leaving notes for the future

Author: seperman

deepdiff/diff.py

@@ -845,7 +845,6 @@ def _diff_by_forming_pairs_and_comparing_one_by_one(
         t1_from_index=None, t1_to_index=None,
         t2_from_index=None, t2_to_index=None,
     ):
-
         for (i, j), (x, y) in self._get_matching_pairs(
             level, 
             t1_from_index=t1_from_index, t1_to_index=t1_to_index,
@@ -894,6 +893,8 @@ def _diff_by_forming_pairs_and_comparing_one_by_one(
                         # is relative to t2.
                         reference_param1 = j
                         reference_param2 = i
+                    else:
+                        continue
 
                 item_id = id(x)
                 if parents_ids and item_id in parents_ids:
@@ -918,6 +919,10 @@ def _diff_ordered_iterable_by_difflib(
 
         opcodes = seq.get_opcodes()
         opcodes_with_values = []
+
+        # TODO: this logic should be revisted so we detect reverse operations
+        # like when a replacement happens at index X and a reverse replacement happens at index Y
+        # in those cases we have a "iterable_item_moved" operation.
         for tag, t1_from_index, t1_to_index, t2_from_index, t2_to_index in opcodes:
             if tag == 'equal':
                 opcodes_with_values.append(Opcode(

deepdiff/helper.py

@@ -739,6 +739,7 @@ class OpcodeTag(EnumBase):
     delete = 'delete'
     equal = 'equal'
     replace = 'replace'
+    # swapped = 'swapped'  # in the future we should support reporting of items swapped with each other
 
 
 class Opcode(NamedTuple):

tests/test_diff_text.py

@@ -1744,6 +1744,15 @@ def test_list_item_removed_from_the_middle(self):
         assert {"root[4]"} == diff.affected_paths
         assert {4} == diff.affected_root_keys
 
+    # TODO: we need to support reporting that items have been swapped
+    # def test_item_moved(self):
+    #     # currently all the items in the list need to be hashables
+    #     t1 = [1, 2, 3, 4]
+    #     t2 = [4, 2, 3, 1]
+    #     diff = DeepDiff(t1, t2)
+    #     result = {}  # it should show that those items are swapped.
+    #     assert result == diff
+
     def test_list_item_values_replace_in_the_middle(self):
         t1 = [0, 1, 2, 3, 'bye', 5, 6, 7, 8, 'a', 'b', 'c']
         t2 = [0, 1, 2, 3, 'see', 'you', 'later', 5, 6, 7, 8, 'a', 'b', 'c']