test(test-utils): add codecov coverage (#6051)

.github/workflows/unit-test.yml

@@ -32,4 +32,8 @@ jobs:
       - name: Lint
         run: pnpm lint
       - name: Test
-        run: pnpm test
+        run: pnpm test -- --coverage
+      - name: Upload to codecov.io
+        uses: codecov/codecov-action@v2
+        with:
+          fail_ci_if_error: true

codecov.yml

@@ -0,0 +1,9 @@
+coverage:
+  status:
+    project:
+      default:
+        target: auto
+        threshold: 10%
+comment:
+  layout: 'reach, diff, flags, files'
+  require_changes: true