diff --git a/src/app/shared/services/http-server.service.spec.ts b/src/app/shared/services/http-server.service.spec.ts
index 75923814..90cbeb7c 100644
--- a/src/app/shared/services/http-server.service.spec.ts
+++ b/src/app/shared/services/http-server.service.spec.ts
@@ -1,15 +1,115 @@
-import { TestBed, inject } from '@angular/core/testing';
+import { TestBed,  } from '@angular/core/testing';
+import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';
+import { HttpClient } from "@angular/common/http";
 
+import { Server } from '../models/server';
 import { HttpServer } from './http-server.service';
 
+
 describe('HttpServer', () => {
+  let httpClient: HttpClient;
+  let httpTestingController: HttpTestingController;
+  let service: HttpServer;
+  let server: Server;
+
   beforeEach(() => {
     TestBed.configureTestingModule({
-      providers: [HttpServer]
+      imports: [
+        HttpClientTestingModule
+      ],
+      providers: [
+        HttpServer
+      ]
     });
+
+    httpClient = TestBed.get(HttpClient);
+    httpTestingController = TestBed.get(HttpTestingController);
+    service = TestBed.get(HttpServer);
+
+    server = new Server();
+    server.ip = "127.0.0.1";
+    server.port = 3080;
+    server.authorization = "none";
   });
 
-  // it('should be created', inject([HttpServer], (service: HttpServer) => {
-  //   expect(service).toBeTruthy();
-  // }));
+  afterEach(() => {
+    httpTestingController.verify();
+  });
+
+  it('should make GET query for get method', () => {
+    service.get(server, '/test').subscribe();
+
+    const req = httpTestingController.expectOne('http://127.0.0.1:3080/v2/test');
+    expect(req.request.method).toEqual("GET");
+    expect(req.request.responseType).toEqual("json");
+  });
+
+  it('should make GET query for getText method', () => {
+    service.getText(server, '/test').subscribe();
+
+    const req = httpTestingController.expectOne('http://127.0.0.1:3080/v2/test');
+    expect(req.request.method).toEqual("GET");
+    expect(req.request.responseType).toEqual("text");
+  });
+
+  it('should make POST query for post method', () => {
+    service.post(server, '/test', {test: "1"}).subscribe();
+
+    const req = httpTestingController.expectOne('http://127.0.0.1:3080/v2/test');
+    expect(req.request.method).toEqual("POST");
+    expect(req.request.responseType).toEqual("json");
+  });
+
+  it('should make PUT query for put method', () => {
+    service.put(server, '/test', {test: "1"}).subscribe();
+
+    const req = httpTestingController.expectOne('http://127.0.0.1:3080/v2/test');
+    expect(req.request.method).toEqual("PUT");
+    expect(req.request.responseType).toEqual("json");
+  });
+
+  it('should make DELETE query for delete method', () => {
+    service.delete(server, '/test').subscribe();
+
+    const req = httpTestingController.expectOne('http://127.0.0.1:3080/v2/test');
+    expect(req.request.method).toEqual("DELETE");
+    expect(req.request.responseType).toEqual("json");
+  });
+
+  it('should make PATCH query for patch method', () => {
+    service.patch(server, '/test', {test: "1"}).subscribe();
+
+    const req = httpTestingController.expectOne('http://127.0.0.1:3080/v2/test');
+    expect(req.request.method).toEqual("PATCH");
+    expect(req.request.responseType).toEqual("json");
+  });
+
+  it('should make HEAD query for head method', () => {
+    service.head(server, '/test').subscribe();
+
+    const req = httpTestingController.expectOne('http://127.0.0.1:3080/v2/test');
+    expect(req.request.method).toEqual("HEAD");
+    expect(req.request.responseType).toEqual("json");
+  });
+
+  it('should make OPTIONS query for options method', () => {
+    service.options(server, '/test').subscribe();
+
+    const req = httpTestingController.expectOne('http://127.0.0.1:3080/v2/test');
+    expect(req.request.method).toEqual("OPTIONS");
+    expect(req.request.responseType).toEqual("json");
+  });
+
+  it('should add headers for `basic` authorization', () => {
+    server.authorization = "basic";
+    server.login = "login";
+    server.password = "password";
+
+    service.get(server, '/test').subscribe();
+
+    const req = httpTestingController.expectOne('http://127.0.0.1:3080/v2/test');
+    expect(req.request.method).toEqual("GET");
+    expect(req.request.responseType).toEqual("json");
+    expect(req.request.headers.get('Authorization')).toEqual('Basic bG9naW46cGFzc3dvcmQ=');
+  });
 });
diff --git a/src/app/shared/services/http-server.service.ts b/src/app/shared/services/http-server.service.ts
index d89d628b..d9aee35d 100644
--- a/src/app/shared/services/http-server.service.ts
+++ b/src/app/shared/services/http-server.service.ts
@@ -114,8 +114,8 @@ export class HttpServer {
   private getOptionsForServer<T extends HeadersOptions>(server: Server, url: string, options: T) {
     url = `http://${server.ip}:${server.port}/v2${url}`;
 
-    if (options.headers === null) {
-      options.headers = new HttpHeaders();
+    if (!options.headers) {
+      options.headers = {};
     }
 
     if (server.authorization === "basic") {