Update app.py

Added ensure_tool definition

app.py

@@ -31,7 +31,15 @@ wandb.init(
 HF_TOKEN = os.getenv("HF_API_TOKEN")
 client = InferenceClient(model="declare-lab/flan-alpaca-gpt4", token=HF_TOKEN)
 
+def ensure_tool(name: str):
+    if shutil.which(name) is None:
+        print(f"Error: `{name}` not found. Please install it and retry.", file=sys.stderr)
+        sys.exit(1)
+
 def run_cppcheck(source_code: str):
+    # Check for the code checker tool
+    ensure_tool("cppcheck")
+
     # Write uploaded code to temp file
     tf = NamedTemporaryFile(suffix=".cpp", delete=False)
     tf.write(source_code.encode())