Make `@view_paths` on the lookup context mostly read-only

The `with_fallbacks` method will temporarily mutate the lookup context
instance, but nobody can call the setter, and we don't have to do a push
/ pop dance.

1 files changed, 7 insertions, 3 deletions

diff --git a/actionview/test/template/lookup_context_test.rb b/actionview/test/template/lookup_context_test.rb
index 02b5d48e5a..0894925c9f 100644
--- a/actionview/test/template/lookup_context_test.rb
+++ b/actionview/test/template/lookup_context_test.rb
@@ -5,10 +5,14 @@ require "abstract_controller/rendering"
 
 class LookupContextTest < ActiveSupport::TestCase
   def setup
-    @lookup_context = ActionView::LookupContext.new(FIXTURE_LOAD_PATH, {})
+    @lookup_context = build_lookup_context(FIXTURE_LOAD_PATH, {})
     ActionView::LookupContext::DetailsKey.clear
   end
 
+  def build_lookup_context(paths, details)
+    ActionView::LookupContext.new(paths, details)
+  end
+
   def teardown
     I18n.locale = :en
   end
@@ -156,7 +160,7 @@ class LookupContextTest < ActiveSupport::TestCase
   end
 
   test "gives the key forward to the resolver, so it can be used as cache key" do
-    @lookup_context.view_paths = ActionView::FixtureResolver.new("test/_foo.erb" => "Foo")
+    @lookup_context = build_lookup_context(ActionView::FixtureResolver.new("test/_foo.erb" => "Foo"), {})
     template = @lookup_context.find("foo", %w(test), true)
     assert_equal "Foo", template.source
 
@@ -185,7 +189,7 @@ class LookupContextTest < ActiveSupport::TestCase
   end
 
   test "can disable the cache on demand" do
-    @lookup_context.view_paths = ActionView::FixtureResolver.new("test/_foo.erb" => "Foo")
+    @lookup_context = build_lookup_context(ActionView::FixtureResolver.new("test/_foo.erb" => "Foo"), {})
     old_template = @lookup_context.find("foo", %w(test), true)
 
     template = @lookup_context.find("foo", %w(test), true)