.github/workflows/backend-test: Add coverage html report

As an artifact, and link to the artifact to view in the browser.

Signed-off-by: René Dudfield <renedudfield@microsoft.com>

.github/workflows/backend-test.yml

@@ -64,6 +64,7 @@ jobs:
           set -x
           cd backend
           go test ./... -coverprofile=coverage.out -covermode=atomic -coverpkg=./...
+          go tool cover -html=coverage.out -o backend_coverage.html
           testcoverage_full=$(go tool cover -func=coverage.out)
           testcoverage=$(go tool cover -func=coverage.out | grep total | grep -Eo '[0-9]+\.[0-9]+')
           testcoverage_full_base64=$(echo "$testcoverage_full" | base64 -w 0)
@@ -75,6 +76,21 @@ jobs:
           rm ~/.config/Headlamp/kubeconfigs/config
         shell: bash
 
+      - name: Upload coverage report as artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: backend-coverage-report
+          path: ./backend/backend_coverage.html
+
+      - name: Get backend_coverage artifact URL
+        id: get-artifact-url
+        env:
+          GH_TOKEN: ${{ github.token }}        
+        run: |
+          ARTIFACT_ID=$(gh api -H "Accept: application/vnd.github.v3+json" /repos/${{ github.repository }}/actions/artifacts | jq -r '.artifacts[] | select(.name=="backend-coverage-report") | .id')
+          ARTIFACT_URL="https://github.com/${{ github.repository }}/suites/${{ github.run_id }}/artifacts/$ARTIFACT_ID"
+          echo "artifact_url=$ARTIFACT_URL" >> $GITHUB_ENV
+
       - name: Get base branch code coverage
         if: ${{ github.event_name }} == 'pull_request'
         run: |
@@ -134,6 +150,7 @@ jobs:
 
           base_coverage="${{ env.base_coverage }}"
           coverage_diff="${{ env.coverage_diff }}"
+          artifact_url="${{ env.artifact_url }}"
 
           if (( $(echo "$coverage_diff < 0" | bc -l) )); then
             emoji="😞" # Decreased coverage
@@ -148,13 +165,16 @@ jobs:
           comment="${comment}
 
           <details>
-            <summary>See full coverage report</summary>
+            <summary>Coverage report</summary>
 
           \`\`\`
           $testcoverage_full
           \`\`\`
 
-          </details>"
+          </details>
+
+          [Html coverage report download]($artifact_url)
+          "
 
           echo "$comment"