From d59f3944ef7d1a848481b72ca8bffaf82e758f64 Mon Sep 17 00:00:00 2001
From: Peter Hooper <diversemix@gmail.com>
Date: Thu, 2 Jan 2020 16:41:39 +0000
Subject: [PATCH] Add more tests and figure out how the bus will work
---
src/event-bus/event-bus.test.ts | 18 ++-
src/event-bus/event-factory.test.ts | 62 --------
src/event-bus/event-factory.ts | 22 ---
src/event-bus/index.ts | 2 +-
src/event-bus/types.test.ts | 46 +++---
src/event-bus/types.ts | 19 +--
src/mock-event-bus/index.test.ts | 189 +++++++++++++++----------
src/mock-event-bus/index.ts | 26 ++--
src/rabbit-event-bus/amqp-connector.ts | 24 ++--
src/rabbit-event-bus/index.ts | 14 +-
src/rabbit-event-bus/internal-queue.ts | 4 +-
src/rabbit-event-bus/types.ts | 4 +-
12 files changed, 183 insertions(+), 247 deletions(-)
delete mode 100644 src/event-bus/event-factory.test.ts
delete mode 100644 src/event-bus/event-factory.ts
diff --git a/src/event-bus/event-bus.test.ts b/src/event-bus/event-bus.test.ts
index 4f4a8d1..a8582b9 100644
--- a/src/event-bus/event-bus.test.ts
+++ b/src/event-bus/event-bus.test.ts
@@ -1,16 +1,26 @@
import { EventBus } from './event-bus';
describe('Event Bus class', () => {
- it('EventBus is abstract', () => {
- const create = (T): EventBus => new T(['test'], 'test');
+ const create = (T): EventBus => new T(['test'], 'test');
+ it('is abstract', () => {
+ const x = create(EventBus);
+ expect(() => x.destroy()).toThrow('x.destroy is not a function');
+ });
+ it('initialises members', () => {
const x = create(EventBus);
expect(x.eventsToHandle).toStrictEqual(['test']);
expect(x.serviceName).toStrictEqual('test');
- expect(() => x.destroy()).toThrow('x.destroy is not a function');
});
- it('EventBus can be extended', () => {
+ it('has correct members', () => {
+ const keys = Object.keys(create(EventBus));
+ expect(keys).toHaveLength(2);
+ expect(keys).toContain('eventsToHandle');
+ expect(keys).toContain('serviceName');
+ });
+
+ it('can be extended', () => {
class EB extends EventBus {
called = false;
destroy(): Promise<void> {
diff --git a/src/event-bus/event-factory.test.ts b/src/event-bus/event-factory.test.ts
deleted file mode 100644
index 27e1219..0000000
--- a/src/event-bus/event-factory.test.ts
+++ /dev/null
@@ -1,62 +0,0 @@
-import { eventFactory, eventAbstractFactory } from './event-factory';
-import { Event, Payload } from './types';
-
-describe('Event Creation', () => {
- describe('eventFactory', () => {
- it('creates an Event', () => {
- const payload = new Payload();
- const event = eventFactory('type', payload);
- expect(event.id).toHaveLength(36);
- expect(event.eventType).toBe('type');
- expect(event.created instanceof Date).toBe(true);
- expect(event.payload).toBe(payload);
- });
-
- it('fails to create an Event without a payload of type Payload', () => {
- expect(() => eventFactory('type', {})).toThrow('argument payload is not of type Payload!');
- });
- });
-
- describe('eventAbstractFactory', () => {
- class Party extends Payload {
- beer: boolean;
- address: string;
- }
- class EventParty extends Event {}
-
- class GardenParty extends Payload {
- wine: boolean;
- }
-
- it('creates an Event of correct type', () => {
- const payload = new Party();
- payload.beer = true;
- payload.address = 'my place';
-
- const event: EventParty = eventAbstractFactory('party', Party, payload);
-
- expect(event.id).toHaveLength(36);
- expect(event.eventType).toBe('party');
- expect(event.created instanceof Date).toBe(true);
- expect(event.payload).toHaveProperty('beer');
- expect(event.payload['beer']).toBe(true);
- expect(event.payload).toHaveProperty('address');
- expect(event.payload['address']).toBe('my place');
- });
-
- it('rejects arbitrary payload type', () => {
- const payload = { address: 'my place' };
