Support `checked` as a keyword argument in `check_box_tag` and `radio_button_tag`

Currently if you do this:

```ruby
check_box_tag "admin", "1", checked: false
```

It is treated [as truthy](19f9922523/actionview/lib/action_view/helpers/form_tag_helper.rb (L444)), and your checkbox is checked. This can be a bit surprising, particularly because the `FormHelper` version [does support](19f9922523/actionview/lib/action_view/helpers/form_helper.rb (L1285)) a keyword argument.

```ruby
f.check_box "admin", checked: false
```

So this PR updates `check_box_tag` and `radio_button_tag` to support `checked` as a positional or keyword argument, this way you can use the same API in both cases.

Co-authored-by: Jonathan Hefner <jonathan@hefner.pro>

actionview/CHANGELOG.md

@@ -1,3 +1,17 @@
+*   `check_box_tag` and `radio_button_tag` now accept `checked` as a keyword argument
+
+    This is to make the API more consistent with the `FormHelper` variants. You can now provide `checked` as a positional or keyword argument:
+
+    ```erb
+    = check_box_tag "admin", "1", false
+    = check_box_tag "admin", "1", checked: false
+
+    = radio_button_tag 'favorite_color', 'maroon', false
+    = radio_button_tag 'favorite_color', 'maroon', checked: false
+    ```
+
+    *Alex Ghiculescu*
+
 *   Allow passing a class to `dom_id`.
     You no longer need to call `new` when passing a class to `dom_id`.
     This makes `dom_id` behave like `dom_class` in this regard.

actionview/lib/action_view/helpers/form_tag_helper.rb

@@ -422,9 +422,17 @@ module ActionView
         content_tag :textarea, content.to_s.html_safe, { "name" => name, "id" => sanitize_to_id(name) }.update(options)
       end
 
+      ##
+      # :call-seq:
+      #   check_box_tag(name, options = {})
+      #   check_box_tag(name, value, options = {})
+      #   check_box_tag(name, value, checked, options = {})
+      #
       # Creates a check box form input tag.
       #
       # ==== Options
+      # * <tt>:value</tt> - The value of the input. Defaults to <tt>"1"</tt>.
+      # * <tt>:checked</tt> - If set to true, the checkbox will be checked by default.
       # * <tt>:disabled</tt> - If set to true, the user will not be able to use this input.
       # * Any other key creates standard HTML options for the tag.
       #
@@ -443,16 +451,27 @@ module ActionView
       #
       #   check_box_tag 'eula', 'accepted', false, disabled: true
       #   # => <input disabled="disabled" id="eula" name="eula" type="checkbox" value="accepted" />
-      def check_box_tag(name, value = "1", checked = false, options = {})
+      def check_box_tag(name, *args)
+        if args.length >= 4
+          raise ArgumentError, "wrong number of arguments (given #{args.length + 1}, expected 1..4)"
+        end
+        options = args.extract_options!
+        value, checked = args.empty? ? ["1", false] : [*args, false]
         html_options = { "type" => "checkbox", "name" => name, "id" => sanitize_to_id(name), "value" => value }.update(options.stringify_keys)
         html_options["checked"] = "checked" if checked
         tag :input, html_options
       end
 
+      ##
+      # :call-seq:
+      #   radio_button_tag(name, value, options = {})
+      #   radio_button_tag(name, value, checked, options = {})
+      #
       # Creates a radio button; use groups of radio buttons named the same to allow users to
       # select from a group of options.
       #
       # ==== Options
+      # * <tt>:checked</tt> - If set to true, the radio button will be selected by default.
       # * <tt>:disabled</tt> - If set to true, the user will not be able to use this input.
       # * Any other key creates standard HTML options for the tag.
       #
@@ -468,7 +487,12 @@ module ActionView
       #
       #   radio_button_tag 'color', "green", true, class: "color_input"
       #   # => <input checked="checked" class="color_input" id="color_green" name="color" type="radio" value="green" />
-      def radio_button_tag(name, value, checked = false, options = {})
+      def radio_button_tag(name, value, *args)
+        if args.length >= 3
+          raise ArgumentError, "wrong number of arguments (given #{args.length + 2}, expected 2..4)"
+        end
+        options = args.extract_options!
+        checked = args.empty? ? false : args.first
         html_options = { "type" => "radio", "name" => name, "id" => "#{sanitize_to_id(name)}_#{sanitize_to_id(value)}", "value" => value }.update(options.stringify_keys)
         html_options["checked"] = "checked" if checked
         tag :input, html_options

