When running the test, the message "Unable to resolve all parameters for BackendService" is displayed

Upon executing the ng test command, the following error was displayed.

This is my service specification:

describe('BackendService', () => {
  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [
        {
          provide: Http, useFactory: (backend, options) => {
            return new Http(backend, options);
          },
          deps: [MockBackend, BaseRequestOptions]
        },
        MockBackend,
        BaseRequestOptions,
        BackendService
      ]
    });
  });

  it('should ...', inject([BackendService, MockBackend], (service: BackendService) => {
    expect(service).toBeTruthy();
  })

); });

The contents of BackendService.ts are as follows:

export class BackendService {
  private baseUrl: string = 'https://foo-backend.appspot.com/_ah/api/default/v1';

  constructor(private http: Http, baseName: string) {
    this.baseUrl = this.baseUrl + baseName;
  }
  .....
}

It appears that an additional parameter within the constructor of the BackendService class is causing this issue.

Answer №1

How can Angular be expected to determine the value of baseName? All constructor parameters must be provided by the Injector. Without a corresponding token for the parameter, it cannot be resolved.

In order to provide a token, you can:

// declared in some file
import { InjectionToken } from '@angular/core';

export const BASE_NAME_TOKEN = new InjectionToken("app.base_name");

// in test class
import { BASE_NAME_TOKEN } from 'wherever'

TestBed.configureTestingModule({
  providers: [
    BackendService,
    { provide: BASE_NAME_TOKEN, useValue: 'whatever-the-base-is' }
  ]
});

// in service constructor
import { Inject } from '@angular/core'
import { BASE_NAME_TOKEN } from 'wherever'

constructor(http: Http, @Inject(BASE_NAME_TOKEN) baseName: string) {}

Additional Resources:

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

hyperlink to choose a specific option from a drop-down menu

The challenge I am currently working on involves page1.html <a href="/foo"></a> foo.html <select ng-model="ctrl.listvalues"> <option id="{{item.value}}" ng-repeat="item" in ctrl.availableValues" value="{{item.value}}">item.di ...

Module not found: The system encountered an error and was unable to locate the file 'os' in the specified directory

I'm currently working on a Laravel/Vue3 project and ran into an issue. When I try to execute "npm run dev", I encounter 37 error messages. I suspect it has something to do with the mix or webpack configuration, but being unfamiliar with this area, I&a ...

Encountering intellisense problems while declaring or utilizing TypeScript types/interfaces within Vue.js Single File Component (SFC) documents

For my Nuxt 3 project, I am developing a component and attempting to declare an interface for the component props to ensure strong typings. Here is an example: <script setup> interface Props { float: number; } const props = defineProps<Props> ...

The favicon refuses to load

Image 'http://localhost:8000/favicon.ico' could not be loaded as it contravened the Content Security Policy directive "default-src 'none'". It is important to note that since 'img-src' was not specifically defined, 'defau ...

What could be causing the mousewheel event in my code to remain active?

Whenever I try to scroll on Google Chrome, an error occurs on my website. jquery-3.3.1.min.js:2 [Intervention] Unable to preventDefault inside passive event listener due to target being treated as passive. See To resolve this issue: $(document).ready(f ...

Configuring the array interval in an Angular application

I'm facing an issue while attempting to use the setInterval() function to update text for the user every 3 seconds. My attempt at looping with a for loop has not been successful - I only see 'test 03' and nothing else. I'm struggling ...

Adjusting the options in the subsequent dropdown menu based on the selection made in the initial dropdown menu

I am currently working on select boxes where values are dynamically added through an array. For example, if I have 4 values in the first select box, I only want to display 3 values in the second select box, excluding the value that has already been selecte ...

Inform the user that an error has occurred when attempting to perform an invalid

While using redux promise middleware for my front end, I am wondering about the correct status code to throw from my backend in case of an error. I know that I can use res.status(500).json(something), but is 500 the appropriate code for all types of erro ...

Storing information using ajax and json technologies

I've inherited a project where I need to work on saving data to the database using an input. The function responsible for this (SaveData) is not functioning properly. Since I'm not very familiar with ajax and json, can someone please help me iden ...

What is the best way to link the width and height of a div with form fields?

I need to implement a feature where I can create multiple div elements that are draggable and resizable, and have their properties like width, height, etc. linked to corresponding objects in an array. For example, if I create six divs, there should be six ...

Transforming dynamic class based on state value from React to TypeScript

I'm trying to implement this React function in TypeScript, but I'm encountering errors. const ListItem = ({ text }) => { let [showMore, setShowMore] = useState(false); return ( <div className="item"> ...

Creating dynamic and interactive web pages can be achieved by utilizing either $_POST or $_GET with Modal,

In the snippet below, you'll find the HTML code that pulls an array of 6 objects from a database and displays them in a Bootstrap row successfully. <div class="row products"> <?php while($product = mysqli_fetch_assoc($featured)) ...

Creating a mapping in Node.js to write to a serial port and then retrieve the

Currently, I am utilizing the node-serialport module for serial port communication. My goal is to send the command ATEC and receive a response of ECHO. However, the process of sending and receiving data is asynchronous (after sending the data, the timing ...

I am currently running a recursive loop to fetch data from MongoDB. However, the Express.js function runs through the entire script before the data can be successfully returned

Can someone assist me with setting up my Express route to handle the return of data from a recursive function that involves promises and fetching MongoDB data? Currently, my route is executing immediately without sending the data back to the client. The da ...

What is the method for implementing a custom layout for the items within a Select component?

I want to customize the options of a Select component by adding HTML elements. Here is an example: <mat-select [(ngModel)]="items"> <mat-option *ngFor="let item of ($items | async)" [value]="item.id"> <span>{{item.name}}</span&g ...

Differentiating the angular distinction between setting a variable with ng-click and invoking a function

I've encountered a situation like this before. Let's assume the controller has these variables: $scope.valueArr = ['Hello', 'No', 'Yes']; $scope.myValue = 'Hello'; And there is an ng-repeat as follows: ...

Tips on handling multiple text field validation in material-ui for react?

Currently, I am working on developing a form using Material-UI and React.js where I need to validate two TextField components. My goal is to apply the same error and textHelper props to both TextFields. Below is a snippet of my code for reference. Any sugg ...

Issues with the functionality of AngularJS checkboxes

I'm currently working on a basic AngularJS project to improve my skills. Below are the code snippets I've included. I have two sets of JSON data. One set contains a list of grocery items, while the other set includes the items selected by the us ...

Creating a dynamic trio of graphs with HTML5, CSS3, and Vanilla JavaScript

I successfully created a tree graph using HTML5 and CSS3, but currently the nodes are static. I am looking to enhance the graph by making it dynamic. By dynamic, I mean that if the number of nodes increases or there are multiple children added, the graph ...

Modify the color of the components in Select from Material-UI

After reviewing numerous questions and answers on this topic, I have yet to find a suitable solution for my issue. Seeking guidance from the community for assistance. Utilizing the Select component from @mui/material to showcase the number of records per ...