chore: add make option to create test coverage reports

.gitignore

@@ -34,3 +34,7 @@ go.work.sum
 
 # Unit test files
 stackit/internal/services/iaas/test-512k.img
+
+# Test coverage reports
+coverage.out
+coverage.html

CONTRIBUTION.md

@@ -26,6 +26,7 @@ These commands can be executed from the project root:
 - `make lint`: lint the code and examples
 - `make generate-docs`: generate terraform documentation
 - `make test`: run unit tests
+- `make coverage`: create unit test coverage report (output file: `stackit/coverage.html`)
 - `make test-acceptance-tf`: run acceptance tests
 
 ### Repository structure

Makefile

@@ -37,6 +37,12 @@ test:
 	@echo "Running tests for the terraform provider"
 	@cd $(ROOT_DIR)/stackit && go test ./... -count=1 && cd $(ROOT_DIR)
 
+# Test coverage
+coverage:
+	@echo ">> Creating test coverage report for the terraform provider"
+	@cd $(ROOT_DIR)/stackit && (go test ./... -count=1 -coverprofile=coverage.out || true) && cd $(ROOT_DIR)
+	@cd $(ROOT_DIR)/stackit && go tool cover -html=coverage.out -o coverage.html && cd $(ROOT_DIR)
+
 test-acceptance-tf:
 	@if [ -z $(TF_ACC_PROJECT_ID) ]; then echo "Input TF_ACC_PROJECT_ID missing"; exit 1; fi
 	@if [ -z $(TF_ACC_ORGANIZATION_ID) ]; then echo "Input TF_ACC_ORGANIZATION_ID missing"; exit 1; fi