[v4] better handling of splat kwargs and with_collection

Gemfile

@@ -18,6 +18,7 @@ group :development, :test do
   gem "bundler", "~> 2"
   gem "capybara", "~> 3"
   gem "cuprite"
+  gem "dry-initializer", require: true
   gem "erb_lint"
   gem "haml", "~> 6"
   gem "jbuilder", "~> 2"

Gemfile.lock

@@ -119,6 +119,7 @@ GEM
     diff-lcs (1.6.2)
     docile (1.4.1)
     drb (2.2.3)
+    dry-initializer (3.2.0)
     erb (5.0.1)
     erb_lint (0.9.0)
       activesupport
@@ -393,6 +394,7 @@ DEPENDENCIES
   bundler (~> 2)
   capybara (~> 3)
   cuprite
+  dry-initializer
   erb_lint
   haml (~> 6)
   jbuilder (~> 2)

docs/CHANGELOG.md

@@ -14,6 +14,10 @@ nav_order: 6
 
     *Joel Hawksley*
 
+* BREAKING: Support compatibility with `Dry::Initializer`. As a result, `EmptyOrInvalidInitializerError` will no longer be raised.
+
+    *Joel Hawksley*
+
 ## 4.0.0.alpha6
 
 * BREAKING: Remove `config.test_controller` in favor of `vc_test_controller_class` test helper method.

docs/api.md

@@ -466,14 +466,6 @@ It looks like a block was provided after calling `with_content` on COMPONENT, wh
 
 To fix this issue, use either `with_content` or a block.
 
-### `EmptyOrInvalidInitializerError`
-
-The COMPONENT initializer is empty or invalid. It must accept the parameter `PARAMETER` to render it as a collection.
-
-To fix this issue, update the initializer to accept `PARAMETER`.
-
-See [the collections docs](https://viewcomponent.org/guide/collections.html) for more information on rendering collections.
-
 ### `HelpersCalledBeforeRenderError`
 
 `#helpers` can't be used before rendering as it depends on the view context that only exists once a ViewComponent is passed to the Rails render pipeline.

gemfiles/rails_7.1.gemfile

@@ -14,6 +14,7 @@ group :development, :test do
   gem "bundler", "~> 2"
   gem "capybara", "~> 3"
   gem "cuprite"
+  gem "dry-initializer", require: true
   gem "erb_lint"
   gem "haml", "~> 6"
   gem "jbuilder", "~> 2"

gemfiles/rails_7.2.gemfile

@@ -14,6 +14,7 @@ group :development, :test do
   gem "bundler", "~> 2"
   gem "capybara", "~> 3"
   gem "cuprite"
+  gem "dry-initializer", require: true
   gem "erb_lint"
   gem "haml", "~> 6"
   gem "jbuilder", "~> 2"

gemfiles/rails_8.0.gemfile

@@ -14,6 +14,7 @@ group :development, :test do
   gem "bundler", "~> 2"
   gem "capybara", "~> 3"
   gem "cuprite"
+  gem "dry-initializer", require: true
   gem "erb_lint"
   gem "haml", "~> 6"
   gem "jbuilder", "~> 2"

gemfiles/rails_main.gemfile

@@ -15,6 +15,7 @@ group :development, :test do
   gem "bundler", "~> 2"
   gem "capybara", "~> 3"
   gem "cuprite"
+  gem "dry-initializer", require: true
   gem "erb_lint"
   gem "haml", "~> 6"
   gem "jbuilder", "~> 2"

lib/view_component/base.rb

@@ -47,6 +47,7 @@ def config
     end
 
     include ActionView::Helpers
+    include Rails.application.routes.url_helpers if defined?(Rails) && Rails.application
     include ERB::Escape
     include ActiveSupport::CoreExt::ERBUtil
 
@@ -68,8 +69,7 @@ def config
     delegate :content_security_policy_nonce, to: :helpers
 
     # Config option that strips trailing whitespace in templates before compiling them.
-    class_attribute :__vc_strip_trailing_whitespace, instance_accessor: false, instance_predicate: false
-    self.__vc_strip_trailing_whitespace = false # class_attribute:default doesn't work until Rails 5.2
+    class_attribute :__vc_strip_trailing_whitespace, instance_accessor: false, instance_predicate: false, default: false
 
     attr_accessor :__vc_original_view_context
     attr_reader :current_template
@@ -89,6 +89,11 @@ def set_original_view_context(view_context)
 
     using RequestDetails
 
+    # Including `Rails.application.routes.url_helpers` defines an initializer that accepts (...),
+    # so we have to define our own empty initializer to overwrite it.
+    def initialize
+    end
+
     # Entrypoint for rendering components.
     #
     # - `view_context`: ActionView context from calling view
@@ -509,6 +514,11 @@ def with_collection(collection, spacer_component: nil, **args)
         Collection.new(self, collection, spacer_component, **args)
       end
 
