Extended Emmett appending events and getting state exercises with PostgreSQL and EventStoreDB

Author: oskardudycz

workshops/introduction_to_event_sourcing/src/04_appending_events_emmett/eventstoredb/appendingEvents.exercise.test.ts

@@ -1,4 +1,7 @@
-import { getEventStoreDBTestClient } from '#core/testing/eventStoreDB';
+import {
+  getEventStoreDBTestClient,
+  releaseEventStoreDBContainer,
+} from '#core/testing/eventStoreDB';
 import { type Event } from '@event-driven-io/emmett';
 import {
   type EventStoreDBEventStore,
@@ -81,6 +84,8 @@ describe('Appending events', () => {
     eventStore = getEventStoreDBEventStore(client);
   });
 
+  afterAll(() => releaseEventStoreDBContainer());
+
   it('should append events to EventStoreDB', async () => {
     const shoppingCartId = uuid();
     const clientId = uuid();

workshops/introduction_to_event_sourcing/src/04_appending_events_emmett/postgresql/appendingEvents.exercise.test.ts

@@ -2,7 +2,7 @@ import { type Event } from '@event-driven-io/emmett';
 import {
   getPostgreSQLEventStore,
   type PostgresEventStore,
-} from '@event-driven-io/emmett-postgresql/.';
+} from '@event-driven-io/emmett-postgresql';
 import { v4 as uuid } from 'uuid';
 import {
   getPostgreSQLConnectionString,

workshops/introduction_to_event_sourcing/src/06_getting_state_from_events_emmett/eventstoredb/immutable/gettingStateFromEvents.exercise.test.ts

@@ -0,0 +1,205 @@
+import {
+  getEventStoreDBTestClient,
+  releaseEventStoreDBContainer,
+} from '#core/testing/eventStoreDB';
+import { type Event } from '@event-driven-io/emmett';
+import {
+  type EventStoreDBEventStore,
+  getEventStoreDBEventStore,
+} from '@event-driven-io/emmett-esdb';
+import { v4 as uuid } from 'uuid';
+
+export interface ProductItem {
+  productId: string;
+  quantity: number;
+}
+
+export type PricedProductItem = ProductItem & {
+  unitPrice: number;
+};
+
+export type ShoppingCartOpened = Event<
+  'ShoppingCartOpened',
+  {
+    shoppingCartId: string;
+    clientId: string;
+    openedAt: Date;
+  }
+>;
+
+export type ProductItemAddedToShoppingCart = Event<
+  'ProductItemAddedToShoppingCart',
+  {
+    shoppingCartId: string;
+    productItem: PricedProductItem;
+  }
+>;
+
+export type ProductItemRemovedFromShoppingCart = Event<
+  'ProductItemRemovedFromShoppingCart',
+  {
+    shoppingCartId: string;
+    productItem: PricedProductItem;
+  }
+>;
+
+export type ShoppingCartConfirmed = Event<
+  'ShoppingCartConfirmed',
+  {
+    shoppingCartId: string;
+    confirmedAt: Date;
+  }
+>;
+
+export type ShoppingCartCanceled = Event<
+  'ShoppingCartCanceled',
+  {
+    shoppingCartId: string;
+    canceledAt: Date;
+  }
+>;
+
+export type ShoppingCartEvent =
+  | ShoppingCartOpened
+  | ProductItemAddedToShoppingCart
+  | ProductItemRemovedFromShoppingCart
+  | ShoppingCartConfirmed
+  | ShoppingCartCanceled;
+
+enum ShoppingCartStatus {
+  Pending = 'Pending',
+  Confirmed = 'Confirmed',
+  Canceled = 'Canceled',
+}
+
+export type ShoppingCart = Readonly<{
+  id: string;
+  clientId: string;
+  status: ShoppingCartStatus;
+  productItems: PricedProductItem[];
+  openedAt: Date;
+  confirmedAt?: Date;
+  canceledAt?: Date;
+}>;
+
+const appendToStream = async (
+  eventStore: EventStoreDBEventStore,
+  streamName: string,
+  events: ShoppingCartEvent[],
+): Promise<bigint> => {
+  const { nextExpectedStreamVersion } = await eventStore.appendToStream(
+    streamName,
+    events,
+  );
+
+  return nextExpectedStreamVersion;
+};
+
+export const getShoppingCart = (
+  _eventStore: EventStoreDBEventStore,
+  _streamName: string,
+): Promise<ShoppingCart> => {
+  // 1. Add logic here
+  return Promise.reject(new Error('Not implemented!'));
+};
+
+describe('Events definition', () => {
+  let eventStore: EventStoreDBEventStore;
+
+  beforeAll(async () => {
+    const client = await getEventStoreDBTestClient();
+
+    eventStore = getEventStoreDBEventStore(client);
+  });
+
+  afterAll(() => releaseEventStoreDBContainer());
+
+  it('all event types should be defined', async () => {
+    const shoppingCartId = uuid();
+
+    const clientId = uuid();
+    const openedAt = new Date();
+    const confirmedAt = new Date();
+    const canceledAt = new Date();
+
+    const shoesId = uuid();
+
+    const twoPairsOfShoes: PricedProductItem = {
+      productId: shoesId,
+      quantity: 2,
+      unitPrice: 100,
+    };
+    const pairOfShoes: PricedProductItem = {
+      productId: shoesId,
+      quantity: 1,
+      unitPrice: 100,
+    };
+
+    const tShirtId = uuid();
+    const tShirt: PricedProductItem = {
+      productId: tShirtId,
+      quantity: 1,
+      unitPrice: 5,
+    };
+
+    const events: ShoppingCartEvent[] = [
+      // 2. Put your sample events here
+      {
+        type: 'ShoppingCartOpened',
+        data: {
+          shoppingCartId,
+          clientId,
+          openedAt,
+        },
+      },
+      {
+        type: 'ProductItemAddedToShoppingCart',
+        data: {
+          shoppingCartId,
+          productItem: twoPairsOfShoes,
+        },
+      },
+      {
+        type: 'ProductItemAddedToShoppingCart',
+        data: {
+          shoppingCartId,
+          productItem: tShirt,
+        },
+      },
+      {
+        type: 'ProductItemRemovedFromShoppingCart',
+        data: { shoppingCartId, productItem: pairOfShoes },
+      },
+      {
+        type: 'ShoppingCartConfirmed',
+        data: {
+          shoppingCartId,
+          confirmedAt,
+        },
+      },
+      {
+        type: 'ShoppingCartCanceled',
+        data: {
+          shoppingCartId,
+          canceledAt,
+        },
+      },
+    ];
+
+    const streamName = `shopping_cart:${shoppingCartId}`;
+
+    await appendToStream(eventStore, streamName, events);
+
+    const shoppingCart = await getShoppingCart(eventStore, streamName);
+
+    expect(shoppingCart).toBe({
+      id: shoppingCartId,
+      clientId,
+      status: ShoppingCartStatus.Canceled,
+      productItems: [pairOfShoes, tShirt],
+      openedAt,
+      confirmedAt,
+      canceledAt,
+    });
+  });
+});