DiffTool: Add patch for DeepDiff to not use default diff function for iterables

Because of recursive diff for iterables which provides with ugly unified_diff, we
patched the DeepDiff class to treat iterables as string itself and then generate
a unified diff which could be displayed in ERP5.

product/ERP5/bootstrap/erp5_core/DocumentTemplateItem/portal_components/document.erp5.DiffTool.py

@@ -42,6 +42,7 @@ except ImportError:
   warnings.warn("Please install unidiff, it is needed by Diff Tool",
                 DeprecationWarning)
 from AccessControl import ClassSecurityInfo
+from Products.ERP5Type.patches.diff import DeepDiff
 from Products.ERP5Type import Permissions
 from Products.ERP5Type.Globals import InitializeClass
 from Products.ERP5Type.Tool.BaseTool import BaseTool
@@ -134,7 +135,7 @@ class PortalPatch:
     new_value_dict = self.removePropertyList(self.new_value, export=True)
 
     # Get the DeepDiff in tree format.
-    tree_diff = deepdiff.DeepDiff(old_value_dict,
+    tree_diff = DeepDiff(old_value_dict,
                          new_value_dict,
                          view='tree')
     diff_tree_list = []

product/ERP5Type/patches/diff.py

+# -*- coding: utf-8 -*-
+##############################################################################
+#
+# Copyright (c) 2018 Nexedi SA and Contributors. All Rights Reserved.
+#
+# WARNING: This program as such is intended to be used by professional
+# programmers who take the whole responsibility of assessing all potential
+# consequences resulting from its eventual inadequacies and bugs
+# End users who are looking for a ready-to-use solution with commercial
+# guarantees and support are strongly adviced to contract a Free Software
+# Service Company
+#
+# This program is Free Software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+##############################################################################
+
+import warnings
+from collections import Mapping
+from collections import Iterable
+try:
+  from deepdiff import DeepDiff
+except ImportError:
+  DeepDiff = None
+  warnings.warn("Please install deepdiff, it is needed by json_representable mixin",
+                DeprecationWarning)
+try:
+  from deepdiff.helper import strings, numbers
+except ImportError:
+  strings = None
+  numbers = None
+  warnings.warn("Please install deepdiff, it is needed by json_representable mixin",
+                DeprecationWarning)
+
+
+def DeepDiff__diff_iterable(self, level, parents_ids=frozenset({})):
+    """Difference of iterables"""
+    level.t1 = str(level.t1)
+    level.t2 = str(level.t2)
+    self._DeepDiff__diff_str(level)
+
+def DeepDiff__diff(self, level, parents_ids=frozenset({})):
+    """The main diff method"""
+    if level.t1 is level.t2:
+        return
+    if self._DeepDiff__skip_this(level):
+        return
+
+    if type(level.t1) != type(level.t2):
+        self._DeepDiff__diff_types(level)
+
+    elif isinstance(level.t1, strings):
+        self._DeepDiff__diff_str(level)
+
+    elif isinstance(level.t1, numbers):
+        self._DeepDiff__diff_numbers(level)
+
+    elif isinstance(level.t1, Mapping):
+        self._DeepDiff__diff_dict(level, parents_ids)
+
+    elif isinstance(level.t1, tuple):
+        self._DeepDiff__diff_str(level)
+
+    elif isinstance(level.t1, (set, frozenset)):
+        self._DeepDiff__diff_set(level)
+
+    elif isinstance(level.t1, Iterable):
+        if self.ignore_order:
+            self._DeepDiff__diff_iterable_with_contenthash(level)
+        else:
+            self._DeepDiff__diff_iterable(level, parents_ids)
+
+    else:
+        self._DeepDiff__diff_obj(level, parents_ids)
+
+    return
+
+# Monkey patch the functions for DeepDiff class.
+# This patch fixes the requirement of diffing the iterables which by default
+# was too complicated in DeepDiff(doing recursive diff inside the iterables).
+# Rather than doing that, now we treat the iterables as string and calculate
+# the diff accordingly
+DeepDiff._DeepDiff__diff_iterable = DeepDiff__diff_iterable
+DeepDiff._DeepDiff__diff = DeepDiff__diff