fix: make lists unique via listName

libs/todos/src/adapters/dynamo-repository/dynamo.repository.ts

@@ -8,7 +8,7 @@ export default class DynamoListRepository implements ListRepository {
 
     constructor(private readonly ddb: DynamoDB.DocumentClient = new DynamoDB.DocumentClient()) { }
 
-    public async findByName(id: string): Promise<List> {
+    public async findByName(id: string): Promise<List | undefined> {
 
         const { Items: events } = await this.ddb.query({
             TableName: String(process.env.DYNAMO_TABLE_NAME),
@@ -17,7 +17,7 @@ export default class DynamoListRepository implements ListRepository {
             ExpressionAttributeNames: { "#stream": "stream" }
         }).promise();
 
-        if (!events?.length) throw new Error("[DynamoListRepository] Error: List does not exist!");
+        if (!events?.length) return;
 
         return List.buildFromStream(events as Event[]);
     }

libs/todos/src/adapters/in-memory-repository/in-memory.repository.spec.ts

@@ -21,8 +21,9 @@ describe("[InMemoryTodoGateway] Test Cases", () => {
 
 	it("should return matching list", async () => {
 		const result = await inMemTodoGW.findByName(listName)
+		expect(result).toBeDefined()
 		expect(result).toEqual(list)
-		expect.assertions(1)
+		expect.assertions(2)
 	})
 
 })

libs/todos/src/adapters/in-memory-repository/in-memory.repository.ts

@@ -6,10 +6,10 @@ export default class InMemoryTodoRepository implements ListRepository {
 
 	constructor(private readonly events: Events = new Events()) { }
 
-	public async findByName(id: string): Promise<List> {
+	public async findByName(id: string): Promise<List | undefined> {
 		const listEvents = this.events.filter((event) => event.details.id === id);
 
-		if (!listEvents.length) throw new Error("[InMemoryTodoRepository] Error: List does not exist!");
+		if (!listEvents.length) return;
 
 		return List.buildFromStream(listEvents);
 	}

libs/todos/src/commands/create-list/create-list.ts

@@ -1,6 +1,6 @@
 import { List } from "../../entities/";
 import { ListCreated } from "../../events";
-import { EventPublisher, Providers } from "../../ports";
+import { EventPublisher, ListRepository, Providers } from "../../ports";
 
 export interface CreateList {
 	execute(request: CreateListRequest): Promise<void>;
@@ -16,15 +16,21 @@ export interface CreateListRequest {
 export class CreateListImpl implements CreateList {
 
 	private publisher: EventPublisher;
+	private repository: ListRepository;
 
 	constructor(config: Providers) {
 		this.publisher = config.publisher;
+		this.repository = config.repository;
 	}
 
 	public async execute(request: CreateListRequest): Promise<void> {
 
 		const { listName: name, allowDuplicates, maxTodos, allowExpired } = request;
 
+		const existingList = await this.repository.findByName(name);
+
+		if (existingList) throw new Error("[CreateList] Error: List aleady exist!");
+
 		const newList = new List({ name, allowDuplicates, allowExpired, maxTodos });
 
 		await this.publisher.publish(new ListCreated(newList));

libs/todos/src/commands/create-todo/create-todo.ts

@@ -42,6 +42,8 @@ export class CreateTodoImpl implements CreateTodo {
 
 		const list = await this.repository.findByName(listName);
 
+		if (!list) throw new Error("[CreateTodo] Error: List does not exist!");
+
 		list.add(todo);
 
 		await this.publisher.publish(new TodoAdded(todo));

libs/todos/src/commands/delete-todo/delete-todo.ts

@@ -26,6 +26,8 @@ export class DeleteTodoImpl implements DeleteTodo {
 
 		const list = await this.repository.findByName(listName);
 
+		if (!list) throw new Error("[DeleteTodo] Error: List does not exist!");
+
 		const deletedTodo = list.remove(id)
 
 		await this.publisher.publish(new TodoRemoved(deletedTodo));

libs/todos/src/ports/list.repository.ts

@@ -1,5 +1,5 @@
 import { List } from "../entities";
 
 export default interface ListRepository {
-	findByName(name: string): Promise<List>;
+	findByName(name: string): Promise<List | undefined>;
 }