Check ruby test coverage before merging PRs

.github/workflows/ci.yml

@@ -61,3 +61,7 @@ jobs:
     uses: ./.github/workflows/pact-verify.yml
     with:
       ref: ${{ github.ref }}
+
+  test-coverage:
+    name: Check test coverage
+    uses: ./.github/workflows/test-coverage.yml

.github/workflows/minitest.yml

@@ -47,3 +47,10 @@ jobs:
           RAILS_ENV: test
           GOVUK_CONTENT_SCHEMAS_PATH: vendor/publishing-api/content_schemas
         run: bundle exec rake test
+
+      - name: Store test coverage percentage
+        uses: actions/upload-artifact@v4
+        with:
+          name: minitest-test-coverage
+          path: coverage/percentage.txt
+          retention-days: 1

.github/workflows/pact-verify.yml

@@ -64,3 +64,10 @@ jobs:
 
       - if: inputs.pact_artifact != ''
         run: bundle exec rake pact:verify:at[tmp/pacts/${{ inputs.pact_artifact_file_to_verify }}]
+
+      - name: Store test coverage percentage
+        uses: actions/upload-artifact@v4
+        with:
+          name: pact-test-coverage
+          path: coverage/percentage.txt
+          retention-days: 1

.github/workflows/test-coverage.yml

@@ -0,0 +1,19 @@
+name: Check test coverage
+
+on:
+  workflow_call:
+
+jobs:
+  name: Check test coverage
+  runs-on: ubuntu-latest
+  steps:
+    - name: Retrieve minitest test coverage
+      uses: actions/download-artifact@v4
+      with:
+        name: minitest-test-overage
+    - name: Retrieve pact test coverage
+      with:
+        name: minitest-test-overage
+    - name: Check Ruby test coverage
+      run: ls -R
+

test/test_helper.rb

@@ -1,4 +1,11 @@
 require "simplecov"
+SimpleCov.at_exit do
+  SimpleCov.result.format!
+  File.write(
+    Rails.root.join("coverage/percentage.txt"),
+    SimpleCov.result.coverage_statistics[:line].percent.to_s,
+  )
+end
 SimpleCov.start "rails"
 
 require "i18n/coverage"