Merge branch 'fix-webmock-adapter-enable-disable-issue' into 'master'

Fix WebMock adapter so that it gets disabled when WebMock gets disabled

See merge request os85/httpx!247

integration_tests/webmock_test.rb

@@ -204,6 +204,16 @@ class WebmockTest < Minitest::Test
     WebMock.disable_net_connect!
   end
 
+  def test_webmock_disable_after_enable
+    WebMock.disable!
+
+    # WebMock is disabled so this will make a real http request
+    http_request(:get, "http://#{httpbin}")
+
+    # WebMock is disabled so it should not have registered the request
+    assert_not_requested(:get, "http://#{httpbin}")
+  end
+
   private
 
   def assert_raise_with_message(e, message, &block)

lib/httpx/adapters/webmock.rb

@@ -122,7 +122,7 @@ module WebMock
 
       class << self
         def enable!
-          @original_session = HTTPX::Session
+          @original_session ||= HTTPX::Session
 
           webmock_session = HTTPX.plugin(Plugin)