Added Jest and tests for EventBus

src/__tests__/event-bus-tests.ts

@@ -0,0 +1,123 @@
+import { EventBus } from '../event-bus'
+
+describe('EventBus', () => {
+  it('should refuse the registering of invalid ctx/event names', () => {
+    const eventBus = new EventBus()
+    expect(() => eventBus.on('@', 'event', () => {})).toThrowError(
+      'Invalid context/event name - Cannot contain @',
+    )
+    expect(() => eventBus.on('context', '@', () => {})).toThrowError(
+      'Invalid context/event name - Cannot contain @',
+    )
+  })
+
+  it('should emit different events to the same context', () => {
+    // Arrange
+    const bus = new EventBus()
+    const cb = jest.fn()
+    bus.on('context', 'event1', cb)
+    bus.on('context', 'event2', cb)
+
+    // Act
+    bus.emit('event1', 'PARAM_1')
+    bus.emit('event2', 'PARAM_2')
+
+    // Assert
+    expect(cb).toHaveBeenCalledTimes(2)
+    expect(cb).toHaveBeenNthCalledWith(1, 'PARAM_1')
+    expect(cb).toHaveBeenNthCalledWith(2, 'PARAM_2')
+  })
+
+  it('should emit the same events to different contexts', () => {
+    // Arrange
+    const bus = new EventBus()
+    const cb1 = jest.fn()
+    const cb2 = jest.fn()
+    bus.on('context1', 'event', cb1)
+    bus.on('context2', 'event', cb2)
+
+    // Act
+    bus.emit('event', 'PARAM_1')
+
+    // Assert
+    expect(cb1).toHaveBeenCalledTimes(1)
+    expect(cb1).toHaveBeenNthCalledWith(1, 'PARAM_1')
+    expect(cb2).toHaveBeenCalledTimes(1)
+    expect(cb2).toHaveBeenNthCalledWith(1, 'PARAM_1')
+  })
+
+  it('should forward multiple arguments', () => {
+    // Arrange
+    const bus = new EventBus()
+    const cb = jest.fn()
+    bus.on('context', 'event', cb)
+
+    // Act
+    bus.emit('event', 'foo', 'bar')
+
+    // Assert
+    expect(cb).toHaveBeenCalledWith('foo', 'bar')
+  })
+
+  it('should not emit events for disabled contexts', () => {
+    // Arrange
+    const bus = new EventBus()
+    const cb = jest.fn()
+    bus.on('context', 'event', cb)
+    bus.disable('context')
+
+    // Act
+    bus.emit('event', 'foo', 'bar')
+
+    // Assert
+    expect(cb).not.toHaveBeenCalled()
+  })
+
+  it('should emit events for enabled contexts', () => {
+    // Arrange
+    const bus = new EventBus()
+    const cb = jest.fn()
+    bus.on('context', 'event', cb)
+    bus.disable('context')
+    bus.enable('context')
+
+    // Act
+    bus.emit('event', 'foo', 'bar')
+
+    // Assert
+    expect(cb).toHaveBeenCalledWith('foo', 'bar')
+  })
+
+  it('should unregister contexts', () => {
+    // Arrange
+    const bus = new EventBus()
+    const cb = jest.fn()
+    bus.on('context1', 'event', cb)
+    bus.on('context2', 'event', cb)
+    bus.off('context1')
+
+    // Act
+    bus.emit('event', 'foo', 'bar')
+
+    // Assert
+    expect(cb).toHaveBeenCalledTimes(1)
+  })
+
+  it('should unregister single events', () => {
+    // Arrange
+    const bus = new EventBus()
+    const cb1 = jest.fn()
+    const cb2 = jest.fn()
+    bus.on('context', 'event1', cb1)
+    bus.on('context', 'event2', cb2)
+    bus.off('context', 'event2')
+
+    // Act
+    bus.emit('event1')
+    bus.emit('event2')
+
+    // Assert
+    expect(cb1).toHaveBeenCalled()
+    expect(cb2).not.toHaveBeenCalled()
+  })
+})