avoid setting non-Strings to nil

lib/strip_attributes.rb

@@ -58,6 +58,8 @@ def self.strip_record(record, options = {})
   end
 
   def self.strip_string(value, options = {})
+    return value unless value.is_a?(String)
+
     allow_empty      = options[:allow_empty]
     collapse_spaces  = options[:collapse_spaces]
     replace_newlines = options[:replace_newlines]

test/strip_attributes_test.rb

@@ -61,6 +61,17 @@ class ReplaceNewLinesAndDuplicateSpaces < Tableless
   strip_attributes replace_newlines: true, collapse_spaces: true
 end
 
+class CoexistWithOtherObjects < Tableless
+  attr_accessor :arr, :hsh, :str
+  strip_attributes
+  def initialize
+    @arr, @hsh, @str = [], {}, "foo "
+  end
+  def attributes
+    {arr: arr, hsh: hsh, str: str}
+  end
+end
+
 class CoexistWithOtherValidations < Tableless
   attribute :number, type: Integer
 
@@ -242,6 +253,14 @@ def test_should_strip_and_allow_empty_always
     assert_equal "",            record.bang
   end
 
+  def test_should_allow_other_empty_objects
+    record = CoexistWithOtherObjects.new
+    record.valid?
+    assert_equal [],    record.arr
+    assert_equal({},    record.hsh)
+    assert_equal "foo", record.str
+  end
+
   def test_should_coexist_with_other_validations
     record = CoexistWithOtherValidations.new
     record.number = 1000.1