Code review changes (removed safe_dict_descend)

lbrynet/core/utils.py

@@ -134,31 +134,15 @@ def get_sd_hash(stream_info):
         return None
     if isinstance(stream_info, ClaimDict):
         return stream_info.source_hash
-    path = ['claim', 'value', 'stream', 'source', 'source']
-    result = safe_dict_descend(stream_info, *path)
+    result = stream_info.get('claim', {}).\
+        get('value', {}).\
+        get('stream', {}).\
+        get('source', {}).\
+        get('source')
     if not result:
-        log.warn("Unable to get sd_hash via path %s" % path)
+        log.warn("Unable to get sd_hash")
     return result
 
 
 def json_dumps_pretty(obj, **kwargs):
     return json.dumps(obj, sort_keys=True, indent=2, separators=(',', ': '), **kwargs)
-
-
-def safe_dict_descend(source, *path):
-    """
-    For when you want to do something like
-    stream_info['claim']['value']['stream']['source']['source']"
-    but don't trust that every last one of those keys exists
-    """
-    cur_source = source
-    for path_entry in path:
-        try:
-            if path_entry not in cur_source:
-                return None
-        except TypeError:
-            # This happens if we try to keep going along a path that isn't
-            # a dictionary (see e.g. test_safe_dict_descend_typeerror)
-            return None
-        cur_source = cur_source[path_entry]
-    return cur_source

lbrynet/tests/unit/core/test_utils.py

@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 from lbrynet.core import utils
+from lbryschema.claim import ClaimDict
 
 from twisted.trial import unittest
 
@@ -33,45 +34,31 @@ class ObfuscationTest(unittest.TestCase):
         self.assertEqual(plain, utils.deobfuscate(obf))
 
 
-class SafeDictDescendTest(unittest.TestCase):
+class SdHashTests(unittest.TestCase):
 
-    def test_safe_dict_descend_happy(self):
-        nested = {
-            'foo': {
-                'bar': {
-                    'baz': 3
+    def test_none_in_none_out(self):
+        self.assertIsNone(utils.get_sd_hash(None))
+
+    def test_ordinary_dict(self):
+        claim = {
+            "claim": {
+                "value": {
+                    "stream": {
+                        "source": {
+                            "source": "0123456789ABCDEF"
+                        }
+                    }
                 }
             }
         }
-        self.assertEqual(
-            utils.safe_dict_descend(nested, 'foo', 'bar', 'baz'),
-            3
-        )
+        self.assertEqual("0123456789ABCDEF", utils.get_sd_hash(claim))
 
-    def test_safe_dict_descend_typeerror(self):
-        nested = {
-            'foo': {
-                'bar': 7
+    def test_old_shape_fails(self):
+        claim = {
+            "stream": {
+                "source": {
+                    "source": "0123456789ABCDEF"
+                }
             }
         }
-        self.assertIsNone(utils.safe_dict_descend(nested, 'foo', 'bar', 'baz'))
-
-    def test_safe_dict_descend_missing(self):
-        nested = {
-            'foo': {
-                'barn': 7
-            }
-        }
-        self.assertIsNone(utils.safe_dict_descend(nested, 'foo', 'bar', 'baz'))
-
-    def test_empty_dict_doesnt_explode(self):
-        nested = {}
-        self.assertIsNone(utils.safe_dict_descend(nested, 'foo', 'bar', 'baz'))
-
-    def test_identity(self):
-        nested = {
-            'foo': {
-                'bar': 7
-            }
-        }
-        self.assertIs(nested, utils.safe_dict_descend(nested))
+        self.assertIsNone(utils.get_sd_hash(claim))