Merge pull request #9156 from mvdbeek/restore_optional_param_none

[19.05] Cast to None for optional params if not comparing strings

lib/galaxy/tools/wrappers.py

@@ -83,8 +83,11 @@ class InputValueWrapper(ToolParameterValueWrapper):
         if self.input.type == 'boolean' and isinstance(other, string_types):
             return str(self)
         # For backward compatibility, allow `$wrapper != ""` for optional non-text param
-        if self.input.optional and self.value is None and self.input.type != 'boolean':
-            return str(self)
+        if self.input.optional and self.value is None:
+            if isinstance(other, string_types):
+                return str(self)
+            else:
+                return None
         cast = {
             'text': str,
             'integer': int,

test/unit/tools/test_wrappers.py

@@ -161,6 +161,7 @@ def test_input_value_wrapper_comparison_optional(tool):
     wrapper = valuewrapper(tool, None, 'integer', optional=True)
     assert wrapper != 1
     assert str(wrapper) == ""
+    assert wrapper == None  # noqa: E711
     wrapper = valuewrapper(tool, None, "boolean")
     assert bool(wrapper) is False, wrapper
     assert str(wrapper) == 'falsevalue'