- const create = (p: object): EventParty => eventAbstractFactory('party', Party, p);
-
- expect(() => create(payload)).toThrow('expected payload of type Party got Object');
- });
-
- it('rejects incorrect payload type', () => {
- const payload = new GardenParty();
- payload.wine = true;
- const create = (p: GardenParty): EventParty => eventAbstractFactory('party', Party, p);
-
- expect(() => create(payload)).toThrow('expected payload of type Party got GardenParty');
- });
- });
-});
diff --git a/src/event-bus/event-factory.ts b/src/event-bus/event-factory.ts
deleted file mode 100644
index efe410c..0000000
--- a/src/event-bus/event-factory.ts
+++ /dev/null
@@ -1,22 +0,0 @@
-import { Event, Payload } from './types';
-import uuid = require('uuid');
-
-export const eventFactory = (eventType: string, payload: Payload): Event => {
- if (!(payload instanceof Payload)) {
- throw new TypeError('argument payload is not of type Payload!');
- }
- return {
- eventType,
- id: uuid.v4(),
- created: new Date(),
- payload,
- };
-};
-
-export const eventAbstractFactory = (typeName: string, payloadClass, p: object): Event => {
- if (payloadClass.name !== p.constructor.name) {
- throw new TypeError(`expected payload of type ${payloadClass.name} got ${p.constructor.name}`);
- }
- const event = eventFactory(typeName, p);
- return event;
-};
diff --git a/src/event-bus/index.ts b/src/event-bus/index.ts
index 999b47e..041c657 100644
--- a/src/event-bus/index.ts
+++ b/src/event-bus/index.ts
@@ -1,3 +1,3 @@
export * from './types';
+export * from './event';
export * from './event-bus';
-export * from './event-factory';
diff --git a/src/event-bus/types.test.ts b/src/event-bus/types.test.ts
index e507e82..d906159 100644
--- a/src/event-bus/types.test.ts
+++ b/src/event-bus/types.test.ts
@@ -1,4 +1,5 @@
-import { EventType, Event, EventPublisher, EventSubscriber, EventConfig } from './types';
+import { EventType, EventPublisher, EventSubscriber, EventConfig } from './types';
+import { Event } from './event';
function createValidationFunction<T>(properties: Record<keyof T, boolean>): Function {
return function<TActual extends T>(value: TActual): T {
@@ -26,42 +27,23 @@ function createValidationFunction<T>(properties: Record<keyof T, boolean>): Func
};
}
-describe('Event Bus Types', () => {
- it('type EventType is string', () => {
+describe('EventType', () => {
+ it('is string', () => {
const et: EventType = 'this is a string';
expect(typeof et).toBe('string');
});
+});
- it('interface Event contains expected members', () => {
- const expectedEventProperties = {
- eventType: true,
- id: true,
- created: true,
- payload: true,
- version: false,
- context: false,
- };
-
- class ExpectedToBeAnEvent {
- id = '234';
- created: Date = new Date();
- payload: {} = {};
- eventType = 'type';
- }
- const isValidEvent = createValidationFunction<Event<{}>>(expectedEventProperties);
- const ee = new ExpectedToBeAnEvent();
- expect(() => isValidEvent(ee)).not.toThrow();
- expect(() => ee as Event<{}>).not.toThrow();
- });
-
- it('interface EventPublisher contains expected members', () => {
+describe('EventPublisher', () => {
+ it('contains contains only publish', () => {
const expectedEventPublisherProperties = {
publish: true,
};
class ExpectedToBeAnEventPublisher {
- publish<T extends object>(event: Event<T>): Promise<boolean> {
- return Promise.resolve(event !== null);
+ publish(event: Event): Promise<void> {
+ expect(event).toBeTruthy();
+ return Promise.resolve();
}
}
const isValidEventPublisher = createValidationFunction<EventPublisher>(expectedEventPublisherProperties);
@@ -69,14 +51,16 @@ describe('Event Bus Types', () => {
expect(() => isValidEventPublisher(ep)).not.toThrow();
expect(() => ep as EventPublisher).not.toThrow();
});
+});
+describe('EventSubscription', () => {
