chore: Add coverage tracking

Author: danez

.github/workflows/build.yml

@@ -37,7 +37,10 @@ jobs:
       run: yarn install --frozen-lockfile --non-interactive
 
     - name: Unit tests
-      run: yarn test --ci
+      run: yarn test --ci --coverage
+
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v2
 
   lint:
     name: Lint

.gitignore

@@ -1,4 +1,5 @@
 build/
+coverage/
 node_modules/
 npm-debug.log
 lib/