Attempt 1 at adding comparisons

Author: ye-spencer

.github/jobs/coverage_diff/action.yml

@@ -0,0 +1,43 @@
+# Schema: https://json.schemastore.org/github-action.json
+# This action compares coverage on a PR against a baseline stored on a branch.
+# it against the current coverage.xml, posting a comparison comment on the PR.
+name: 'Coverage Diff'
+description: 'Compare PR coverage against a baseline branch and post a summary comment on the PR'
+inputs:
+  baseline-branch:
+    description: 'Branch containing the baseline coverage.xml'
+    default: 'coverage-info'
+    required: false
+
+runs:
+  using: "composite"
+  steps:
+    - name: Fetch baseline coverage
+      id: fetch_baseline
+      shell: bash
+      run: |
+        if git fetch origin ${{ inputs.baseline-branch }} 2>/dev/null; then
+          git show origin/${{ inputs.baseline-branch }}:coverage.xml > /tmp/base-coverage.xml
+          echo "baseline_found=true" >> $GITHUB_OUTPUT
+        else
+          echo "baseline_found=false" >> $GITHUB_OUTPUT
+          echo "::warning:: Baseline branch '${{ inputs.baseline-branch }}' not found"
+        fi
+
+    - name: Run coverage diff
+      if: ${{ steps.fetch_baseline.outputs.baseline_found == 'true' }}
+      shell: bash
+      env:
+        GH_TOKEN: ${{ github.token }}
+      run: |
+        pip install pycobertura --quiet
+        DIFF_OUTPUT=$(pycobertura diff /tmp/base-coverage.xml coverage.xml --no-source --format markdown || true)
+        COMMENT_BODY=$(cat <<EOF
+        ## 📊 Coverage Diff
+        ${DIFF_OUTPUT}
+        Base: \`${{ inputs.baseline-branch }}\` · PR: \`${{ github.head_ref }}\`
+        EOF
+        )
+        echo "$COMMENT_BODY" >> $GITHUB_STEP_SUMMARY
+        echo "$COMMENT_BODY" > /tmp/coverage-comment.md
+        gh pr comment ${{ github.event.pull_request.number }} --body-file /tmp/coverage-comment.md

.github/workflows/ci_workflow.yml

@@ -52,7 +52,6 @@ jobs:
       if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
       run: genbadge coverage -i coverage.xml -o coverage-badge.svg
 
-<<<<<<< HEAD
     - name: Push badge to coverage-info branch
       if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
       env:
@@ -78,18 +77,9 @@ jobs:
         
         git commit -m "Update coverage badge [skip ci]"
         git push "https://x-access-token:${GITHUB_TOKEN}@github.com/${GITHUB_REPOSITORY}.git" coverage-info
-=======
-    - name: Push badge and summary to coverage-info branch
-      if: ${{ env.COVERAGE == 'true' && github.event_name != 'pull_request' }}
-      uses: peaceiris/actions-gh-pages@v4
-      with:
-        github_token: ${{ secrets.GITHUB_TOKEN }}
-        publish_branch: coverage-info
-        publish_dir: .
-        include_files: coverage-badge.svg, coverage.xml
-        commit_message: "Update coverage badge [skip ci]"
 
     - name: Coverage diff on PR
-      if: ${{ env.COVERAGE == 'true' && github.event_name == 'pull_request' }}
-      run: echo "TODO"
->>>>>>> cd008e2 (Outline steps I think are necessary for coverage diffs)
+
+      if: ${{ env.COVERAGE == 'true' && github.event_name == 'pull_request' && github.base_ref == 'main'}}
+      uses: ./.github/jobs/coverage_diff
+