Migrate strip_trailing_whitespace to component-local-config

Author: boardfish

lib/view_component/base.rb

@@ -46,10 +46,6 @@ def config
     # For Content Security Policy nonces
     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
-
     attr_accessor :__vc_original_view_context
 
     # Components render in their own view context. Helpers and other functionality
@@ -611,14 +607,28 @@ def with_collection_parameter(parameter)
       #
       # @param value [Boolean] Whether to strip newlines.
       def strip_trailing_whitespace(value = true)
-        self.__vc_strip_trailing_whitespace = value
+        ViewComponent::Deprecation.deprecation_warning(
+          "strip_trailing_whitespace",
+          %(
+            Use the new component-local configuration option instead:
+
+            ```rb
+            class #{self.class.name} < ViewComponent::Base
+              configure do |config|
+                config.strip_trailing_whitespace = #{value}
+              end
+            end
+            ```
+          )
+        )
+        configuration.strip_trailing_whitespace = value
       end
 
       # Whether trailing whitespace will be stripped before compilation.
       #
       # @return [Boolean]
       def strip_trailing_whitespace?
-        __vc_strip_trailing_whitespace
+        configuration.strip_trailing_whitespace
       end
 
       # Ensure the component initializer accepts the

lib/view_component/component_local_config.rb

@@ -4,7 +4,9 @@ module ViewComponent
   module ComponentLocalConfig
     class Configuration
       def initialize
-        @config = ActiveSupport::OrderedOptions[]
+        @config = ActiveSupport::OrderedOptions[
+          strip_trailing_whitespace: false
+        ]
       end
 
       delegate_missing_to :@config
@@ -45,4 +47,4 @@ def configure(&block)
       end
     end
   end
-end
+end