fix: API endpoints input type safety

src/app.py

@@ -45,30 +45,43 @@ global_data = {'username': 'no_user'}
 # incrementation route
 @app.route('/inc')
 def plus_one():
+    try:
         x = int(request.args.get('x', 1))
+    except:
+        return json.dumps({"error": "Type error"})
+
     return json.dumps({'x': operators.addition(x, 1)})
 
 # addition route, the parameters will be passed with 'x' and 'y'
 @app.route('/add')
 def plus_y():
+    try:
         x = int(request.args.get('x', 1))
         y = int(request.args.get('y', 1))
+    except:
+        return json.dumps({"error": "Type error"})
     return json.dumps({'result': operators.addition(x, y)})
 
 
 # multiplication route, the parameters will be passed with 'x' and 'y'
 @app.route('/mul')
 def multiply_y():
+    try:
         x = int(request.args.get('x', 1))
         y = int(request.args.get('y', 1))
+    except:
+        return json.dumps({"error": "Type error"})
     return json.dumps({'result': operators.multiplication(x, y)})
 
 
 # division route, the parameters will be passed with 'x' and 'y'
 @app.route('/div')
 def division_y():
+    try:
         x = int(request.args.get('x', 1))
         y = int(request.args.get('y', 1))
+    except:
+        return json.dumps({"error": "Type error"})
     return json.dumps({'result': operators.division(x, y)})