Reading Single Artists

We can now serve a list of all artists to the client. What if the client wants to find out the details of a single artist? They could retrieve the entire list and search through it themselves - but we can make the process much more efficient by adding a new endpoint to get the desired records directly from the database.

Start by adding new tests to tests/artist-read.test.js:

// artist-read.test.js
...
  describe('GET /artists/{id}', () => {
    it('returns the artist with the correct id', async () => {
      const { status, body } = await request(app).get(`/artists/${artists[0].id}`).send()
 
      expect(status).to.equal(200)
      expect(body).to.deep.equal(artists[0])
    })
 
    it('returns a 404 if the artist does not exist', async () => {
      const { status, body } = await request(app).get('/artists/999999999').send()
 
      expect(status).to.equal(404)
      expect(body.message).to.equal('artist 999999999 does not exist')
    })
  })
...

The first test is just looking to see if the returned artist details match artist 0 from the artists array.

The second test is asking for an artist that doesn't exist, and expects to get a 404 status code back.

Getting an artist by Id

Passing this test shouldn't be too difficult. You will need to start by defining a new GET route which matches path /artists/:id. You'll then need to write a controller which uses db.query() to SELECT everything from the artist table WHERE the id matches req.params.id.

There is a gotcha in this challenge, db.query() will still return single results in an array. To pass the test you will need to remove it from the array before you send the data in the response.

Returning a 404

To pass this test, you will need to check the truthyness of the artist after you get it from the database. If it is truthy then send it back to the user as normal. If the artist is falsy, you will need to send a 404 status code instead.

You can see a solution to these two challenges here.