Upload artifact with pull request payload

To access information about the PR in the status embed workflow, we need
to upload an artifact whenever the forms-backend.yml workflow runs for a
`pull_request` trigger. This artifact will be downloaded in the workflow
that sends the status embed.

1 files changed, 24 insertions, 2 deletions

diff --git a/.github/workflows/forms-backend.yml b/.github/workflows/forms-backend.yml
index f7d93d2..1d7502b 100644
--- a/.github/workflows/forms-backend.yml
+++ b/.github/workflows/forms-backend.yml
@@ -2,7 +2,7 @@ name: Forms Backend
 
 on:
   push:
-    branches: 
+    branches:
       - main
   pull_request:
 
@@ -20,7 +20,7 @@ jobs:
         uses: actions/setup-python@v2
         with:
           python-version: '3.9'
-      
+
       - name: Setup Poetry
         uses: snok/[email protected]
         with:
@@ -45,6 +45,28 @@ jobs:
       - name: Run flake8
         run: "poetry run flake8 --format='::error file=%(path)s,line=%(row)d,col=%(col)d::[flake8] %(code)s: %(text)s'"
 
+      # Prepare the Pull Request Payload artifact. If this fails, we
+      # we fail silently using the `continue-on-error` option. It's
+      # nice if this succeeds, but if it fails for any reason, it
+      # does not mean that our lint-test checks failed.
+      - name: Prepare Pull Request Payload artifact
+        id: prepare-artifact
+        if: always() && github.event_name == 'pull_request'
+        continue-on-error: true
+        run: cat $GITHUB_EVENT_PATH | jq '.pull_request' > pull_request_payload.json
+
+      # This only makes sense if the previous step succeeded. To
+      # get the original outcome of the previous step before the
+      # `continue-on-error` conclusion is applied, we use the
+      # `.outcome` value. This step also fails silently.
+      - name: Upload a Build Artifact
+        if: always() && steps.prepare-artifact.outcome == 'success'
+        continue-on-error: true
+        uses: actions/upload-artifact@v2
+        with:
+          name: pull-request-payload
+          path: pull_request_payload.json
+
   build:
     name: Build & Push
     runs-on: ubuntu-latest