Add cross-repo CI: trigger downstream tests on PR success

.github/workflows/trigger-downstream.yml

@@ -0,0 +1,95 @@
+name: Trigger Downstream Tests
+
+on:
+  workflow_run:
+    workflows: ["CommCare Core Build"]
+    types: [completed]
+
+jobs:
+  trigger-downstream:
+    # Only run for successful PR builds, not pushes
+    if: >
+      github.event.workflow_run.conclusion == 'success' &&
+      github.event.workflow_run.event == 'pull_request' &&
+      github.event.workflow_run.pull_requests[0]
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - repo: dimagi/commcare-android
+            check_name: "cross-repo / commcare-android"
+            workflow_file: commcare-android-pr-workflow.yml
+          - repo: dimagi/formplayer
+            check_name: "cross-repo / formplayer"
+            workflow_file: build.yml
+    steps:
+      - name: Generate GitHub App token
+        id: app-token
+        uses: actions/create-github-app-token@v1
+        with:
+          app-id: ${{ secrets.CROSS_REPO_CI_APP_ID }}
+          private-key: ${{ secrets.CROSS_REPO_CI_PRIVATE_KEY }}
+          owner: dimagi
+          repositories: commcare-core,commcare-android,formplayer
+
+      - name: Get PR info
+        id: pr
+        run: |
+          echo "sha=${{ github.event.workflow_run.head_sha }}" >> "$GITHUB_OUTPUT"
+          echo "pr_number=${{ github.event.workflow_run.pull_requests[0].number }}" >> "$GITHUB_OUTPUT"
+
+      - name: Set pending status
+        uses: actions/github-script@v7
+        env:
+          COMMCARE_CORE_SHA: ${{ steps.pr.outputs.sha }}
+          CHECK_NAME: ${{ matrix.check_name }}
+        with:
+          github-token: ${{ steps.app-token.outputs.token }}
+          script: |
+            await github.rest.repos.createCommitStatus({
+              owner: 'dimagi',
+              repo: 'commcare-core',
+              sha: process.env.COMMCARE_CORE_SHA,
+              state: 'pending',
+              context: process.env.CHECK_NAME,
+              description: 'Waiting for downstream tests...'
+            });
+
+      - name: Trigger downstream workflow
+        id: dispatch
+        uses: actions/github-script@v7
+        env:
+          COMMCARE_CORE_SHA: ${{ steps.pr.outputs.sha }}
+          COMMCARE_CORE_PR: ${{ steps.pr.outputs.pr_number }}
+          CHECK_NAME: ${{ matrix.check_name }}
+          REPO: ${{ matrix.repo }}
+          WORKFLOW_FILE: ${{ matrix.workflow_file }}
+        with:
+          github-token: ${{ steps.app-token.outputs.token }}
+          script: |
+            try {
+              const [owner, repo] = process.env.REPO.split('/');
+              await github.rest.actions.createWorkflowDispatch({
+                owner,
+                repo,
+                workflow_id: process.env.WORKFLOW_FILE,
+                ref: 'dmr/cross-repo-ci',
+                inputs: {
+                  commcare_core_sha: process.env.COMMCARE_CORE_SHA,
+                  commcare_core_pr: process.env.COMMCARE_CORE_PR,
+                  commcare_core_check_name: process.env.CHECK_NAME
+                }
+              });
+            } catch (error) {
+              // If dispatch fails, set error status so it doesn't stay pending forever
+              await github.rest.repos.createCommitStatus({
+                owner: 'dimagi',
+                repo: 'commcare-core',
+                sha: process.env.COMMCARE_CORE_SHA,
+                state: 'error',
+                context: process.env.CHECK_NAME,
+                description: `Failed to trigger: ${error.message}`.substring(0, 140)
+              });
+              throw error;
+            }