ci: add coverage options to ci test

.github/.codecov.yml

@@ -0,0 +1,27 @@
+# To validate:
+#   cat codecov.yml | curl --data-binary @- https://codecov.io/validate
+
+codecov:
+  notify:
+    require_ci_to_pass: yes
+
+coverage:
+  precision: 2
+  round: down
+  range: "70...100"
+
+  status:
+    project:
+      default:
+        target: auto
+        threshold: 0%
+        informational: true
+    patch:
+      default:
+        enabled: no
+        if_not_found: success
+
+comment:
+  layout: "reach, diff, files, flags"
+  behavior: default
+  require_changes: no

.github/workflows/build.yaml

@@ -67,8 +67,19 @@ jobs:
       - name: Run tests
         run: |
           if grep -q "name: example" "pubspec.yaml"; then
-            flutter test
+            flutter test --coverage
           else
-            dart test
+            dart test --coverage=./coverage
+            dart run coverage:format_coverage --lcov --in=./coverage --out=./coverage/lcov.info --report-on=lib
           fi
         working-directory: ${{ matrix.package }}
+
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: ./coverage/lcov.info
+          fail_ci_if_error: true
+          flags: unittests
+          name: codecov-umbrella
+          working-directory: ${{ matrix.package }}