Fix accidental extension with Rodauth::ClassMethods

Due to how constant lookup works, defining `ClassMethods` inside the feature
block ended up extending `Rodauth::ClassMethods`, instead of creating a new
`Rodauth::OmniauthBase::ClassMethods` module. This caused issues such as
freezing the Roda app not freezing Rodauth configurations.

We fix this by making the module declaration explicit, and we also need to
explicitly reference it in the `included` hook.

This issue wasn't caught because warnings were disabled in tests. We enable them
and ignore any warnings in gems.

Fixes #31

Gemfile

@@ -13,3 +13,4 @@ end
 
 gem "rake", "~> 13.0"
 gem "matrix" # rack dependency
+gem "warning"

Rakefile

@@ -4,7 +4,7 @@ require "rake/testtask"
 Rake::TestTask.new do |t|
   t.libs << "test"
   t.test_files = FileList["test/**/*_test.rb"]
-  t.warning = false
+  t.warning = true
 end
 
 task default: :test

lib/rodauth/features/omniauth_base.rb

@@ -195,10 +195,12 @@ def handle_omniauth_response(res)
     end
 
     def self.included(auth)
-      auth.extend ClassMethods
+      auth.extend OmniauthBase::ClassMethods
       auth.instance_variable_set(:@omniauth_providers, [])
     end
+  end
 
+  module OmniauthBase
     module ClassMethods
       def inherited(subclass)
         super

test/omniauth_base_test.rb

@@ -497,4 +497,16 @@
     omniauth_login "/auth/developer"
     assert_equal "There was an error logging in with the external provider", page.find("#error_flash").text
   end
+
+  it "supports freezing" do
+    rodauth do
+      enable :omniauth_base
+      omniauth_provider :developer
+    end
+    roda do |r|
+    end
+
+    app.freeze
+    assert app.rodauth.frozen?
+  end
 end

test/test_helper.rb

@@ -1,5 +1,8 @@
 ENV["RACK_ENV"] = "test"
 
+require "warning"
+Gem.path.each { |path| Warning.ignore(//, path) } # ignore warnings in dependencies
+
 require "bundler/setup"
 
 require "minitest/autorun"