google · dbieber · Apr 16, 2022 · Apr 16, 2022 · Apr 16, 2022 · Apr 16, 2022
diff --git a/fire/core.py b/fire/core.py
@@ -164,7 +164,8 @@ def Fire(component=None, command=None, name=None, serialize=None):
    raise FireExit(0, component_trace)

  # The command succeeded normally; print the result.
-  _PrintResult(component_trace, verbose=component_trace.verbose, serialize=serialize)
+  _PrintResult(
+      component_trace, verbose=component_trace.verbose, serialize=serialize)
  result = component_trace.GetResult()
  return result

@@ -247,11 +248,12 @@ def _PrintResult(component_trace, verbose=False, serialize=None):
  # and move serialization to its own module.
  result = component_trace.GetResult()

-  # Allow users to modify the return value of the component and provide 
+  # Allow users to modify the return value of the component and provide
  # custom formatting.
  if serialize:
    if not callable(serialize):
-      raise FireError("serialize argument {} must be empty or callable.".format(serialize))
+      raise FireError(
+          'The argument `serialize` must be empty or callable:', serialize)
    result = serialize(result)

  if value_types.HasCustomStr(result):

diff --git a/fire/core_test.py b/fire/core_test.py
@@ -199,21 +199,22 @@ def serialize(x):
      if isinstance(x, list):
        return ', '.join(str(xi) for xi in x)
      if isinstance(x, dict):
-        return ', '.join('{}={!r}'.format(k, v) for k, v in x.items())
+        return ', '.join('{}={!r}'.format(k, v) for k, v in sorted(x.items()))
      if x == 'special':
        return ['SURPRISE!!', "I'm a list!"]
      return x

    ident = lambda x: x
-    
+
    with self.assertOutputMatches(stdout='a, b', stderr=None):
-      result = core.Fire(ident, command=['[a,b]'], serialize=serialize)
+      _ = core.Fire(ident, command=['[a,b]'], serialize=serialize)
    with self.assertOutputMatches(stdout='a=5, b=6', stderr=None):
-      result = core.Fire(ident, command=['{a:5,b:6}'], serialize=serialize)
+      _ = core.Fire(ident, command=['{a:5,b:6}'], serialize=serialize)
    with self.assertOutputMatches(stdout='asdf', stderr=None):
-      result = core.Fire(ident, command=['asdf'], serialize=serialize)
-    with self.assertOutputMatches(stdout="SURPRISE!!\nI'm a list!\n", stderr=None):
-      result = core.Fire(ident, command=['special'], serialize=serialize)
+      _ = core.Fire(ident, command=['asdf'], serialize=serialize)
+    with self.assertOutputMatches(
+        stdout="SURPRISE!!\nI'm a list!\n", stderr=None):
+      _ = core.Fire(ident, command=['special'], serialize=serialize)
    with self.assertRaises(core.FireError):
      core.Fire(ident, command=['asdf'], serialize=55)