.github/workflows/backend-test: Add coverage report to PR comment

This adds a line to the PR comment with a collapsable toggle
so the user can click to see the full coverage report.

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

.github/workflows/backend-test.yml

@@ -64,9 +64,13 @@ jobs:
  set -x
  cd backend
  go test ./... -coverprofile=coverage.out -covermode=atomic -coverpkg=./...
+ 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)
  echo "Code coverage: $testcoverage"
+ echo "$testcoverage_full"
  echo "coverage=$testcoverage" >> $GITHUB_ENV
+ echo "testcoverage_full_base64=$testcoverage_full_base64" >> $GITHUB_ENV
  echo "cleaning up..."
  rm ~/.config/Headlamp/kubeconfigs/config
  shell: bash
@@ -125,8 +129,12 @@ jobs:
  exit 0
  fi
  testcoverage="${{ env.coverage }}"
+ testcoverage_full_base64="${{ env.testcoverage_full_base64 }}"
+ testcoverage_full=$(echo "$testcoverage_full_base64" | base64 --decode)
+
  base_coverage="${{ env.base_coverage }}"
  coverage_diff="${{ env.coverage_diff }}"
+
  if (( $(echo "$coverage_diff < 0" | bc -l) )); then
  emoji="😞" # Decreased coverage
  else
@@ -135,6 +143,21 @@ jobs:
 
  comment="Backend Code coverage changed from $base_coverage% to $testcoverage%. Change: $coverage_diff% $emoji."
  echo "$comment"
+
+ # Add the full coverage report as a collapsible section
+ comment="${comment}
+
+ <details>
+ <summary>See full coverage report</summary>
+
+ \`\`\`
+ $testcoverage_full
+ \`\`\`
+
+ </details>"
+
+ echo "$comment"
+
  if [[ "${{github.event.pull_request.head.repo.full_name}}" == "${{github.repository}}" ]]; then
  # Forks (like dependabot ones) do not have permission to comment on the PR,
  # so do not fail the action if this fails.