Adds better handling for dotted notation fields in is_expanded

rest_flex_fields/utils.py

@@ -10,11 +10,21 @@ def is_expanded(request, field: str) -> bool:
     expand_value = request.query_params.get(EXPAND_PARAM)
     expand_fields = []
 
-    if expand_value:
-        for f in expand_value.split(","):
-            expand_fields.extend([_ for _ in f.split(".")])
-
-    return any(field for field in expand_fields if field in WILDCARD_VALUES) or field in expand_fields
+    # first split on commas to get each expand
+    for full in expand_value.split(","):
+        # than split on dots to get each component that is expanded
+        parts = full.split(".")
+        for i in range(len(parts)):
+            # add each prefix, as each prefix is epxanded, ie
+            # a.b.c will add a, a.b and a.b.c to the expand_fields list
+            # we do this to differentiate a.b from b
+            expand_fields.append(".".join(parts[: i + 1]))
+
+    # WILDCARD_VALUES only expands top level fields
+    if "." not in field and any(field for field in expand_fields if field in WILDCARD_VALUES):
+        return True
+
+    return field in expand_fields
 
 
 def is_included(request, field: str) -> bool:

tests/test_utils.py

@@ -28,22 +28,27 @@ def test_should_not_be_included_and_due_to_fields_and_has_dot_notation(self):
         request = MockRequest(query_params={"fields": "hobby,address"})
         self.assertFalse(is_included(request, "name"))
 
-    def test_should_be_expanded(self):
-        request = MockRequest(query_params={"expand": "name,address"})
-        self.assertTrue(is_expanded(request, "name"))
-
-    def test_should_not_be_expanded(self):
-        request = MockRequest(query_params={"expand": "name,address"})
-        self.assertFalse(is_expanded(request, "hobby"))
-
-    def test_should_be_expanded_and_has_dot_notation(self):
-        request = MockRequest(query_params={"expand": "person.name,address"})
-        self.assertTrue(is_expanded(request, "name"))
-
-    def test_all_should_be_expanded(self):
-        request = MockRequest(query_params={"expand": WILDCARD_ALL})
-        self.assertTrue(is_expanded(request, "name"))
-
-    def test_asterisk_should_be_expanded(self):
-        request = MockRequest(query_params={"expand": WILDCARD_ASTERISK})
-        self.assertTrue(is_expanded(request, "name"))
+    def test_is_expanded(self):
+        test_cases = [
+            ("a", "a", True),
+            ("a", "b", False),
+            ("a,b,c", "a", True),
+            ("a,b,c", "b", True),
+            ("a,b,c", "c", True),
+            ("a,b,c", "d", False),
+            ("a.b.c", "a", True),
+            ("a.b.c", "a.b", True),
+            ("a.b.c", "a.b.c", True),
+            ("a.b.c", "b", False),
+            ("a.b.c", "c", False),
+            ("a.b.c", "d", False),
+            ("a.b.c,d", "a", True),
+            ("a.b.c,d", "d", True),
+            (WILDCARD_ASTERISK, "a", True),
+            (WILDCARD_ASTERISK, "a.b", False),
+            (WILDCARD_ALL, "a", True),
+            (WILDCARD_ALL, "a.b", False),
+        ]
+        for expand_query_arg, field, should_be_expanded in test_cases:
+            request = MockRequest(query_params={"expand": expand_query_arg})
+            self.assertEqual(is_expanded(request, field), should_be_expanded)