Raise error if no search term provided for search endpoint (#5441)

- Also adjust unit testing

InvenTree/InvenTree/api.py

@@ -287,6 +287,11 @@ class APISearchView(APIView):
             'offset': 0,
         }
 
+        if 'search' not in data:
+            raise ValidationError({
+                'search': 'Search term must be provided',
+            })
+
         for key, cls in self.get_result_types().items():
             # Only return results which are specifically requested
             if key in data:

InvenTree/InvenTree/test_api.py

@@ -316,6 +316,19 @@ class SearchTests(InvenTreeAPITestCase):
         'sales_order',
     ]
 
+    def test_empty(self):
+        """Test empty request"""
+
+        data = [
+            '',
+            None,
+            {},
+        ]
+
+        for d in data:
+            response = self.post(reverse('api-search'), d, expected_code=400)
+            self.assertIn('Search term must be provided', str(response.data))
+
     def test_results(self):
         """Test individual result types"""