Enable components to use @request and request methods/ivars (#2135)

* Enable components to use `@request` and `request` methods/ivars

This replaces internal uses of `request` with `__vc_request` so any
component that uses a request method or ivar will continue to work.

* Update lib/view_component/base.rb

* add test case

* add changelog, fix test case

* fix newline

---------

Co-authored-by: Blake Williams <blake@blakewilliams.me>

docs/CHANGELOG.md

@@ -10,6 +10,10 @@ nav_order: 5
 
 ## main
 
+* Enable components to use `@request` and `request` methods/ivars.
+
+    *Blake Williams*
+
 * Fix bug where implicit locales in component filenames threw a `NameError`.
 
     *Chloe Fons*

lib/view_component/base.rb

@@ -109,10 +109,10 @@ def render_in(view_context, &block)
 
       if render?
         rendered_template =
-          if compiler.renders_template_for?(@__vc_variant, request&.format&.to_sym)
-            render_template_for(@__vc_variant, request&.format&.to_sym)
+          if compiler.renders_template_for?(@__vc_variant, __vc_request&.format&.to_sym)
+            render_template_for(@__vc_variant, __vc_request&.format&.to_sym)
           else
-            maybe_escape_html(render_template_for(@__vc_variant, request&.format&.to_sym)) do
+            maybe_escape_html(render_template_for(@__vc_variant, __vc_request&.format&.to_sym)) do
               Kernel.warn("WARNING: The #{self.class} component rendered HTML-unsafe output. The output will be automatically escaped, but you may want to investigate.")
             end
           end.to_s
@@ -286,7 +286,14 @@ def format
     #
     # @return [ActionDispatch::Request]
     def request
-      @request ||= controller.request if controller.respond_to?(:request)
+      __vc_request
+    end
+
+    # Enables consumers to override request/@request
+    #
+    # @private
+    def __vc_request
+      @__vc_request ||= controller.request if controller.respond_to?(:request)
     end
 
     # The content passed to the component instance as a block.
@@ -328,7 +335,7 @@ def content_evaluated?
     end
 
     def maybe_escape_html(text)
-      return text if request && !request.format.html?
+      return text if __vc_request && !__vc_request.format.html?
       return text if text.blank?
 
       if text.html_safe?

test/sandbox/app/components/request_param_component.rb

@@ -0,0 +1,9 @@
+class RequestParamComponent < ViewComponent::Base
+  def initialize(request:)
+    @request = request
+  end
+
+  def call
+    @request
+  end
+end

test/sandbox/test/rendering_test.rb

@@ -1221,4 +1221,10 @@ def test_localised_component
 
     assert_selector("div", text: "salut,monde!")
   end
+
+  def test_request_param
+    render_inline(RequestParamComponent.new(request: "foo"))
+
+    assert_text("foo")
+  end
 end