From 71ad829c920fc95810a99d9ead17d7591695bdce Mon Sep 17 00:00:00 2001
From: Mateusz Grotek <mateusz.grotek@digital.cabinet-office.gov.uk>
Date: Tue, 25 Jun 2024 14:51:33 +0100
Subject: [PATCH] Check ruby test coverage before merging PRs

---
 .github/workflows/ci.yml                      |  7 ++++++
 .github/workflows/minitest.yml                |  7 ++++++
 .github/workflows/pact-verify.yml             |  7 ++++++
 .../store-test-coverage-percentage.yml        |  0
 .github/workflows/test-coverage.yml           | 22 +++++++++++++++++++
 lib/tasks/test_coverage.rake                  |  7 ++++++
 test/test_coverage.rb                         | 12 ++++++++++
 test/test_helper.rb                           |  4 +---
 8 files changed, 63 insertions(+), 3 deletions(-)
 create mode 100644 .github/workflows/store-test-coverage-percentage.yml
 create mode 100644 .github/workflows/test-coverage.yml
 create mode 100644 lib/tasks/test_coverage.rake
 create mode 100644 test/test_coverage.rb

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 08a813b098..932fdcdbee 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -61,3 +61,10 @@ jobs:
     uses: ./.github/workflows/pact-verify.yml
     with:
       ref: ${{ github.ref }}
+
+  test-coverage:
+    name: Check test coverage
+    needs:
+      - test-ruby
+      - pact-tests
+    uses: ./.github/workflows/test-coverage.yml
diff --git a/.github/workflows/minitest.yml b/.github/workflows/minitest.yml
index 10e4788fca..fc877d9f66 100644
--- a/.github/workflows/minitest.yml
+++ b/.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
diff --git a/.github/workflows/pact-verify.yml b/.github/workflows/pact-verify.yml
index cc36d0c5a6..f941855c82 100644
--- a/.github/workflows/pact-verify.yml
+++ b/.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
diff --git a/.github/workflows/store-test-coverage-percentage.yml b/.github/workflows/store-test-coverage-percentage.yml
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/.github/workflows/test-coverage.yml b/.github/workflows/test-coverage.yml
new file mode 100644
index 0000000000..c4323e2f64
--- /dev/null
+++ b/.github/workflows/test-coverage.yml
@@ -0,0 +1,22 @@
+name: Check test coverage
+
+on:
+  workflow_call:
+
+jobs:
+  check_ruby_test_coverage:
+    name: Check Ruby test coverage
+    runs-on: ubuntu-latest
+    steps:
+      - name: Retrieve minitest test coverage
+        uses: actions/download-artifact@v4
+        with:
+          name: minitest-test-coverage
+          path: minitest-test-coverage
+      - name: Retrieve pact test coverage
+        uses: actions/download-artifact@v4
+        with:
+          name: pact-test-coverage
+          path: pact-test-coverage
+      - name: Check Ruby test coverage
+        run: ls -R
diff --git a/lib/tasks/test_coverage.rake b/lib/tasks/test_coverage.rake
new file mode 100644
index 0000000000..1ef95ee822
--- /dev/null
+++ b/lib/tasks/test_coverage.rake
@@ -0,0 +1,7 @@
+desc "Start test coverage tool"
+task :test_coverage do
+  require_relative "../../test/test_coverage"
+end
+
+Rake::Task["pact:verify"].enhance %w[test_coverage]
+Rake::Task["pact:verify:at"].enhance %w[test_coverage]
diff --git a/test/test_coverage.rb b/test/test_coverage.rb
new file mode 100644
index 0000000000..b9212aaad3
--- /dev/null
+++ b/test/test_coverage.rb
@@ -0,0 +1,12 @@
+unless defined?(TEST_COVERAGE_ACTIVATED)
+  TEST_COVERAGE_ACTIVATED = true
+  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"
+end
diff --git a/test/test_helper.rb b/test/test_helper.rb
index fb0ff388a2..480c4941c6 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -1,6 +1,4 @@
-require "simplecov"
-SimpleCov.start "rails"
-
+require_relative "test_coverage"
 require "i18n/coverage"
 require "i18n/coverage/printers/file_printer"
 I18n::Coverage.config.printer = I18n::Coverage::Printers::FilePrinter