refactor: update code style and improve ESLint rules for better consistency

test/app.e2e-spec.ts

@@ -1,25 +1,26 @@
-import { Test, TestingModule } from '@nestjs/testing';
-import { INestApplication } from '@nestjs/common';
-import request from 'supertest';
-import { App } from 'supertest/types';
-import { AppModule } from './../src/app.module';
+import type { TestingModule } from "@nestjs/testing";
+import { Test } from "@nestjs/testing";
+import type { INestApplication } from "@nestjs/common";
+import request from "supertest";
+import type { App } from "supertest/types";
+import { AppModule } from "./../src/app.module";
 
-describe('AppController (e2e)', () => {
-  let app: INestApplication<App>;
+describe("AppController (e2e)", () => {
+    let app: INestApplication<App>;
 
-  beforeEach(async () => {
-    const moduleFixture: TestingModule = await Test.createTestingModule({
-      imports: [AppModule],
-    }).compile();
+    beforeEach(async () => {
+        const moduleFixture: TestingModule = await Test.createTestingModule({
+            imports: [AppModule],
+        }).compile();
 
-    app = moduleFixture.createNestApplication();
-    await app.init();
-  });
+        app = moduleFixture.createNestApplication();
+        await app.init();
+    });
 
-  it('/ (GET)', () => {
-    return request(app.getHttpServer())
-      .get('/')
-      .expect(200)
-      .expect('Hello World!');
-  });
+    it("/ (GET)", () => {
+        return request(app.getHttpServer())
+            .get("/")
+            .expect(200)
+            .expect("Hello World!");
+    });
 });