it('interface EventSubscriber contains expected members', () => {
const expectedEventSubscriberProperties = {
subscribe: true,
};
class ExpectedToBeAnEventSubscriber {
- subscribe<T extends object>(eventType: string, handler: (event: Event<T>) => Promise<boolean>): void {
+ subscribe(eventType: string, handler: (event: Event) => Promise<boolean>): void {
Promise.resolve(eventType !== '' && handler !== null);
}
}
@@ -85,8 +69,10 @@ describe('Event Bus Types', () => {
expect(() => isValidEventSubscriber(es)).not.toThrow();
expect(() => es as EventSubscriber).not.toThrow();
});
+});
- it('interface EventConfig contains expected members', () => {
+describe('EventConfig', () => {
+ it('contains only url', () => {
const expectedEventConfigProperties = {
url: true,
};
diff --git a/src/event-bus/types.ts b/src/event-bus/types.ts
index 10ace28..a07782b 100644
--- a/src/event-bus/types.ts
+++ b/src/event-bus/types.ts
@@ -1,27 +1,14 @@
// Abstract Message Queue - types and interfaces
+import { Event } from './event';
export type EventType = string;
-export class Payload {}
-
-export class Event {
- readonly eventType: EventType;
- readonly id: string; // Generated when the event is emitted
- readonly created: Date;
- // version: has been removed - so we can remain weakly typed
- // context: has also been removed - if you need information about the origin
- // source of the event then put it in the payload.
-
- constructor(readonly payload: Payload) {}
-}
-
export interface EventPublisher {
- // Promise<boolean> should this become void | exception? we only need to know if something went wrong
- publish(event: Event): Promise<boolean>;
+ publish(event: Event): Promise<void>;
}
export interface EventSubscriber {
- // handler: returns whether or not we should ack the message
+ // handler: returns whether or not the EventBus implementation should ack the message
subscribe(eventType: string, handler: (event: Event) => Promise<boolean>): void;
}
diff --git a/src/mock-event-bus/index.test.ts b/src/mock-event-bus/index.test.ts
index edded42..1efe500 100644
--- a/src/mock-event-bus/index.test.ts
+++ b/src/mock-event-bus/index.test.ts
@@ -1,88 +1,127 @@
import { MockEventBus } from './index';
-import { Event, Payload } from '../event-bus/types';
-import { eventFactory } from '../event-bus/event-factory';
-
-describe('mock message queue', () => {
- // describe('object lifetime', () => {
- // it('can do the full flow', async () => {
- // const x = 2;
- // });
- // });
-
- describe('you can publish and subscribe', () => {
- it('can do the full flow', async () => {
- const eventType = 'libero:mock:test';
-
- const mockHandler = jest.fn(async () => true);
- const mockEventBus = new MockEventBus([eventType], 'message-bus-test');
-
- mockEventBus.subscribe(eventType, mockHandler);
- const payload = new Payload();
-
- const event = eventFactory(eventType, payload);
-
- mockEventBus.publish(event);
-
- expect(mockHandler).toBeCalled();
- expect(mockHandler.mock.calls).toEqual([[event]]);
- });
-
- it('can discriminate based on event type', async () => {
- const eventType1 = 'libero:mock:test1';
- const eventType2 = 'libero:mock:test2';
-
- const event1: Event = {
- eventType: eventType1,
- id: 'some-testing-event1-id',
- created: new Date(),
- payload: { x: 10, y: 20 },
- };
-
- const event2: Event = {
- eventType: eventType2,
- id: 'some-testing-event2-id',
+import { Event, EventType } from '../event-bus';
+
+class TestEvent extends Event {
+ static eventName: EventType = 'libero:mock:test';
+ constructor(payload: object) {
+ super(TestEvent.eventName, payload);
+ }
+}
+const mockHandler = jest.fn(
+ (): Promise<boolean> => {
+ return Promise.resolve(true);
+ },
+);
+
+describe('MockEventBus', () => {
