Add pre-push hook

.github/workflows/dotnet-core.yaml

@@ -26,4 +26,4 @@ jobs:
     - name: Install Fantomas
       run: dotnet tool restore
     - name: Run Fantomas
-      run: dotnet tool run fantomas --check -r .
+      run: ./hooks/pre-push

hooks/pre-push

@@ -0,0 +1,17 @@
+#!/usr/bin/env python3
+
+import subprocess
+
+def check_fantomas():
+    result = subprocess.run(["dotnet", "tool", "run", "fantomas", "--check", "-r", "."])
+    if result.returncode != 0:
+        print(result.stdout)
+        raise Exception(f"Formatting incomplete (return code: {result.returncode}). Consider running `dotnet tool run fantomas -r .`")
+
+
+def main():
+    check_fantomas()
+
+
+if __name__ == "__main__":
+    main()