test(core): add tests for nested transient structures

integration/scopes/e2e/transient-scope.spec.ts

@@ -1,4 +1,4 @@
-import { INestApplication, Scope } from '@nestjs/common';
+import { INestApplication, Injectable, Scope } from '@nestjs/common';
 import { Test } from '@nestjs/testing';
 import { expect } from 'chai';
 import * as request from 'supertest';
@@ -17,7 +17,8 @@ class Meta {
 }
 
 describe('Transient scope', () => {
-  let server;
+  describe('when transient scope is used', () => {
+    let server: any;
     let app: INestApplication;
 
     before(async () => {
@@ -36,7 +37,7 @@ describe('Transient scope', () => {
       await app.init();
     });
 
-  describe('when one service is request scoped', () => {
+    describe('and when one service is request scoped', () => {
       before(async () => {
         const performHttpCall = end =>
           request(server)
@@ -78,4 +79,64 @@ describe('Transient scope', () => {
     after(async () => {
       await app.close();
     });
+  });
+
+  describe('when there is a nested structure of transient providers', () => {
+    let app: INestApplication;
+
+    @Injectable({ scope: Scope.TRANSIENT })
+    class DeepTransient {
+      public initialized = false;
+
+      constructor() {
+        this.initialized = true;
+      }
+    }
+
+    @Injectable({ scope: Scope.TRANSIENT })
+    class LoggerService {
+      public context?: string;
+    }
+
+    @Injectable({ scope: Scope.TRANSIENT })
+    class SecondService {
+      constructor(public readonly loggerService: LoggerService) {
+        this.loggerService.context = 'SecondService';
+      }
+    }
+
+    @Injectable()
+    class FirstService {
+      constructor(
+        public readonly secondService: SecondService,
+        public readonly loggerService: LoggerService,
+        public readonly deepTransient: DeepTransient,
+      ) {
+        this.loggerService.context = 'FirstService';
+      }
+    }
+
+    before(async () => {
+      const module = await Test.createTestingModule({
+        providers: [FirstService, SecondService, LoggerService, DeepTransient],
+      }).compile();
+
+      app = module.createNestApplication();
+      await app.init();
+    });
+
+    it('should create a new instance of the transient provider for each provider', async () => {
+      const firstService1 = app.get(FirstService);
+
+      expect(firstService1.secondService.loggerService.context).to.equal(
+        'SecondService',
+      );
+      expect(firstService1.loggerService.context).to.equal('FirstService');
+      expect(firstService1.deepTransient.initialized).to.be.true;
+    });
+
+    after(async () => {
+      await app.close();
+    });
+  });
 });