+ it('can publish to many event types without handlers', () => {
+ const mockEventBus = new MockEventBus(['some-event'], 'message-bus-test');
+ [...Array(100).keys()].map(key => {
+ const e: Event = {
+ eventType: 'event' + key.toString(),
+ id: '0',
created: new Date(),
- payload: { a: 10, b: 20 },
+ payload: {},
};
+ mockEventBus.publish(e);
+ });
+ });
- let handler1 = 0;
- let handler2 = 0;
- let receivedEvent1: object = {};
- let receivedEvent2: object = {};
-
- const mockHandler1 = async (event: Event): Promise<boolean> => {
- handler1 += 1;
- receivedEvent1 = event;
-
- return Promise.resolve(true);
- };
+ it('publish throws if no handler', async () => {
+ const mockEventBus = new MockEventBus([TestEvent.eventName], 'message-bus-test');
+ const testEvent = new TestEvent({ x: 'test' });
+ expect(mockEventBus.publish(testEvent)).rejects.toStrictEqual(
+ new Error('handler for libero:mock:test is undefined or not a function'),
+ );
+ });
- const mockHandler2 = async (event: Event): Promise<boolean> => {
- handler2 += 1;
- receivedEvent2 = event;
- return Promise.resolve(true);
- };
+ it('subscribe throws if no service name', async () => {
+ const mockEventBus = new MockEventBus([TestEvent.eventName], '');
+ const testEvent = new TestEvent({ x: 'test' });
+ expect(mockEventBus.subscribe(testEvent.eventType, mockHandler)).rejects.toStrictEqual(
+ new Error('Service name not set!'),
+ );
+ });
- const mockEventBus = new MockEventBus([eventType1, eventType2], 'message-bus-test');
+ it('subscribe throws if no event name', async () => {
+ const mockEventBus = new MockEventBus([TestEvent.eventName], 'service');
+ expect(mockEventBus.subscribe('', mockHandler)).rejects.toStrictEqual(new Error('EventType name not set!'));
+ });
- mockEventBus.subscribe(eventType1, mockHandler1);
- mockEventBus.subscribe(eventType2, mockHandler2);
+ it('subscribe throws if handler set twice', async () => {
+ const mockEventBus = new MockEventBus([TestEvent.eventName], 'service');
+ expect(mockEventBus.subscribe('test', mockHandler)).resolves.not.toThrow();
+ expect(mockEventBus.subscribe('test', mockHandler)).rejects.toStrictEqual(
+ new Error(`Handler already set for 'test' set!`),
+ );
+ });
- mockEventBus.publish(event2);
+ it('can publish and subscribe to the same EventType', async () => {
+ const mockEventBus = new MockEventBus([TestEvent.eventName], 'message-bus-test');
- expect(handler1).toBe(0);
- expect(handler2).toBe(1);
- expect(receivedEvent1).toEqual({});
- expect(receivedEvent2).toEqual(event2);
+ await mockEventBus.subscribe(TestEvent.eventName, mockHandler);
+ const testEvent = new TestEvent({ x: 'test' });
+ await mockEventBus.publish(testEvent);
- receivedEvent1 = {};
- receivedEvent2 = {};
- mockEventBus.publish(event1);
+ expect(mockHandler).toBeCalled();
+ expect(mockHandler.mock.calls).toEqual([[testEvent]]);
+ });
- expect(handler1).toBe(1);
- expect(handler2).toBe(1);
- expect(receivedEvent1).toEqual(event1);
- expect(receivedEvent2).toEqual({});
- });
+ it('can discriminate based on event type', async () => {
+ const eventType1 = 'libero:mock:test1';
+ const eventType2 = 'libero:mock:test2';
+
+ const event1: Event = {
+ eventType: eventType1,
+ id: 'some-testing-event1-id',
+ created: new Date(),
+ payload: { x: 10, y: 20 },
+ };
+
+ const event2: Event = {
+ eventType: eventType2,
+ id: 'some-testing-event2-id',
+ created: new Date(),
+ payload: { a: 10, b: 20 },
+ };
+
+ let handler1 = 0;
+ let handler2 = 0;
+ let receivedEvent1: object = {};
+ let receivedEvent2: object = {};
+
+ const mockHandler1 = async (event: Event): Promise<boolean> => {
+ handler1 += 1;
+ receivedEvent1 = event;
+
+ return Promise.resolve(true);
+ };
+
+ const mockHandler2 = async (event: Event): Promise<boolean> => {
+ handler2 += 1;
