ci: test both push and pull_request events

I think we have a bug with pull_request events so...

.forgejo/workflows/check.yml

@@ -24,18 +24,17 @@ jobs:
         uses: ./
         with:
           # Create a comment on the associated PR
-          comment-on-pr: ${{ github.ref_name != 'main' }}
+          comment-on-pr: 'false'
           # Generate artifacts on main (to speed up comparisons)
           # generate-artifact: ${{ github.ref_name == 'main' }}
           # Always generate artifacts for testing purposes
           generate-artifact: 'true'
-          # Generate comparisons to main
-          do-comparison: 'true'
-          # This job's name (so we can find the artifacts)
+          # This job's name (so we can find the previous artifacts)
           job-name: report-size
   report-download-check:
     runs-on: nixos
-    needs: report-size
+    needs: report-size-push
+    if: github.event_name == 'push'
     steps:
       - name: Download previous report
         uses: https://git.salame.cl/actions/download-artifact@d8d0a99033603453ad2255e58720b460a0555e1e # v4

.forgejo/workflows/test-pr.yml

@@ -0,0 +1,33 @@
+on:
+  pull_request:
+jobs:
+  report-size-pr:
+    runs-on: nixos
+    steps:
+      - uses: "https://git.salame.cl/actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683" # v4
+      - run: nix --version
+      - name: Create Size Report
+        uses: ./
+        with:
+          # Create a comment on the associated PR
+          comment-on-pr: 'true'
+          # Generate artifacts on main (to speed up comparisons)
+          # generate-artifact: ${{ github.ref_name == 'main' }}
+          # Always generate artifacts for testing purposes
+          generate-artifact: 'true'
+          # Generate comparisons to main
+          do-comparison: 'true'
+          # Get the previous artifacts from report-size-push (since those run on main)
+          job-name: report-size
+          artifact-name: report.json
+  report-download-check-pr:
+    runs-on: nixos
+    needs: report-size-pr
+    steps:
+      - name: Download previous report
+        uses: https://git.salame.cl/actions/download-artifact@d8d0a99033603453ad2255e58720b460a0555e1e # v4
+        with:
+          name: report.json
+      - name: Verify report exists
+        run: |
+          cat report.json

action.yml

@@ -73,6 +73,14 @@ runs:
       run: |
         . "$GITHUB_ACTION_PATH/utils.sh"
 
+        # If we were triggered by a PR then this is easy
+        if [ "$GITHUB_EVENT_NAME" = "pull_request" ]; then
+                log "Triggered by a pull request with index: $GITHUB_HEAD_REF"
+                log "Expected PR URL: $GITHUB_SERVER_URL/$GITHUB_REPOSITORY/pulls/$GITHUB_HEAD_REF"
+                echo "pr-number=$GITHUB_HEAD_REF" >> "$GIHUB_OUTPUT"
+                exit 0
+        fi
+
         log 'Determine head_ref'
         # For push & tag events it'll bet GITHUB_REF_NAME, for pull_request events it'll be GITHUB_HEAD_REF
         head_ref=${GITHUB_REF_NAME:-$GITHUB_HEAD_REF}