Revert "Case Insensitivity for id, fixes #785 (#787)"

This reverts commit f576251.

Changelog.md

@@ -5,6 +5,8 @@ suggestions, ideas and improvements to FriendlyId.
 
 ## Unreleased
 
+* Revert "Make `first_by_friendly_id` case insensitive using `downcase`" ([#951](https://github.com/norman/friendly_id/pull/951))
+
 ## 5.4.1 (2020-11-06)
 
 * Fix unexpected `:slug` error on valid, unpersisted model ([#952](https://github.com/norman/friendly_id/pull/952))

lib/friendly_id/finder_methods.rb

@@ -59,7 +59,7 @@ def potential_primary_key?(id)
     end
 
     def first_by_friendly_id(id)
-      find_by(friendly_id_config.query_field => id.downcase)
+      find_by(friendly_id_config.query_field => id)
     end
 
     def raise_not_found_exception(id)

test/finders_test.rb

@@ -26,28 +26,4 @@ def model_class
       assert model_class.existing.find(record.friendly_id)
     end
   end
-
-  test 'should find capitalized records with finders as class methods' do
-    with_instance_of(model_class) do |record|
-      assert model_class.find(record.friendly_id.capitalize)
-    end
-  end
-
-  test 'should find capitalized records with finders on relations' do
-    with_instance_of(model_class) do |record|
-      assert model_class.existing.find(record.friendly_id.capitalize)
-    end
-  end
-
-  test 'should find upcased records with finders as class methods' do
-    with_instance_of(model_class) do |record|
-      assert model_class.find(record.friendly_id.upcase)
-    end
-  end
-
-  test 'should find upcased records with finders on relations' do
-    with_instance_of(model_class) do |record|
-      assert model_class.existing.find(record.friendly_id.upcase)
-    end
-  end
 end