+      # @private
+      def __vc_compile(raise_errors: false, force: false)
+        __vc_compiler.compile(raise_errors: raise_errors, force: force)
+      end
+
       # @private
       def inherited(child)
         # Compile so child will inherit compiled `call_*` template methods that
@@ -531,12 +541,6 @@ def render_template_for(requested_details)
           RUBY
         end
 
-        # If Rails application is loaded, add application url_helpers to the component context
-        # we need to check this to use this gem as a dependency
-        if defined?(Rails) && Rails.application && !(child < Rails.application.routes.url_helpers)
-          child.include Rails.application.routes.url_helpers
-        end
-
         # Derive the source location of the component Ruby file from the call stack.
         # We need to ignore `inherited` frames here as they indicate that `inherited`
         # has been re-defined by the consuming application, likely in ApplicationComponent.
@@ -568,11 +572,6 @@ def __vc_ensure_compiled
         __vc_compile unless __vc_compiled?
       end
 
-      # @private
-      def __vc_compile(raise_errors: false, force: false)
-        __vc_compiler.compile(raise_errors: raise_errors, force: force)
-      end
-
       # @private
       def __vc_compiler
         @__vc_compiler ||= Compiler.new(self)
@@ -622,13 +621,6 @@ def __vc_validate_collection_parameter!(validate_default: false)
         return unless parameter
         return if __vc_initialize_parameter_names.include?(parameter) || splatted_keyword_argument_present?
 
-        # If Ruby can't parse the component class, then the initialize
-        # parameters will be empty and ViewComponent will not be able to render
-        # the component.
-        if initialize_parameters.empty?
-          raise EmptyOrInvalidInitializerError.new(name, parameter)
-        end
-
         raise MissingCollectionArgumentError.new(name, parameter)
       end
 
@@ -670,8 +662,7 @@ def __vc_iteration_argument_present?
       private
 
       def splatted_keyword_argument_present?
-        initialize_parameters.flatten.include?(:keyrest) &&
-          !initialize_parameters.include?([:keyrest, :**]) # Un-named splatted keyword args don't count!
+        initialize_parameters.flatten.include?(:keyrest)
       end
 
       def __vc_initialize_parameter_names

lib/view_component/errors.rb

@@ -65,18 +65,6 @@ def initialize(klass_name)
     end
   end
 
-  class EmptyOrInvalidInitializerError < StandardError
-    MESSAGE =
-      "The COMPONENT initializer is empty or invalid. " \
-      "It must accept the parameter `PARAMETER` to render it as a collection.\n\n" \
-      "To fix this issue, update the initializer to accept `PARAMETER`.\n\n" \
-      "See [the collections docs](https://viewcomponent.org/guide/collections.html) for more information on rendering collections."
-
-    def initialize(klass_name, parameter)
-      super(MESSAGE.gsub("COMPONENT", klass_name.to_s).gsub("PARAMETER", parameter.to_s))
-    end
-  end
-
   class MissingCollectionArgumentError < StandardError
     MESSAGE =
       "The initializer for COMPONENT doesn't accept the parameter `PARAMETER`, " \

test/sandbox/app/components/item_component.rb

@@ -0,0 +1,11 @@
+require "dry-initializer"
+
+class ItemComponent < ViewComponent::Base
+  extend Dry::Initializer
+
+  option :item
+
+  erb_template <<~ERB
+    <%= item.name %>
+  ERB
+end

test/sandbox/test/rendering_test.rb

@@ -20,14 +20,36 @@ def test_render_inline_allocations
     MyComponent.__vc_ensure_compiled
 
     with_instrumentation_enabled_option(false) do
-      assert_allocations({"3.5" => 69, "3.4" => 74, "3.3" => 73, "3.2" => 72}) do
+      assert_allocations({"3.5" => 69, "3.4" => 74, "3.3" => 72, "3.2" => 71}) do
         render_inline(MyComponent.new)
       end
     end
 
