feat: add count method

src/DocumentCollection.ts

@@ -36,4 +36,8 @@ export class DocumentCollection<DocumentType> {
 
     return documents
   }
+
+  count(): number {
+    return this.documents.size
+  }
 }

src/Store.ts

@@ -52,6 +52,10 @@ export class Store<TypesMap extends Record<string, any>> {
     return this.collections.get(type).find(predicate)
   }
 
+  count<Type extends keyof TypesMap>(type: Type): number {
+    return this.collections.get(type).count()
+  }
+
   reset(): void {
     this.collections = new CollectionStorage<TypesMap>(this.schema)
   }

tests/count.test.ts

@@ -0,0 +1,21 @@
+import { Store } from '../src'
+import { schema, TypesMap } from './fixtures'
+import { toCollection } from './utils'
+import { postFactory, userFactory } from './utils/factories'
+
+const store = new Store<TypesMap>({
+  schema,
+})
+
+afterEach(() => store.reset())
+
+it('should return the count of stored documents for given type', () => {
+  expect(store.count('User')).toEqual(0)
+  expect(store.count('Post')).toEqual(0)
+
+  toCollection(() => store.create('User', userFactory()), 5)
+  toCollection(() => store.create('Post', postFactory()), 5)
+
+  expect(store.count('User')).toEqual(5)
+  expect(store.count('Post')).toEqual(5)
+})