+ receivedEvent2 = event;
+ return Promise.resolve(true);
+ };
+
+ const mockEventBus = new MockEventBus([eventType1, eventType2], 'message-bus-test');
+
+ mockEventBus.subscribe(eventType1, mockHandler1);
+ mockEventBus.subscribe(eventType2, mockHandler2);
+
+ mockEventBus.publish(event2);
+
+ expect(handler1).toBe(0);
+ expect(handler2).toBe(1);
+ expect(receivedEvent1).toEqual({});
+ expect(receivedEvent2).toEqual(event2);
+
+ receivedEvent1 = {};
+ receivedEvent2 = {};
+ mockEventBus.publish(event1);
+
+ expect(handler1).toBe(1);
+ expect(handler2).toBe(1);
+ expect(receivedEvent1).toEqual(event1);
+ expect(receivedEvent2).toEqual({});
});
});
diff --git a/src/mock-event-bus/index.ts b/src/mock-event-bus/index.ts
index 86d6b48..8bb15d4 100644
--- a/src/mock-event-bus/index.ts
+++ b/src/mock-event-bus/index.ts
@@ -10,21 +10,31 @@ export type AnyHandler = (ev: AnyEvent) => Promise<boolean>;
export class MockEventBus extends EventBus implements EventPublisher, EventSubscriber {
private queues: Map<string, AnyHandler> = new Map();
- public async publish(event: Event): Promise<boolean> {
+ public async publish(event: Event): Promise<void> {
+ if (!this.eventsToHandle.includes(event.eventType)) {
+ return;
+ }
const fn = this.queues.get(`${event.eventType}`);
- if (fn) {
- if (this.eventsToHandle.includes(event.eventType)) {
- return fn(event);
- }
+
+ if (fn !== undefined && typeof fn === 'function') {
+ fn(event);
+ } else {
+ throw new Error(`handler for ${event.eventType} is undefined or not a function`);
}
- return Promise.resolve(false);
}
public async subscribe(eventType: string, handler: (event: Event) => Promise<boolean>): Promise<void> {
if (!this.serviceName) {
- Promise.reject(`Service name not set!`);
+ throw new Error(`Service name not set!`);
+ }
+ if (!eventType) {
+ throw new Error(`EventType name not set!`);
+ }
+ const key = `${eventType}`;
+ if (this.queues.has(key)) {
+ throw new Error(`Handler already set for '${eventType}' set!`);
}
- this.queues.set(`${eventType}`, handler);
+ this.queues.set(key, handler);
}
destroy(): Promise<void> {
diff --git a/src/rabbit-event-bus/amqp-connector.ts b/src/rabbit-event-bus/amqp-connector.ts
index 84f648d..53d0f4a 100644
--- a/src/rabbit-event-bus/amqp-connector.ts
+++ b/src/rabbit-event-bus/amqp-connector.ts
@@ -20,7 +20,7 @@ export default class AMQPConnector {
url: string,
[sender]: Channel<StateChange>,
eventDefs: string[],
- subscriptions: Array<Subscription<unknown & object>>,
+ subscriptions: Array<Subscription>,
serviceName: string,
) {
this.externalConnector = { send: sender };
@@ -47,10 +47,7 @@ export default class AMQPConnector {
}
}
- public async subscribe<P extends object>(
- eventType: EventType,
- handler: (ev: Event<P>) => Promise<boolean>,
- ): Promise<void> {
+ public async subscribe(eventType: EventType, handler: (ev: Event) => Promise<boolean>): Promise<void> {
// For the event identifier:
// - Declare a subscriber queue
// - bind that queue to event exchange
@@ -71,7 +68,7 @@ export default class AMQPConnector {
this.subscriptions.push(eventType);
await rabbitChannel.consume(qName, async (msg: Message) => {
- return this.decoratedHandler<P>(rabbitChannel, handler, msg);
+ return this.decoratedHandler(rabbitChannel, handler, msg);
});
})
.catch(() => {
@@ -84,7 +81,7 @@ export default class AMQPConnector {
}
}
- public async publish<P extends object>(event: Event<P>): Promise<boolean> {
+ public async publish(event: Event): Promise<boolean> {
// publish the message
const whereTo = EventUtils.makeEventExchangeName(event.eventType);
return Option.of(this.connection)
@@ -123,13 +120,13 @@ export default class AMQPConnector {
}
}
- private decoratedHandler<P extends object>(
+ private decoratedHandler(
rabbitChannel: amqplib.Channel,