     assert_selector("div", text: "hello,world!")
   end
 
+  def test_render_collection_inline_allocations
+    # Stabilize compilation status ahead of testing allocations to simulate rendering
+    # performance with compiled component
+    ViewComponent::CompileCache.cache.delete(ProductComponent)
+    ProductComponent.__vc_ensure_compiled
+
+    allocations = {"3.5" => 77, "3.4" => 82, "3.3" => 86, "3.2" => 84}
+
+    products = [Product.new(name: "Radio clock"), Product.new(name: "Mints")]
+    notice = "On sale"
+    # Ensure any one-time allocations are done
+    render_inline(ProductComponent.with_collection(products, notice: notice))
+
+    with_instrumentation_enabled_option(false) do
+      assert_allocations(**allocations) do
+        render_inline(ProductComponent.with_collection(products, notice: notice))
+      end
+    end
+
+    assert_selector("h1", text: "Product", count: 2)
+  end
+
   def test_initialize_super
     render_inline(InitializeSuperComponent.new)
 
@@ -610,25 +632,6 @@ def test_render_collection
     assert_selector("p", text: "Mints counter: 1")
   end
 
-  def test_render_collection_inline_allocations
-    # Stabilize compilation status ahead of testing allocations to simulate rendering
-    # performance with compiled component
-    ViewComponent::CompileCache.cache.delete(ProductComponent)
-    ProductComponent.__vc_ensure_compiled
-
-    allocations = {"3.5" => 79, "3.4" => 84, "3.3" => 110, "3.2" => 108}
-
-    products = [Product.new(name: "Radio clock"), Product.new(name: "Mints")]
-    notice = "On sale"
-    # Ensure any one-time allocations are done
-    render_inline(ProductComponent.with_collection(products, notice: notice))
-
-    assert_allocations(**allocations) do
-      render_inline(ProductComponent.with_collection(products, notice: notice))
-    end
-    assert_selector("h1", text: "Product", count: 2)
-  end
-
   def test_render_collection_custom_collection_parameter_name
     coupons = [Coupon.new(percent_off: 20), Coupon.new(percent_off: 50)]
     render_inline(ProductCouponComponent.with_collection(coupons))
@@ -785,17 +788,6 @@ def test_component_with_invalid_named_parameter_names
     end
   end
 
-  def test_collection_component_with_trailing_comma_attr_reader
-    exception =
-      assert_raises ViewComponent::EmptyOrInvalidInitializerError do
-        render_inline(
-          ProductReaderOopsComponent.with_collection(["foo"])
-        )
-      end
-
-    assert_match(/ProductReaderOopsComponent initializer is empty or invalid/, exception.message)
-  end
-
   def test_renders_component_using_rails_config
     render_inline(RailsConfigComponent.new)
 
@@ -1241,4 +1233,53 @@ def test_custom_base
 
     assert_includes("Hi!", custom_view.render(GreetingComponent.new))
   end
+
+  def test_dry_initializer
+    render_inline(ItemComponent.with_collection([Product.new(name: "Radio clock")]))
+
+    assert_text("Radio clock")
+  end
+
+  class DynamicComponentBase < ViewComponent::Base
+    def setup_component(**attributes)
+      # This method is somewhat contrived, it's intended to mimic features available in the dry-initializer gem.
+      model_name = self.class.name.demodulize.delete_suffix("Component").underscore.to_sym
+      instance_variable_set(:"@#{model_name}", attributes[model_name])
+      define_singleton_method(model_name) { instance_variable_get(:"@#{model_name}") }
+    end
+  end
+
+  class OrderComponent < DynamicComponentBase
+    def initialize(**)
+      setup_component(**)
+    end
+
+    def call
+      "<div data-name='#{order.name}'><h1>#{order.name}</h1></div>".html_safe
+    end
+  end
+
+  class CustomerComponent < DynamicComponentBase
+    def initialize(...)
+      setup_component(...)
+    end
+
+    def call
+      "<div data-name='#{customer.name}'><h1>#{customer.name}</h1></div>".html_safe
+    end
+  end
+
+  def test_supports_components_with_argument_forwarding
+    customers = [Product.new(name: "Taylor"), Product.new(name: "Rowan")]
+    render_inline(CustomerComponent.with_collection(customers))
+    assert_selector("*[data-name='#{customers.first.name}']", text: customers.first.name)
+    assert_selector("*[data-name='#{customers.last.name}']", text: customers.last.name)
+  end
+
+  def test_supports_components_with_unnamed_splatted_arguments
+    orders = [Product.new(name: "O-2024-0004"), Product.new(name: "B-2024-0714")]
+    render_inline(OrderComponent.with_collection(orders))
+    assert_selector("*[data-name='#{orders.first.name}']", text: orders.first.name)
+    assert_selector("*[data-name='#{orders.last.name}']", text: orders.last.name)
+  end
 end