er) {
cb(er);
}
};
// Anything except null/undefined is fine.
// those are "magic" in the stream API, because they signal EOF.
const objects = [
{ foo: 'bar' },
100,
'string',
{ nested: { things: [ { foo: 'bar' }, 100, 'string' ] } }
];
let ended = false;
js.on('end', function() {
ended = true;
});
objects.forEach(function(obj) {
js.write(obj);
const res = js.read();
assert.strictEqual(res, JSON.stringify(obj));
});
js.end();
// Read one more time to get the 'end' event
js.read();
process.nextTick(common.mustCall(function() {
assert.strictEqual(ended, true);
}));
}