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'use strict';
const common = require('../common');
const stream = require('stream');
const assert = require('assert');
// This is very similar to test-stream-pipe-cleanup-pause.js.
const reader = new stream.Readable();
const writer1 = new stream.Writable();
const writer2 = new stream.Writable();
const writer3 = new stream.Writable();
// 560000 is chosen here because it is larger than the (default) highWaterMark
// and will cause `.write()` to return false
// See: https://github.com/nodejs/node/issues/5820
const buffer = Buffer.allocUnsafe(560000);
reader._read = () => {};
writer1._write = common.mustCall(function(chunk, encoding, cb) {
this.emit('chunk-received');
cb();
}, 1);
writer1.once('chunk-received', () => {
assert.strictEqual(
reader._readableState.awaitDrain,
0,
'awaitDrain initial value should be 0, actual is ' +
reader._readableState.awaitDrain
);
setImmediate(() => {
// This one should *not* get through to writer1 because writer2 is not
// "done" processing.
reader.push(buffer);
});
});
// A "slow" consumer:
writer2._write = common.mustCall((chunk, encoding, cb) => {
assert.strictEqual(
reader._readableState.awaitDrain,
1,
'awaitDrain should be 1 after first push, actual is ' +
reader._readableState.awaitDrain
);
// Not calling cb here to "simulate" slow stream.
// This should be called exactly once, since the first .write() call
// will return false.
}, 1);
writer3._write = common.mustCall((chunk, encoding, cb) => {
assert.strictEqual(
reader._readableState.awaitDrain,
2,
'awaitDrain should be 2 after second push, actual is ' +
reader._readableState.awaitDrain
);
// Not calling cb here to "simulate" slow stream.
// This should be called exactly once, since the first .write() call
// will return false.
}, 1);
reader.pipe(writer1);
reader.pipe(writer2);
reader.pipe(writer3);
reader.push(buffer);
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