From 9d1cccd14d409f1464abe345ce8601c08c6a092a Mon Sep 17 00:00:00 2001
From: mvdbeek <m.vandenbeek@gmail.com>
Date: Fri, 20 Dec 2019 12:17:46 +0100
Subject: [PATCH] Cast to None for optional params if not comparing strings

Proposed by @nsroanzo in https://github.com/galaxyproject/galaxy/pull/9149#discussion_r360225247
---
 lib/galaxy/tools/wrappers.py     | 7 +++++--
 test/unit/tools/test_wrappers.py | 1 +
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/galaxy/tools/wrappers.py b/lib/galaxy/tools/wrappers.py
index 89776480080..c49702fe307 100644
--- a/lib/galaxy/tools/wrappers.py
+++ b/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,
diff --git a/test/unit/tools/test_wrappers.py b/test/unit/tools/test_wrappers.py
index b1567be682c..5acea546dbd 100644
--- a/test/unit/tools/test_wrappers.py
+++ b/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'