add hw2

node_modules/events/tests/modify-in-emit.js

@@ -0,0 +1,90 @@
+// 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.
+
+require('./common');
+var assert = require('assert');
+var events = require('../');
+
+var callbacks_called = [];
+
+var e = new events.EventEmitter();
+
+function callback1() {
+  callbacks_called.push('callback1');
+  e.on('foo', callback2);
+  e.on('foo', callback3);
+  e.removeListener('foo', callback1);
+}
+
+function callback2() {
+  callbacks_called.push('callback2');
+  e.removeListener('foo', callback2);
+}
+
+function callback3() {
+  callbacks_called.push('callback3');
+  e.removeListener('foo', callback3);
+}
+
+e.on('foo', callback1);
+assert.strictEqual(e.listeners('foo').length, 1);
+
+e.emit('foo');
+assert.strictEqual(e.listeners('foo').length, 2);
+assert.ok(Array.isArray(callbacks_called));
+assert.strictEqual(callbacks_called.length, 1);
+assert.strictEqual(callbacks_called[0], 'callback1');
+
+e.emit('foo');
+assert.strictEqual(e.listeners('foo').length, 0);
+assert.ok(Array.isArray(callbacks_called));
+assert.strictEqual(callbacks_called.length, 3);
+assert.strictEqual(callbacks_called[0], 'callback1');
+assert.strictEqual(callbacks_called[1], 'callback2');
+assert.strictEqual(callbacks_called[2], 'callback3');
+
+e.emit('foo');
+assert.strictEqual(e.listeners('foo').length, 0);
+assert.ok(Array.isArray(callbacks_called));
+assert.strictEqual(callbacks_called.length, 3);
+assert.strictEqual(callbacks_called[0], 'callback1');
+assert.strictEqual(callbacks_called[1], 'callback2');
+assert.strictEqual(callbacks_called[2], 'callback3');
+
+e.on('foo', callback1);
+e.on('foo', callback2);
+assert.strictEqual(e.listeners('foo').length, 2);
+e.removeAllListeners('foo');
+assert.strictEqual(e.listeners('foo').length, 0);
+
+// Verify that removing callbacks while in emit allows emits to propagate to
+// all listeners
+callbacks_called = [];
+
+e.on('foo', callback2);
+e.on('foo', callback3);
+assert.strictEqual(2, e.listeners('foo').length);
+e.emit('foo');
+assert.ok(Array.isArray(callbacks_called));
+assert.strictEqual(callbacks_called.length, 2);
+assert.strictEqual(callbacks_called[0], 'callback2');
+assert.strictEqual(callbacks_called[1], 'callback3');
+assert.strictEqual(0, e.listeners('foo').length);