Enable caching in development, but discard on each request.

This is the same strategy as followed by ActionView.

This prevents multiple recompiles during the same request

Closes: #345

CHANGELOG.md

@@ -1,5 +1,9 @@
 # master
 
+* Cache components per-request in development, preventing unnecessary recompilation during a single request.
+
+    *Felipe Sateler*
+
 # 2.8.0
 
 * Add `before_render`, deprecating `before_render_check`.

README.md

@@ -778,10 +778,10 @@ ViewComponent is built by:
 |@blakewilliams|@seanpdoyle|@tclem|@nashby|@jaredcwhite|
 |Boston, MA|New York, NY|San Francisco, CA|Minsk|Portland, OR|
 
-|<img src="https://avatars.githubusercontent.com/simonrand?s=256" alt="simonrand" width="128" />|<img src="https://avatars.githubusercontent.com/fugufish?s=256" alt="fugufish" width="128" />|<img src="https://avatars.githubusercontent.com/cover?s=256" alt="cover" width="128" />|<img src="https://avatars.githubusercontent.com/franks921?s=256" alt="franks921" width="128" />|
-|:---:|:---:|:---:|:---:|
-|@simonrand|@fugufish|@cover|@franks921|
-|Dublin, Ireland|Salt Lake City, Utah|Barcelona|South Africa|
+|<img src="https://avatars.githubusercontent.com/simonrand?s=256" alt="simonrand" width="128" />|<img src="https://avatars.githubusercontent.com/fugufish?s=256" alt="fugufish" width="128" />|<img src="https://avatars.githubusercontent.com/cover?s=256" alt="cover" width="128" />|<img src="https://avatars.githubusercontent.com/franks921?s=256" alt="franks921" width="128" />|<img src="https://avatars.githubusercontent.com/fsateler?s=256" alt="fsateler" width="128" />|
+|:---:|:---:|:---:|:---:|:---:|
+|@simonrand|@fugufish|@cover|@franks921|fsateler|
+|Dublin, Ireland|Salt Lake City, Utah|Barcelona|South Africa|Chile|
 
 ## License
 

coverage/coverage.txt

@@ -3,8 +3,8 @@ Incomplete test coverage
 --------------------------------------------------------------------------------
 
 /app/controllers/view_components_controller.rb: 97.22% (missed: 49)
-/lib/view_component/base.rb: 97.75% (missed: 169,254,282,332)
+/lib/view_component/base.rb: 97.78% (missed: 170,253,281,331)
 /lib/view_component/preview.rb: 92.31% (missed: 32,42,78)
 /lib/view_component/render_to_string_monkey_patch.rb: 83.33% (missed: 9)
-/lib/view_component/test_helpers.rb: 95.45% (missed: 17)
-/test/view_component/integration_test.rb: 97.16% (missed: 14,15,16,18,20)
+/lib/view_component/test_helpers.rb: 95.65% (missed: 17)
+/test/view_component/integration_test.rb: 97.55% (missed: 14,15,16,18,20)

lib/view_component/base.rb

@@ -3,6 +3,7 @@
 require "action_view"
 require "active_support/configurable"
 require "view_component/collection"
+require "view_component/compile_cache"
 require "view_component/previewable"
 
 module ViewComponent
@@ -192,9 +193,7 @@ module ViewComponent
       end
 
       def compiled?
-        @compiled ||= false
-
-        @compiled && ActionView::Base.cache_template_loading
+        CompileCache.compiled?(self)
       end
 
       # Compile templates to instance methods, assuming they haven't been compiled already.
@@ -270,7 +269,7 @@ module ViewComponent
           RUBY
         end
 
-        @compiled = true
+        CompileCache.register self
       end
 
       # we'll eventually want to update this to support other types

lib/view_component/compile_cache.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module ViewComponent
+  # Keeps track of which templates have already been compiled
+  # This is not part of the public API
+  module CompileCache
+    mattr_accessor :cache, instance_reader: false, instance_accessor: false do
+      Set.new
+    end
+    module_function
+
+    def register(klass)
+      cache << klass
+    end
+
+    def compiled?(klass)
+      cache.include? klass
+    end
+
+    def invalidate!
+      cache.clear
+    end
+  end
+end

