Understanding and Using Codecov
Codecov is an automated code coverage reporting tool integrated with our GitHub repository. It provides detailed insights into which parts of our codebase are covered by tests — across both R and JavaScript files.
The coverage for the master branch (and all other branches) is shown here:
Codecov Dashboard – animint2
- Scroll down to access the File Explorer view.
- This section shows all R and JS files along with their individual coverage percentages.
- Clicking on a specific file will open a view that highlights:
- ✅ Lines covered by tests.
- ❌ Lines missed by tests.
This makes it easy to identify untested code.
You can change the selected branch at the top of the dashboard to view its test coverage.
For each branch, Codecov provides:
- Overall project coverage %
- File-by-file coverage
- Per-line insights on what's tested vs. what's not
Use this to assess how much your changes impact test coverage.
Whenever you open a Pull Request, Codecov automatically:
- Analyzes the diff and overall coverage changes.
- Posts a comment in the PR with:
- Whether coverage increased or decreased
- Which files were affected
- Line-level insights (newly missed or covered lines)
for example:
- Look at the Codecov PR comment.
- Identify the missing lines or files with poor coverage.
- Try writing tests that hit those lines.
- Commit your test — Codecov will re-run and update the coverage comment automatically.
- Observe how much your test increased coverage.
Codecov is a feedback loop for test coverage:
- Use it to find gaps in testing.
- Write targeted tests for missed lines.
- Monitor progress as coverage improves with each commit.