# Unit Testing Your Application

In the previous lessons, we learned how to use [Resources & Resource Controller](https://blueprint.onehilltech.com/quick-start/my-first-application/resources-and-resource-controllers) to simplify the controllers implementation. Now, we need to test our implementation so we can ensure it is handling requests correctly.

Blueprint uses [mocha](https://mochajs.org/) and [`superagent`](https://www.npmjs.com/package/superagent) to facilitate unit testing. The benefit to Blueprint approach is it allows you to run unit tests without needing a front-end, such as Postman, to exercise the Blueprint application. You can also use [`chai`](https://www.chaijs.com/) to implement the test oracle for each unit test.

Using our current example, here is a simple unit test to check the `GET /api/rentals`.

```javascript
// tests/unit-tests/app/routers/rental.js

const { request } = require ('@onehilltech/blueprint-testing');
const { expect } = require ('chai');

describe ('app | routers | rental', function () {
  context ('GET', function () {
    it ('should get all the rentals', async function () {
      // Send a mock request to the api, and wait for the response.
      const res = await request ()
        .post ('/api/rentals')
        .expect (200);
        
      // res.body has the text from the response. 
      // From here you can use chai to implement test oracle via assertions.
    });
  });
});
```