Smarter Testing

March 14, 2020

When I first wrote the code and tests in note.go and note_test.go, I wanted to see if I could get to 100% code coverage. It's a good exercise if you've never done it before to see what you have to do to get there. It requires a lot more effort than it's worth for most applications, but still a good exercise. View commit.

In Go, table driven tests is very common. You can read able them here. It helps cut down on all the boilerplate code you have to repeat everywhere.

It's also helpful if you have a setup and teardown process that is run with each of your tests. Since that code was copy and pasted in many different places, considated they to easy to use functions. View commit.

Code samples below.

Before

Before the refactor, the code looked like this in many of the test functions. This test ensures that a user can register themselves as a new user.

func TestRegisterSuccess(t *testing.T) {
    db := testutil.LoadDatabase()
    defer testutil.TeardownDatabase(db)
    p, _ := testutil.Services(db)
    tr := testrequest.New()

    // Register the user.
    form := url.Values{}
    form.Set("first_name", "Foo")
    form.Set("last_name", "Bar")
    form.Set("email", "fbar@example.com")
    form.Set("password", "guess123")
    w := tr.SendJSON(t, p, "POST", "/api/v1/register", form)

    // Verify the response.
    r := new(model.CreatedResponse)
    err := json.Unmarshal(w.Body.Bytes(), &r.Body)
    assert.Nil(t, err)
    assert.Equal(t, http.StatusCreated, w.Code)
    assert.Equal(t, 36, len(r.Body.RecordID))
}

After

Notice the boilerplate code at the top of the function has been consolidated to a few functions. It's also more clear that teardown will happen at the end for everything that was setup whereas in the old code, it was a little confusing on what was actually being set up and torn down.

Also, notice the asserts at the bottom of the function have been moved into a separate function since there are many tests that will use the same test logic.

func TestRegisterSuccess(t *testing.T) {
    c := testutil.Setup()
    defer c.Teardown()

    // Register the user.
    form := url.Values{}
    form.Set("first_name", "Foo")
    form.Set("last_name", "Bar")
    form.Set("email", "fbar@example.com")
    form.Set("password", "password")
    w := c.Request.SendJSON(t, c.Core, "POST", "/api/v1/register", form)
    r := testutil.EnsureCreated(t, w)
    assert.Equal(t, 36, len(r.Body.RecordID))
}