feat: add Codecov integration for unit test coverage (#543)

* feat: add Codecov integration for unit test coverage

- Add lcov reporter to c8 config for Codecov-compatible output
- Add Codecov upload step to test workflow with OIDC auth
- Add permissions: id-token: write for OIDC token
- Add codecov.yml with informational status checks and unit-tests flag

Ref: COVERPORT-254

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: remove hardcoded Codecov slug

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: ptomanRH

.github/workflows/test.yml

@@ -18,6 +18,8 @@ jobs:
   test:
     runs-on: ubuntu-latest
     name: Lint and test project
+    permissions:
+      id-token: write
     strategy:
       matrix:
         node: ['22', '24']
@@ -111,3 +113,11 @@ jobs:
           name: coverage
           path: ./coverage/coverage-final.json
 
+      - name: Upload coverage to Codecov
+        if: ${{ matrix.node == env.MAIN_NODE_VER }}
+        uses: codecov/codecov-action@v5
+        with:
+          use_oidc: true
+          flags: unit-tests
+          files: ./coverage/lcov.info
+

codecov.yml

@@ -0,0 +1,25 @@
+coverage:
+  status:
+    project:
+      default:
+        target: auto
+        threshold: 1%
+        informational: true
+    patch:
+      default:
+        target: auto
+        threshold: 1%
+        informational: true
+
+ignore:
+  - "node_modules/**"
+  - "dist/**"
+  - "coverage/**"
+
+flags:
+  unit-tests:
+    carryforward: true
+
+comment:
+  layout: "reach,diff,flags,files"
+  behavior: default

package.json

@@ -113,6 +113,7 @@
 		"reporter": [
 			"html",
 			"json",
+			"lcov",
 			"text"
 		]
 	},