actionview/test/template/form_tag_helper_test.rb

@@ -88,6 +88,36 @@ class FormTagHelperTest < ActionView::TestCase
     assert_dom_equal expected, actual
   end
 
+  def test_check_box_tag_checked_kwarg_true
+    actual = check_box_tag "admin", "yes", checked: true
+    expected = %(<input id="admin" checked="checked" name="admin" type="checkbox" value="yes" />)
+    assert_dom_equal expected, actual
+  end
+
+  def test_check_box_tag_checked_kwarg_false
+    actual = check_box_tag "admin", "1", checked: false
+    expected = %(<input id="admin" name="admin" type="checkbox" value="1" />)
+    assert_dom_equal expected, actual
+  end
+
+  def test_check_box_tag_checked_kwarg_false_and_disabled
+    actual = check_box_tag "admin", "1", checked: false, disabled: true
+    expected = %(<input id="admin" name="admin" type="checkbox" value="1" disabled="disabled" />)
+    assert_dom_equal expected, actual
+  end
+
+  def test_check_box_tag_checked_kwarg_true_value_argument_skipped
+    actual = check_box_tag "admin", checked: true
+    expected = %(<input id="admin" checked="checked" name="admin" type="checkbox" value="1" />)
+    assert_dom_equal expected, actual
+  end
+
+  def test_check_box_tag_value_kwarg
+    actual = check_box_tag "admin", value: "0", checked: true
+    expected = %(<input id="admin" name="admin" type="checkbox" value="0" checked="checked" />)
+    assert_dom_equal expected, actual
+  end
+
   def test_check_box_tag_id_sanitized
     label_elem = root_elem(check_box_tag("project[2][admin]"))
     assert_match VALID_HTML_ID, label_elem["id"]
@@ -374,6 +404,30 @@ class FormTagHelperTest < ActionView::TestCase
     actual = radio_button_tag("ctrlname", "apache2.2")
     expected = %(<input id="ctrlname_apache2.2" name="ctrlname" type="radio" value="apache2.2" />)
     assert_dom_equal expected, actual
+
+    actual = radio_button_tag "people", "david", true
+    expected = %(<input id="people_david" name="people" type="radio" value="david" checked="checked" />)
+    assert_dom_equal expected, actual
+
+    actual = radio_button_tag "people", "david", false
+    expected = %(<input id="people_david" name="people" type="radio" value="david" />)
+    assert_dom_equal expected, actual
+
+    actual = radio_button_tag "people", "david", false, disabled: true
+    expected = %(<input id="people_david" name="people" type="radio" value="david" disabled="disabled" />)
+    assert_dom_equal expected, actual
+
+    actual = radio_button_tag "people", "david", checked: true
+    expected = %(<input id="people_david" name="people" type="radio" value="david" checked="checked" />)
+    assert_dom_equal expected, actual
+
+    actual = radio_button_tag "people", "david", checked: false
+    expected = %(<input id="people_david" name="people" type="radio" value="david" />)
+    assert_dom_equal expected, actual
+
+    actual = radio_button_tag "people", "david", checked: false, disabled: true
+    expected = %(<input id="people_david" name="people" type="radio" value="david" disabled="disabled" />)
+    assert_dom_equal expected, actual
   end
 
   def test_select_tag