Run Unit tests, ITs in parallel if PR is approved. (#17611)

Instead of running the unit tests first and then running ITs, and other JDK tests, we will rather run all in parallel for faster build time. This is done only when the PR is approved so we are still not wasting gha runner bandwidth.

.github/workflows/unit-and-integration-tests-unified.yml

@@ -157,6 +157,56 @@ jobs:
           echo ${{ needs.set-env-var.outputs.DRUID_PREVIOUS_IT_IMAGE_NAME }}
           docker save "${{ needs.set-env-var.outputs.DRUID_PREVIOUS_IT_IMAGE_NAME }}" | gzip > druid-container-jdk${{ matrix.jdk }}-version${{ needs.set-env-var.outputs.DRUID_PREVIOUS_VERSION }}.tar.gz    
 
+  # check if it is a PR and if it is approved. For approved PRs, we do not want to run tests sequentially
+  check-approval:
+    runs-on: ubuntu-latest
+    outputs:
+      approved: ${{ steps.check.outputs.isApproved }}
+    steps:
+      - name: Check if Triggered by a PR
+        id: determine-trigger
+        run: |
+          if [ "${{ github.event_name }}" == "pull_request" ]; then
+            echo "isPR=true" >> $GITHUB_ENV
+          else
+            echo "isPR=false" >> $GITHUB_ENV
+          fi
+
+      - name: Check PR Approval (if applicable)
+        id: check
+        if: ${{ env.isPR == 'true' }}
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const reviews = await github.rest.pulls.listReviews({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: context.payload.pull_request.number
+            });
+            const approved = reviews.data.some(review => review.state === 'APPROVED');
+            core.setOutput("isApproved", approved);
+
+      - name: Default to Approved for Branch
+        id: default-check
+        if: ${{ env.isPR == 'false' }}
+        run: echo "::set-output name=isApproved::true"
+
+  unit-tests-unapproved:
+    name: "unit tests - PR unapproved - (jdk17)"
+    uses: ./.github/workflows/unit-tests.yml
+    needs: [build, check-approval]
+    if: ${{ needs.check-approval.outputs.approved != 'true' }}
+    with:
+      jdk: 17
+
+  unit-tests-approved:
+    name: "unit tests - PR approved - (jdk17)"
+    uses: ./.github/workflows/unit-tests.yml
+    needs: [build, check-approval]
+    if: ${{ needs.check-approval.outputs.approved == 'true' }}
+    with:
+      jdk: 17
+
   unit-tests-phase2:
     strategy:
       fail-fast: false
@@ -165,26 +215,19 @@ jobs:
         jdk: [ '11', '21.0.4' ]
     name: "unit tests (jdk${{ matrix.jdk }})"
     uses: ./.github/workflows/unit-tests.yml
-    needs: unit-tests
-    if: ${{ always() && (needs.unit-tests.result == 'success' || needs.unit-tests.outputs.continue_tests) }}
+    needs: [unit-tests-unapproved, check-approval]
+    if: ${{ always() && (needs.check-approval.outputs.approved == 'true' || needs.unit-tests-unapproved.result == 'success' || needs.unit-tests-unapproved.outputs.continue_tests) }}
     with:
       jdk: ${{ matrix.jdk }}
 
-  unit-tests:
-    name: "unit tests (jdk17)"
-    uses: ./.github/workflows/unit-tests.yml
-    needs: build
-    with:
-      jdk: 17
-
   standard-its:
-    needs: unit-tests
-    if: ${{ always() && (needs.unit-tests.result == 'success' || needs.unit-tests.outputs.continue_tests) }}
+    needs: [unit-tests-unapproved, check-approval]
+    if: ${{ always() && (needs.check-approval.outputs.approved == 'true' || needs.unit-tests-unapproved.result == 'success' || needs.unit-tests-unapproved.outputs.continue_tests) }}
     uses: ./.github/workflows/standard-its.yml
 
   revised-its:
-    needs: [unit-tests, set-env-var]
-    if: ${{ always() && (needs.unit-tests.result == 'success' || needs.unit-tests.outputs.continue_tests) }}
+    needs: [unit-tests-unapproved, check-approval, set-env-var]
+    if: ${{ always() && (needs.check-approval.outputs.approved == 'true' || needs.unit-tests-unapproved.result == 'success' || needs.unit-tests-unapproved.outputs.continue_tests) }}
     uses: ./.github/workflows/revised-its.yml
     with:
       BACKWARD_COMPATIBILITY_IT_ENABLED: ${{ needs.set-env-var.outputs.BACKWARD_COMPATIBILITY_IT_ENABLED }}