event-emitters
Version:
72 lines • 2.96 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
var _1 = require(".");
describe('QueueingEventEmitter', function () {
var createEventEmitter = function () { return new _1.QueueingEventEmitter(); };
var emitter = createEventEmitter();
beforeEach(function () {
emitter = createEventEmitter();
});
it('queues messages when there are no subscribers and emits them to first subscriber', function () {
var subscriber = jest.fn();
emitter.emit('one');
emitter.emit('two');
emitter.subscribe(subscriber);
expect(subscriber.mock.calls).toEqual([['one'], ['two']]);
});
it('stops queueing messages when there is a subscriber', function () {
var subscriber = jest.fn();
emitter.emit('one');
emitter.emit('two');
emitter.subscribe(subscriber);
expect(subscriber.mock.calls).toEqual([['one'], ['two']]);
emitter.emit('three');
expect(subscriber.mock.calls).toEqual([['one'], ['two'], ['three']]);
});
it('resumes queueing message when it loses all subscribers', function () {
var subscriber1 = jest.fn();
var subscriber2 = jest.fn();
emitter.emit('one');
emitter.emit('two');
emitter.subscribe(subscriber1);
emitter.subscribe(subscriber2);
expect(subscriber1.mock.calls).toEqual([['one'], ['two']]);
expect(subscriber2).toHaveBeenCalledTimes(0);
emitter.emit('three');
expect(subscriber1.mock.calls).toEqual([['one'], ['two'], ['three']]);
expect(subscriber2.mock.calls).toEqual([['three']]);
emitter.unsubscribe(subscriber1);
emitter.emit('four');
expect(subscriber1).toHaveBeenCalledTimes(3);
expect(subscriber2.mock.calls).toEqual([['three'], ['four']]);
emitter.unsubscribe(subscriber2);
emitter.emit('five');
emitter.emit('six');
var subscriber3 = jest.fn();
emitter.subscribe(subscriber3);
expect(subscriber3.mock.calls).toEqual([['five'], ['six']]);
emitter.emit('seven');
expect(subscriber3.mock.calls).toEqual([['five'], ['six'], ['seven']]);
});
it('re-throws the final error when the subscriber throws during queue drain', function () {
var subscriber1 = jest
.fn()
.mockImplementationOnce(function () {
throw new Error('1');
})
.mockImplementationOnce(function () {
throw new Error('2');
});
emitter.emit('one');
emitter.emit('two');
emitter.emit('three');
expect(function () {
emitter.subscribe(subscriber1);
}).toThrow('2');
// make sure the queue is drained
var subscriber2 = jest.fn();
emitter.subscribe(subscriber2);
expect(subscriber2).toHaveBeenCalledTimes(0);
});
});
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