fix: throw if CustomRepository does not inherit from Base

Co-authored-by: Maximo Dominguez <[email protected]>

Author: 2 people

src/BaseFirestoreRepository.ts

@@ -29,7 +29,18 @@ import {
   SubCollectionMetadata,
 } from './MetadataStorage';
 
+/**
+ * Dummy class created with the sole purpose to be able to
+ * check if other classes are instances of BaseFirestoreRepository.
+ * Typescript is not capable to check instances of generics.
+ *
+ * @export
+ * @class BaseRepository
+ */
+export class BaseRepository {}
+
 export default class BaseFirestoreRepository<T extends IEntity>
+  extends BaseRepository
   implements IRepository<T>, IQueryBuilder<T>, IQueryExecutor<T> {
   public collectionType: FirestoreCollectionType;
   private readonly firestoreColRef: CollectionReference;
@@ -44,6 +55,7 @@ export default class BaseFirestoreRepository<T extends IEntity>
     protected readonly docId?: string,
     protected readonly subColName?: string
   ) {
+    super();
     const {
       firestoreRef,
       getCollection,

src/Decorators/CustomRepository.spec.ts

@@ -1,6 +1,7 @@
 import CustomRepository from './CustomRepository';
 import { expect } from 'chai';
 import { MetadataStorage, Initialize } from '../MetadataStorage';
+import { BaseFirestoreRepository } from '..';
 
 describe('CustomRepositoryDecorator', () => {
   const store = { metadataStorage: new MetadataStorage() };
@@ -16,14 +17,51 @@ describe('CustomRepositoryDecorator', () => {
     }
 
     @CustomRepository(Entity)
-    class EntityRepo {}
+    class EntityRepo extends BaseFirestoreRepository<Entity> {}
 
     const repository = store.metadataStorage.repositories.get(Entity);
     expect(store.metadataStorage.repositories.size).to.eql(1);
     expect(repository.entity).to.eql(Entity);
     expect(repository.target).to.eql(EntityRepo);
   });
 
-  it('should enforce that custom repository inherits from BaseRepository');
-  it('should only register a repository once');
+  it('should only register a repository once', () => {
+    class Entity {
+      id: string;
+    }
+
+    expect(() => {
+      @CustomRepository(Entity)
+      class EntityRepo extends BaseFirestoreRepository<Entity> {}
+
+      @CustomRepository(Entity)
+      class EntityRepo2 extends BaseFirestoreRepository<Entity> {}
+    }).to.throw;
+  });
+
+  it('should only register a repository once', () => {
+    class Entity {
+      id: string;
+    }
+
+    @CustomRepository(Entity)
+    @CustomRepository(Entity)
+    class EntityRepo extends BaseFirestoreRepository<Entity> {}
+
+    const repository = store.metadataStorage.repositories.get(Entity);
+    expect(store.metadataStorage.repositories.size).to.eql(1);
+    expect(repository.entity).to.eql(Entity);
+    expect(repository.target).to.eql(EntityRepo);
+  });
+
+  it('should enforce that custom repository inherits from BaseRepository', () => {
+    class Entity {
+      id: string;
+    }
+
+    expect(() => {
+      @CustomRepository(Entity)
+      class EntityRepo {}
+    }).to.throw;
+  });
 });

src/MetadataStorage.ts

@@ -1,5 +1,5 @@
-import { InstanstiableIEntity } from './types';
 import { Firestore } from '@google-cloud/firestore';
+import { BaseRepository } from './BaseFirestoreRepository';
 let store: IMetadataStore = null;
 
 export interface IMetadataStore {
@@ -60,11 +60,25 @@ export class MetadataStorage {
     this.subCollections.push(subCol);
   };
 
-  public getRepository = (param: string | InstanstiableIEntity) => {
+  public getRepository = (param: Function) => {
     return this.repositories.get(param);
   };
 
   public setRepository = (repo: RepositoryMetadata) => {
+    const savedRepo = this.getRepository(repo.entity);
+
+    if (savedRepo && repo.target !== savedRepo.target) {
+      throw new Error(
+        'Cannot register a custom repository twice with two different targets'
+      );
+    }
+
+    if (!(repo.target.prototype instanceof BaseRepository)) {
+      throw new Error(
+        'Cannot register a custom repository on a class that does not inherit from BaseFirestoreRepository'
+      );
+    }
+
     this.repositories.set(repo.entity, repo);
   };