- handler: (ev: Event<P>) => Promise<boolean>,
+ handler: (ev: Event) => Promise<boolean>,
msg: Message,
): void {
try {
- const message: EventBusMessage<Event<P>> = JSON.parse(msg.content.toString());
+ const message: EventBusMessage<Event> = JSON.parse(msg.content.toString());
handler(message.event).then(isOk => {
if (isOk) {
@@ -147,12 +144,7 @@ export default class AMQPConnector {
}
}
- private async setupExchanges(
- eventDefs: string[],
- subscriptions: Array<Subscription<unknown & object>>,
- ): Promise<void> {
- // Setup the exchanges
-
+ private async setupExchanges(eventDefs: string[], subscriptions: Array<Subscription>): Promise<void> {
const rabbitChannel = await this.connection.createChannel();
this.subscriptions = [];
diff --git a/src/rabbit-event-bus/index.ts b/src/rabbit-event-bus/index.ts
index d375780..e224e32 100644
--- a/src/rabbit-event-bus/index.ts
+++ b/src/rabbit-event-bus/index.ts
@@ -24,7 +24,7 @@ export default class RabbitEventBus extends EventBus implements EventPublisher,
private connection: ConnectionObserver;
private url = '';
private queue: InternalMessageQueue;
- private _subscriptions: Array<Subscription<unknown & object>> = [];
+ private _subscriptions: Array<Subscription> = [];
public constructor(
connectionOpts: RabbitEventBusConnectionOptions,
@@ -42,7 +42,7 @@ export default class RabbitEventBus extends EventBus implements EventPublisher,
return this._connector;
}
- public get subscriptions(): Array<Subscription<unknown & object>> {
+ public get subscriptions(): Array<Subscription> {
return this._subscriptions;
}
@@ -79,17 +79,16 @@ export default class RabbitEventBus extends EventBus implements EventPublisher,
// This method will not resolve until the event has been successfully published so that
// the user never has to know about the internal queue
- public publish<P extends object>(msg: Event<P>): Promise<boolean> {
+ public publish(msg: Event): Promise<void> {
return new Promise(async (resolve, reject) => {
if (this.connection.isConnected) {
- // Should we queue messages that fail?
const published: boolean = await this.connector.get().publish(msg);
if (!published) {
const qEvent: QueuedEvent = { event: msg, resolve, reject };
this.queue.push(qEvent);
} else {
- resolve(published);
+ resolve();
}
} else {
const qEvent: QueuedEvent = { event: msg, resolve, reject };
@@ -98,10 +97,7 @@ export default class RabbitEventBus extends EventBus implements EventPublisher,
});
}
- public async subscribe<P extends object>(
- eventType: string,
- handler: (event: Event<P>) => Promise<boolean>,
- ): Promise<number> {
+ public async subscribe(eventType: string, handler: (event: Event) => Promise<boolean>): Promise<number> {
this.connector.map(connector => {
connector.subscribe(eventType, handler);
});
diff --git a/src/rabbit-event-bus/internal-queue.ts b/src/rabbit-event-bus/internal-queue.ts
index 8c4f521..3be0ef1 100644
--- a/src/rabbit-event-bus/internal-queue.ts
+++ b/src/rabbit-event-bus/internal-queue.ts
@@ -2,8 +2,8 @@ import { Event, EventPublisher } from '../event-bus';
import { Option } from 'funfix';
export interface QueuedEvent {
- event: Event<unknown & object>;
- resolve: (arg0: boolean) => void;
+ event: Event;
+ resolve: (arg0: void) => void;
reject: (arg0: boolean) => void;
}
diff --git a/src/rabbit-event-bus/types.ts b/src/rabbit-event-bus/types.ts
index ddffe7d..6cb9210 100644
--- a/src/rabbit-event-bus/types.ts
+++ b/src/rabbit-event-bus/types.ts
@@ -16,7 +16,7 @@ export interface Message<T> {
};
}
-export interface Subscription<P extends object> {
+export interface Subscription {
eventType: string;
- handler: (ev: Event<P>) => Promise<boolean>;
+ handler: (ev: Event) => Promise<boolean>;
}
--
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