Wrapping up t-prefix fix (#89)

* Fix t prefixes not being assigned properly

This fixes a change I made to our t-prefixes that broke things: overriding `ActionView::Base#capture` meant that we'd fire on helper calls too — and extract from their block location.

Note: we're leveraging Rails 6.1+'s `@current_template.virtual_path` to avoid needing to muck with block source_locations or view_paths,
Rails has already figured that out for us.

* Freeze two "." string literals

`t` might be called often on a page and in a nested loop these needless String allocations could add up.
Since they're so easy to fix, let's do it.

lib/nice_partials.rb

@@ -3,11 +3,6 @@
 require_relative "nice_partials/version"
 
 module NicePartials
-  def self.locale_prefix_from(lookup_context, block)
-    partial_location = block.source_location.first.dup
-    lookup_context.view_paths.each { partial_location.delete_prefix!(_1.path)&.delete_prefix!("/") }
-    partial_location.split('.').first.gsub('/_', '/').gsub('/', '.')
-  end
 end
 
 ActiveSupport.on_load :action_view do

lib/nice_partials/monkey_patch.rb

@@ -1,28 +1,41 @@
+# frozen_string_literal: true
+
 # Monkey patch required to make `t` work as expected. Is this evil?
 # TODO Do we need to monkey patch other types of renderers as well?
 module NicePartials::RenderingWithLocalePrefix
-  ActionView::Base.prepend self
+  module BaseIntegration
+    ::ActionView::Base.prepend self
 
-  def capture(*, &block)
-    with_nice_partials_t_prefix(lookup_context, block) { super }
-  end
+    def t(key, options = {})
+      if (template = @_nice_partials_translate_template) && key&.start_with?(".")
+        key = "#{virtual_path_translate_key_prefix(template.virtual_path)}#{key}"
+      end
+
+      super(key, **options)
+    end
 
-  def t(key, options = {})
-    if (prefix = @_nice_partials_t_prefix) && key&.start_with?(".")
-      key = "#{prefix}#{key}"
+    def with_nice_partials_t_prefix(block)
+      old_nice_partials_translate_template = @_nice_partials_translate_template
+      @_nice_partials_translate_template = block ? @current_template : nil
+      yield
+    ensure
+      @_nice_partials_translate_template = old_nice_partials_translate_template
     end
 
-    super(key, **options)
+    private
+
+    def virtual_path_translate_key_prefix(virtual_path)
+      @_scope_key_by_partial_cache ||= {} # Reuses Rails' existing `t` cache.
+      @_scope_key_by_partial_cache[virtual_path] ||= virtual_path.gsub(%r{/_?}, ".")
+    end
   end
 
-  private
+  module PartialRendererIntegration
+    ActionView::PartialRenderer.prepend self
 
-  def with_nice_partials_t_prefix(lookup_context, block)
-    _nice_partials_t_prefix = @_nice_partials_t_prefix
-    @_nice_partials_t_prefix = block ? NicePartials.locale_prefix_from(lookup_context, block) : nil
-    yield
-  ensure
-    @_nice_partials_t_prefix = _nice_partials_t_prefix
+    def render(partial, view, block)
+      view.with_nice_partials_t_prefix(block) { super }
+    end
   end
 end
 

test/fixtures/translations/_nice_partials_translated.html.erb

@@ -1,3 +1,3 @@
-<%= render("basic") do |partial| %>
-  <%= partial.message.t ".message" %>
+<%= render "basic" do %>
+  <% _1.message.t ".message" %>
 <% end %>

test/fixtures/translations/_nice_partials_translated_nested.html.erb

@@ -0,0 +1,6 @@
+<%= render "basic" do %>
+  <% _1.message render("translations/translated") %>
+  <% _1.message do %>
+    <%= render "translations/translated" %>
+  <% end %>
+<% end %>

test/renderer/translation_test.rb

@@ -34,6 +34,12 @@ class Renderer::TranslationTest < NicePartials::Test
     assert_text "nice_partials"
   end
 
+  test "translations nested" do
+    render "translations/nice_partials_translated_nested"
+
+    assert_text "message\n    message\n"
+  end
+
   test "translations key lookup handles special characters" do
     render "translations/special_nice_partials_translated"