Add a step attribute when a numeric field is integer only

lib/simple_form/inputs/numeric_input.rb

@@ -33,8 +33,9 @@ module SimpleForm
 
         options = num_validator.__send__(:options)
 
-        input_options[:min] ||= options[:greater_than_or_equal_to]
-        input_options[:max] ||= options[:less_than_or_equal_to]
+        input_options[:min]  ||= options[:greater_than_or_equal_to]
+        input_options[:max]  ||= options[:less_than_or_equal_to]
+        input_options[:step] ||= options[:only_integer] && 1
       end
     end
   end

test/inputs_test.rb

@@ -64,6 +64,11 @@ class InputTest < ActionView::TestCase
     assert_select 'input[max=99]'
   end
 
+  test 'input should get the step attr from a numericality validation' do
+    with_input_for @validating_user, :age, :integer
+    assert_select 'input[step=1]'
+  end
+
   test 'input should generate a float text field for float attributes ' do
     with_input_for @user, :age, :float
     assert_select 'input[type=number].float#user_age'

test/support/models.rb

@@ -118,5 +118,8 @@ class ValidatingUser < User
   include ActiveModel::Validations
   validates :name, :presence => true
   validates :company, :presence => true
-  validates_numericality_of :age, :greater_than_or_equal_to => 18, :less_than_or_equal_to => 99
+  validates_numericality_of :age,
+    :greater_than_or_equal_to => 18,
+    :less_than_or_equal_to => 99,
+    :only_integer => true
 end