Code Coverage Report
Generate a code coverage report scoped to source files changed in the current branch compared to a base branch.
Workflow
1. Determine base branch
Detect the base branch to diff against. Use the MR/PR target branch if known, otherwise default to main or master (whichever exists). Ask the user if ambiguous.
git merge-base --fork-point main HEAD || git merge-base --fork-point master HEAD
2. Detect changed source files
git diff <base-branch> --name-only -- '*.cs'
Filter out test files (paths containing Test, Tests, .Tests, .Test).
If no source files changed, stop and inform the user.
3. Identify test project(s)
Determine which test project(s) to run. Strategies (in order):
- User-specified: If the user names a test project, use it
- Convention-based: Look for test projects whose name matches the changed project (e.g.,
MyProject->MyProject.Tests) - Solution-wide: Run all tests in the solution if scope is unclear
- Ask: If ambiguous, ask the user which test project(s) to run
4. Clean previous results
rm -rf TestResults/
5. Run tests with coverage
dotnet test <test-project-or-solution> \
--collect:"XPlat Code Coverage" \
--results-directory ./TestResults/
6. Build file filters
From the changed file list (step 2), extract basenames and build a filter string:
+*FileName1.cs;+*FileName2.cs;+*FileName3.cs
7. Generate report
dotnet reportgenerator \
-reports:"TestResults/**/coverage.cobertura.xml" \
-targetdir:"TestResults/CoverageReport" \
-reporttypes:"Html;TextSummary" \
-filefilters:"<filters>"
8. Display results
- Print
TestResults/CoverageReport/Summary.txtto the terminal - Open the HTML report (platform-aware):
- Windows:
start TestResults/CoverageReport/index.html - macOS:
open TestResults/CoverageReport/index.html - Linux:
xdg-open TestResults/CoverageReport/index.html
- Windows:
Tips
- For large solutions, scope to specific test projects to speed up collection
- The
-filefiltersflag accepts wildcards -- basename matching avoids path sensitivity