mirror of https://gitee.com/openkylin/nodejs.git
43 lines
1.1 KiB
JavaScript
43 lines
1.1 KiB
JavaScript
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'use strict';
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const common = require('../common');
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const EventEmitter = require('events');
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const assert = require('assert');
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const myEE = new EventEmitter();
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let m = 0;
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// This one comes last.
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myEE.on('foo', common.mustCall(() => assert.strictEqual(m, 2)));
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// This one comes second.
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myEE.prependListener('foo', common.mustCall(() => assert.strictEqual(m++, 1)));
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// This one comes first.
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myEE.prependOnceListener('foo',
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common.mustCall(() => assert.strictEqual(m++, 0)));
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myEE.emit('foo');
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// Test fallback if prependListener is undefined.
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const stream = require('stream');
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delete EventEmitter.prototype.prependListener;
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function Writable() {
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this.writable = true;
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stream.Stream.call(this);
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}
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Object.setPrototypeOf(Writable.prototype, stream.Stream.prototype);
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Object.setPrototypeOf(Writable, stream.Stream);
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function Readable() {
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this.readable = true;
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stream.Stream.call(this);
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}
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Object.setPrototypeOf(Readable.prototype, stream.Stream.prototype);
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Object.setPrototypeOf(Readable, stream.Stream);
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const w = new Writable();
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const r = new Readable();
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r.pipe(w);
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