lib/view_component/engine.rb

@@ -69,6 +69,10 @@ module ViewComponent
           get "#{options.preview_route}/*path", to: "view_components#previews", as: :preview_view_component, internal: true
         end
       end
+
+      app.executor.to_run :before do
+        CompileCache.invalidate! unless ActionView::Base.cache_template_loading
+      end
     end
   end
 end

test/test_helper.rb

@@ -30,3 +30,14 @@ def with_preview_route(new_value)
   Rails.application.config.view_component.preview_route = old_value
   app.reloader.reload!
 end
+
+def modify_file(file, content)
+  filename = Rails.root.join(file)
+  old_content = File.read(filename)
+  begin
+    File.open(filename, "wb+") { |f| f.write(content) }
+    yield
+  ensure
+    File.open(filename, "wb+") { |f| f.write(old_content) }
+  end
+end

test/view_component/integration_test.rb

@@ -38,6 +38,49 @@ class IntegrationTest < ActionDispatch::IntegrationTest
     assert_includes inline_response, baseline_response
   end
 
+  test "template changes are not reflected on new request when cache_template_loading is true" do
+    # cache_template_loading is set to true on the initializer
+
+    get "/controller_inline"
+    assert_select("div", "bar")
+    assert_response :success
+
+    modify_file "app/components/controller_inline_component.html.erb", "<div>Goodbye world!</div>" do
+      get "/controller_inline"
+      assert_select("div", "bar")
+      assert_response :success
+    end
+
+    get "/controller_inline"
+    assert_select("div", "bar")
+    assert_response :success
+  end
+
+  test "template changes are reflected on new request when cache_template_loading is false" do
+    begin
+      old_cache = ViewComponent::CompileCache.cache
+      ViewComponent::CompileCache.cache = Set.new
+      ActionView::Base.cache_template_loading = false
+
+      get "/controller_inline"
+      assert_select("div", "bar")
+      assert_response :success
+
+      modify_file "app/components/controller_inline_component.html.erb", "<div>Goodbye world!</div>" do
+        get "/controller_inline"
+        assert_select("div", "Goodbye world!")
+        assert_response :success
+      end
+
+      get "/controller_inline"
+      assert_select("div", "bar")
+      assert_response :success
+    ensure
+      ActionView::Base.cache_template_loading = true
+      ViewComponent::CompileCache.cache = old_cache
+    end
+  end
+
   test "rendering component in a controller using #render_to_string" do
     get "/controller_inline_baseline"
 

test/view_component/view_component_test.rb

@@ -275,9 +275,7 @@ class ViewComponentTest < ViewComponent::TestCase
     assert_text(%r{http://assets.example.com/assets/application-\w+.css})
   end
 
-  def test_template_changes_are_not_reflected_in_production
-    old_value = ActionView::Base.cache_template_loading
-    ActionView::Base.cache_template_loading = true
+  def test_template_changes_are_not_reflected_if_cache_is_not_cleared
 
     render_inline(MyComponent.new)
 
@@ -290,29 +288,6 @@ class ViewComponentTest < ViewComponent::TestCase
     end
 
     render_inline(MyComponent.new)
-
-    ActionView::Base.cache_template_loading = old_value
-  end
-
-  def test_template_changes_are_reflected_outside_production
-    old_value = ActionView::Base.cache_template_loading
-    ActionView::Base.cache_template_loading = false
-
-    render_inline(MyComponent.new)
-
-    assert_text("hello,world!")
-
-    modify_file "app/components/my_component.html.erb", "<div>Goodbye world!</div>" do
-      render_inline(MyComponent.new)
-
-      assert_text("Goodbye world!")
-    end
-
-    render_inline(MyComponent.new)
-
-    assert_text("hello,world!")
-
-    ActionView::Base.cache_template_loading = old_value
   end
 
   def test_that_it_has_a_version_number
@@ -548,17 +523,4 @@ class ViewComponentTest < ViewComponent::TestCase
 
     assert_match(/MissingDefaultCollectionParameterComponent initializer must accept `missing_default_collection_parameter` collection parameter/, exception.message)
   end
-
-  private
-
-  def modify_file(file, content)
-    filename = Rails.root.join(file)
-    old_content = File.read(filename)
-    begin
-      File.open(filename, "wb+") { |f| f.write(content) }
-      yield
-    ensure
-      File.open(filename, "wb+") { |f| f.write(old_content) }
-    end
-  end
 end