[🔧Chore] Codecov 및 PR CI 리포트 개선

.github/workflows/backend-ci.yml

@@ -66,6 +66,12 @@ jobs:
     runs-on: ubuntu-latest
     needs: test
     if: always()
+    outputs:
+      line_coverage: ${{ steps.coverage-summary.outputs.line_coverage }}
+      covered_lines: ${{ steps.coverage-summary.outputs.covered_lines }}
+      total_lines: ${{ steps.coverage-summary.outputs.total_lines }}
+      coverage_report_outcome: ${{ steps.download-coverage.outcome }}
+      codecov_outcome: ${{ steps.codecov.outcome }}
 
     steps:
       - name: Checkout
@@ -79,6 +85,42 @@ jobs:
           name: backend-coverage-report
           path: build/reports/jacoco/test
 
+      - name: Calculate line coverage
+        id: coverage-summary
+        if: steps.download-coverage.outcome == 'success'
+        shell: python
+        run: |
+          import os
+          from pathlib import Path
+          import xml.etree.ElementTree as ET
+
+          report = Path("build/reports/jacoco/test/jacocoTestReport.xml")
+          output = Path(os.environ["GITHUB_OUTPUT"])
+
+          line_coverage = "N/A"
+          covered_lines = "0"
+          total_lines = "0"
+
+          if report.exists():
+              root = ET.parse(report).getroot()
+              counter = next(
+                  (item for item in root.findall("counter") if item.get("type") == "LINE"),
+                  None,
+              )
+              if counter is not None:
+                  covered = int(counter.get("covered", "0"))
+                  missed = int(counter.get("missed", "0"))
+                  total = covered + missed
+                  covered_lines = str(covered)
+                  total_lines = str(total)
+                  if total > 0:
+                      line_coverage = f"{covered / total * 100:.2f}%"
+
+          with output.open("a", encoding="utf-8") as stream:
+              stream.write(f"line_coverage={line_coverage}\n")
+              stream.write(f"covered_lines={covered_lines}\n")
+              stream.write(f"total_lines={total_lines}\n")
+
       - name: Upload coverage to Codecov
         id: codecov
         if: steps.download-coverage.outcome == 'success'
@@ -102,3 +144,91 @@ jobs:
             echo "| Codecov upload | ${{ steps.codecov.outcome }} |"
             echo "| Commit | \`${{ github.sha }}\` |"
           } >> "$GITHUB_STEP_SUMMARY"
+
+  pr-report:
+    name: PR report
+    runs-on: ubuntu-latest
+    needs:
+      - test
+      - coverage
+    if: >-
+      always() &&
+      github.event_name == 'pull_request' &&
+      github.event.pull_request.head.repo.full_name == github.repository
+    permissions:
+      contents: read
+      pull-requests: write
+
+    steps:
+      - name: Update PR CI report comment
+        uses: actions/github-script@v9
+        env:
+          TEST_RESULT: ${{ needs.test.result }}
+          LINE_COVERAGE: ${{ needs.coverage.outputs.line_coverage }}
+          COVERED_LINES: ${{ needs.coverage.outputs.covered_lines }}
+          TOTAL_LINES: ${{ needs.coverage.outputs.total_lines }}
+          COVERAGE_REPORT_OUTCOME: ${{ needs.coverage.outputs.coverage_report_outcome }}
+          CODECOV_OUTCOME: ${{ needs.coverage.outputs.codecov_outcome }}
+          WORKFLOW_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
+          CODECOV_PR_URL: https://app.codecov.io/gh/${{ github.repository }}/pull/${{ github.event.pull_request.number }}
+        with:
+          script: |
+            const marker = '<!-- backend-ci-report -->';
+
+            const jobResult = (value) => ({
+              success: '✅ Passed',
+              failure: '❌ Failed',
+              cancelled: '⚪ Cancelled',
+              skipped: '⚪ Skipped',
+            })[value] ?? '⚪ Unknown';
+
+            const stepResult = (value, successLabel) => ({
+              success: `✅ ${successLabel}`,
+              failure: '⚠️ Failed',
+              cancelled: '⚪ Cancelled',
+              skipped: '⚪ Skipped',
+            })[value] ?? '⚪ Not available';
+
+            const lineCoverage = process.env.LINE_COVERAGE || 'N/A';
+            const coveredLines = process.env.COVERED_LINES || '0';
+            const totalLines = process.env.TOTAL_LINES || '0';
+
+            const body = [
+              marker,
+              '## Backend CI Report',
+              '',
+              '| Item | Result |',
+              '| --- | --- |',
+              `| Tests | ${jobResult(process.env.TEST_RESULT)} |`,
+              `| JaCoCo line coverage | ${lineCoverage} (${coveredLines}/${totalLines} lines) |`,
+              `| Coverage report | ${stepResult(process.env.COVERAGE_REPORT_OUTCOME, 'Generated')} |`,
+              `| Codecov upload | ${stepResult(process.env.CODECOV_OUTCOME, 'Uploaded')} |`,
+              '',
+              `[View workflow run](${process.env.WORKFLOW_URL}) | [View coverage details](${process.env.CODECOV_PR_URL})`,
+            ].join('\n');
+
+            const comments = await github.paginate(github.rest.issues.listComments, {
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              per_page: 100,
+            });
+            const existing = comments.find((comment) =>
+              comment.user?.login === 'github-actions[bot]' && comment.body?.includes(marker)
+            );
+
+            if (existing) {
+              await github.rest.issues.updateComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                comment_id: existing.id,
+                body,
+              });
+            } else {
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number,
+                body,
+              });
+            }

