Identify untested code

Now that we have coverage on ourmain branch, let’s see how to improve our coverage. Go back toCodecov and click your demo repository. If you are not seeing any coverage information, clickConfiguration on the top right and ensure your default branch ismain.

Back on the dashboard, you will see some data relating to our recent commit. On the top is the coverage chart which will show you coverage change over time. To the right is a sunburst graph that highlights parts of the codebase that have low coverage. However, we will use the bottom section, the Fileviewer, to identify lines of code that haven’t been tested.

Click onapi andcalculator.py to see what line hasn’t been covered.

Note that we haven’t added a test for dividing by 0.

Set coverage standards

Before we add the test, let’s ensure that our coverage always hits 100%. Create a new branchstep3

git checkout maingit pullgit checkout -b 'step3'

Create a new filecodecov.yml in theroot directory of the git repository.

coverage:  status:    project:      default:        target: 100%        threshold: 1%

This configuration tells Codecov to fail a status check if 100% of the codebase is not covered with tests. However, it also allows for a 1% threshold, meaning the true minimum is 99%.

Commit the new file and open a pull request
When opening pull requests, be sure to select your own repository as the base branch.

git add .git commit -m 'step3: add project status check target'git push origin step3

You will notice that after CI finishes, we have a failing status check

Since our project still has an uncovered line, we will need to add a test to cover it before we can merge our code.

Add a test for uncovered code

At the end ofapi/calculator/tests/test_calculator.py add a test for the divide by 0 case

def test_divide_by_0():    assert Calculator.divide(2.0, 0) == 'Cannot divide by 0'

to the end of the file. Let’s commit our code again and see if our project is fully covered.

git add .git commit -m 'step3: cover divide by 0 case'git push origin step3

We now see all of our status checks passing

and the Codecov comment

shows coverage increasing in theapi/calculator.py as we expect.

Add the Codecov badge

Finally, let’s add a Codecov badge to aREADME.md file. You can copy the Markdown code from theConfiguration tab when viewing the specific repo in the Codecov UI, under theBadges & Graphs section.

YourREADME.md file will look something like

[![codecov](https://codecov.io/gh/{{REPOSITORY}}/branch/main/graph/badge.svg)](https://codecov.io/gh/{{REPOSITORY}})

As before, commit the changes and merge the pull request

git add .git commit -m 'step3: add Codecov badge'git push origin step3

You should see the badge appear on the repository screen in GitHub

Updated 10 months ago