view component lookup_context cache in class attribute, support rails 6+

Author: ermolaev

lib/view_component/base.rb

@@ -24,6 +24,9 @@ class Base < ActionView::Base
     class_attribute :slots
     self.slots = {}
 
+    class_attribute :vc_lookup_context
+    self.vc_lookup_context = ActionView::LookupContext.new(ActionView::PathSet.new([Rails.root.join("app/components")]), {}, [])
+
     # Entrypoint for rendering components.
     #
     # view_context: ActionView context from calling view
@@ -52,9 +55,7 @@ def render_in(view_context, &block)
       self.class.compile(raise_errors: true)
 
       @view_context = view_context
-      @lookup_context ||= view_context.lookup_context.tap do |c|
-        c.view_paths.unshift(Rails.root.join("app/components"))
-      end
+      @lookup_context = vc_lookup_context
 
       # required for path helpers in older Rails versions
       @view_renderer ||= view_context.view_renderer
@@ -66,7 +67,7 @@ def render_in(view_context, &block)
       @virtual_path ||= virtual_path
 
       # For template variants (+phone, +desktop, etc.)
-      @variant ||= @lookup_context.variants.first
+      @variant ||= view_context.lookup_context.variants.first
 
       # For caching, such as #cache_if
       @current_template = nil unless defined?(@current_template)

test/view_component/view_component_test.rb

@@ -672,11 +672,14 @@ def test_inherited_inline_component_inherits_inline_method
     assert_selector("input[type='text'][name='name']")
   end
 
-  def test_cache_digest
-    cache_key = render_inline(CacheComponent.new).text
+  if Rails.version.to_f >= 6.0
+    def test_cache_digest
+      cache_key = render_inline(CacheComponent.new).text
 
-    assert_includes cache_key, "cache-key"
-    assert_match(/\w{32}/, cache_key.sub("cache-key", ""))
+      assert_includes cache_key, "cache-key"
+
+      assert_match(/\w{32}/, cache_key.sub("cache-key", ""))
+    end
   end
 
 end