codecov.yml

@@ -1,6 +1,16 @@
+coverage:
+  status:
+    project:
+      default:
+        informational: true
+    patch:
+      default:
+        informational: true
+
 comment:
-  layout: "condensed_header, diff, files"
+  layout: "condensed_header, condensed_files, condensed_footer"
   behavior: default
   require_changes: false
   require_base: false
   require_head: true
+  hide_project_coverage: false

docs/status.md

@@ -36,6 +36,7 @@ API 계약과 API별 상태는 `docs/api/README.md`와 `docs/api/` 하위 도메
 | Issue | Scope | Status | Notes |
 |---|---|---|---|
 | [#16](https://github.com/Rewrite-Team/Rewrite-BE/issues/16) | Backend 문서 구조 및 개발 규칙 정리 | Open | 현재 문서 구조와 작업 규칙 정리 범위 |
+| [#46](https://github.com/Rewrite-Team/Rewrite-BE/issues/46) | Codecov 및 PR CI 리포트 개선 | Open | Codecov informational status, JaCoCo 수치와 Codecov 상세 링크를 포함한 고정 CI 댓글 구성 |
 
 ## Current Recommended Next Work
 

docs/testing.md

@@ -59,3 +59,14 @@ Jacoco가 설정되어 있으며, 테스트 후 `jacocoTestReport`가 실행된
 build/reports/jacoco/test/html/index.html
 build/reports/jacoco/test/jacocoTestReport.xml
 ```
+
+## Pull Request CI Report
+
+- `test` job 실패는 기존과 동일하게 PR check를 실패 처리한다.
+- Codecov project/patch status는 informational로 사용하며 커버리지 수치만 제공한다.
+- 커버리지 감소나 Codecov 업로드 실패만으로 PR 병합을 차단하지 않는다.
+- `coverage` job은 JaCoCo XML의 전체 line coverage와 Codecov 업로드 결과를 output으로 제공한다.
+- `pr-report` job은 테스트 결과, line coverage, Codecov 업로드 상태와 Codecov PR 상세 링크를 고정 댓글로 표시한다.
+- 고정 댓글은 새 workflow 실행마다 기존 `github-actions[bot]` 댓글을 갱신한다.
+- PR 코드 실행 job에는 쓰기 권한을 주지 않고, checkout을 수행하지 않는 `pr-report` job에만 `pull-requests: write`를 부여한다.
+- 외부 fork PR에서는 쓰기 토큰 제한을 고려해 고정 댓글 작성을 건너뛴다.