Do not assume YAML.unsafe_load is defined in mock specs

It does not appear to be defined with the YAML shipped in Ruby
2.4-2.7.  If not defined, define it to call load.  Fixes tests
when you don't force a psych version beyond the one that ships
with Ruby.  Remove psych from Gemfile so we test the version
that ships with Ruby.

2 files changed, 6 insertions, 2 deletions

diff --git a/Gemfile b/Gemfile
index bfa78b5c..c17dadb5 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,8 +11,6 @@ group :maintenance, optional: true do
   gem "rubocop-packaging", require: false
 end
 
-gem "psych", "~> 4.0"
-
 group :doc do
   gem 'rdoc'
 end
diff --git a/test/spec_mock.rb b/test/spec_mock.rb
index 71001d17..73077fcc 100644
--- a/test/spec_mock.rb
+++ b/test/spec_mock.rb
@@ -3,6 +3,12 @@
 require_relative 'helper'
 require 'yaml'
 
+unless YAML.respond_to?(:unsafe_load)
+  def YAML.unsafe_load(body)
+    load(body)
+  end
+end
+
 app = Rack::Lint.new(lambda { |env|
   req = Rack::Request.new(env)