fix: revise and rename is_etag_in_json(data)

google/cloud/storage/retry.py

@@ -18,8 +18,6 @@
 from google.api_core import retry
 from google.auth import exceptions as auth_exceptions
 
-import json
-
 
 # ConnectionError is a built-in exception only in Python3 and not in Python2.
 try:
@@ -123,17 +121,11 @@ def is_metageneration_specified(query_params):
 def is_etag_in_json(data):
     """Return True if an etag is contained in the JSON body.
 
-    Indended for use on calls with relatively short JSON payloads."""
-    try:
-        content = json.loads(data)
-        if content.get("etag"):
-            return True
-    # Though this method should only be called when a JSON body is expected,
-    # the retry policy should be robust to unexpected payloads.
-    # In Python 3 a JSONDecodeError is possible, but it is a subclass of ValueError.
-    except (ValueError, TypeError):
-        pass
-    return False
+    :type data: dict or None
+    :param data: A dict representing the JSON body. If not passed, returns False.
+
+    Intended for use on calls with relatively short JSON payloads."""
+    return data is not None and "etag" in data
 
 
 DEFAULT_RETRY_IF_GENERATION_SPECIFIED = ConditionalRetryPolicy(

tests/unit/test_retry.py

@@ -172,24 +172,18 @@ def _call_fut(self, data):
 
         return retry.is_etag_in_json(data)
 
-    @staticmethod
-    def _make_json_data(**kw):
-        import json
-
-        return json.dumps(kw)
-
-    def test_w_empty(self):
-        data = self._make_json_data()
+    def test_w_none(self):
+        data = None
 
         self.assertFalse(self._call_fut(data))
 
     def test_w_etag_in_data(self):
-        data = self._make_json_data(etag="123")
+        data = {"etag": "123"}
 
         self.assertTrue(self._call_fut(data))
 
     def test_w_empty_data(self):
-        data = ""
+        data = {}
 
         self.assertFalse(self._call_fut(data))