ci: check tests are formatted

Co-authored-by: Guilherme Soares <[email protected]>

.github/workflows/ci.yaml

@@ -25,6 +25,8 @@ jobs:
             - name: check for uncommited changes
               run: git diff --exit-code
             - run: npm test
+            - name: check test file formatting
+              run: npx tree-sitter test -u && git diff --exit-code
     prettier:
         runs-on: ubuntu-latest
         steps: