Chapter 7: Codecov Test Coverage

In this chapter, you will add a Codecov Test Coverage CI badge to your source code. This lets you or anyone else see the test coverage without having to set up the app locally. I prefer Codecov because it's easy to work with and is available for BitBucket and GitLab as well as GitHub.

Entering Your App on the Codecov Web Site

Go to the Codecov web site. Sign up if you have not already done so.
Select your new Rails app as one to be monitored.
Codecov gives you a repo token. This is used in your continuous integration build app to send its test coverage results to the Codecov service so that it can produce a test coverage badge.
Go back to the Travis CI web site. Add the environment variable "CODECOV_TOKEN", and set it to the value provided by Codecov. In the interest of security, do NOT set the option to display its value in the build log.

Generic App Users

If the Generic App Tutorial sent you here, follow these steps:

Go back to the Travis CI web site and restart the build.
You can skip the "Updating the Gemfile" and the "Updating the Test Helper File" sections. The changes listed here have already been done for you.
Skip ahead to the "Running CodeCov" section.

Updating the Gemfile

In the "test coverage" section of the Gemfile, add the following line:

gem 'codecov', require: false, group: :test

Enter the command "bundle install".
Enter the command "gem list codecov" to see which version of codecov is installed. Pin the codecov gem in the Gemfile.
Enter the command "bundle install".

Updating the Test Helper File

In the test/test_helper.rb file, add the following lines immediately after the SimpleCov section:

# BEGIN: Codecov
# Run Codecov ONLY in continuous integration.
# Running Codecov suppresses the display of the test coverage percentage
# in the terminal screen output.
if ENV.include? 'CODECOV_TOKEN'
  require 'codecov'
  SimpleCov.formatter = SimpleCov::Formatter::Codecov
end
# END: Codecov

In the test/test_helper.rb file, update the "minitest-reporters" section. In the Travis CI environment, Codecov conflicts with the Minitest Reporters and leads to an uninitialized constant error and a failed build. You must disable Minitest Reporters in the Travis environment. Edit the test/test_helper.rb file and make the following changes:
- Replace the "NOTE" line with the following:
```
# NOTE: Minitest Reporters is incompatible with GitLab CI and Codecov.
```
- Replace the "if" line with the following:
```
if ENV['GITLAB_CI'].nil? && ENV['CODECOV_TOKEN'].nil?
```
Enter the command "sh git_check.sh". All tests should pass, and there should be no offenses.
Enter the following commands:

git add .
git commit -m "Added codecov"
git push origin master

Running Codecov

If all goes well, all tests will pass, and a test coverage figure will be reported to Codecov. (It should be the same value that SimpleCov is giving you in your local setup.)
Add the Markdown code for the Codecov test coverage badge to the README.md file.
To commit the Codecov badge to the source code, enter the following commands:

git add .
git commit -m "Added the Codecov badge"
git push origin master

Enter the command "sh heroku.sh".
The Travis CI badge should appear on the README.md page in GitHub. You may need to refresh your web browser.