Add code coverage collection and Codecov badge (#39)

* Initial plan

* Add code coverage collection and Codecov badge

Co-authored-by: dex3r <3155725+dex3r@users.noreply.github.com>

* Update .github/workflows/ci.yml

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: dex3r <3155725+dex3r@users.noreply.github.com>
Co-authored-by: Mateusz Krzaczek <dex3r@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: 3 people

.github/workflows/ci.yml

@@ -23,4 +23,10 @@ jobs:
         run: dotnet restore MattSourceGenHelpers.sln
 
       - name: Test
-        run: dotnet test MattSourceGenHelpers.sln --no-restore --verbosity normal
+        run: dotnet test MattSourceGenHelpers.sln --no-restore --verbosity normal --collect:"XPlat Code Coverage" --results-directory ./coverage
+
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v5
+        with:
+          directory: ./coverage
+          fail_ci_if_error: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}

README.md

@@ -1,5 +1,7 @@
 # MattSourceGenHelpers
 
+[![codecov](https://codecov.io/gh/dex3r/MattSourceGenHelpers/branch/main/graph/badge.svg)](https://codecov.io/gh/dex3r/MattSourceGenHelpers)
+
 With MattSourceGenHelpers, you can write your generator code as a normal method, in the same assembly as the output.
 This allows you to write your generator in a more natural way, without having to deal with the complexities of Roslyn Source Generators and a separate Project.