Add functional test discovery and execution

Signed-off-by: tvallin <thibault.vallin@oracle.com>

.github/workflows/openapi-generator.yaml

@@ -80,6 +80,44 @@ jobs:
           name: surefire-test-results
           path: '**/surefire-reports/TEST-*.xml'
 
+  functional-test:
+    name: Functional tests
+    runs-on: ubuntu-latest
+    needs:
+      - build
+    strategy:
+      matrix:
+        java-version: [11, 17]
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up JDK
+        uses: actions/setup-java@v3
+        with:
+          java-version: ${{ matrix.java-version }}
+          distribution: 'temurin'
+      - name: Cache maven dependencies
+        uses: actions/cache@v3
+        env:
+          cache-name: cache-maven-repository
+        with:
+          path: |
+            ~/.m2/repository
+            ~/.gradle
+            !~/.gradle/caches/*/plugin-resolution/
+            !~/.m2/repository/org/openapitools/
+          key: ${{ runner.os }}-test-${{ env.cache-name }}-${{ hashFiles('**/pom.xml') }}
+          restore-keys: |
+            ${{ runner.os }}-build-${{ env.cache-name }}-
+            ${{ runner.os }}-build-
+      - name: Run unit tests
+        run: cd modules/openapi-generator && mvn --no-snapshot-updates --batch-mode -Dtest="**/functional/*Test" test -Dorg.slf4j.simpleLogger.defaultLogLevel=error
+      - name: Publish unit test reports
+        if: ${{ always() }}
+        uses: actions/upload-artifact@v3
+        with:
+          name: surefire-test-results
+          path: '**/surefire-reports/TEST-*.xml'
+
   documentation:
     name: Docs up-to-date
     runs-on: ubuntu-latest