Scrape out monkey patching

http://rspec.info/blog/2013/07/the-plan-for-rspec-3/#zero_monkey_patching_mode

> we do want to encourage people to switch to the new syntax, so we plan to make RSpec 3 print a warning on first usage of any the old syntax methods (should, should_not, should_receive, etc) unless the should syntax has been explicitly enabled. This should nudge folks towards the new syntax while keeping RSpec friendly to new users and will pave the way for the old syntax to be disabled by default in RSpec 4.

> zero-monkey-patching mode for RSpec...  We plan for these config options to become the defaults in RSpec 4.0, so that RSpec 4.0 will have zero monkey patching out of the box.

As for "disabled by default" vs "completely removed" and "default, out
of the box" vs "impossible" I can only say that RSpec 4 was probably planned to
be released earlier, as:

> we'll probably be dropping support for 1.8.7 in RSpec 4

but we've also dropped 1.9, 2.0, 2.1 and 2.2

#2301 (comment)

> In RSpec 4, we plan to extract all monkey patching from RSpec and move it into a separate gem, so that monkey patching is opt-in instead of opt-out and users have to explicitly install and load a gem to get it.

`rspec-should` (or `rspec-monkey` as it's also about exposing example
group DSL in the top-level/Module?) will be released later.

Those using the monkey-patched `should` syntax are not encouraged to
update to RSpec 4 until this gem is extracted.

Those using the globally-exposed DSL are encouraged to use
`RSpec.describe`/`RSpec.shared_examples_for` instead.

Author: pirj

Changelog.md

@@ -3,6 +3,7 @@
 Breaking Changes:
 
 * Ruby < 2.3 is no longer supported. (Phil Pirozhkov, #2787)
+* Remove monkey-patching syntax. (Phil Pirozhkov, #2803)
 
 Enhancements:
 

features/configuration/enable_global_dsl.feature

@@ -1,4 +1,3 @@
-@oneliner-should
 Feature: One-liner syntax
 
   RSpec supports a one-liner syntax for setting an expectation on the
@@ -14,9 +13,7 @@ Feature: One-liner syntax
     * `is_expected` is defined simply as `expect(subject)` and is designed for
       when you are using rspec-expectations with its newer expect-based syntax.
     * `should` was designed back when rspec-expectations only had a should-based
-      syntax. However, it continues to be available and work even if the
-      `:should` syntax is disabled (since that merely removes `Object#should`
-      but this is `RSpec::Core::ExampleGroup#should`).
+      syntax.
 
   Notes:
 
@@ -29,11 +26,6 @@ Feature: One-liner syntax
       """ruby
       RSpec.describe Array do
         describe "when first created" do
-          # Rather than:
-          # it "should be empty" do
-          #   subject.should be_empty
-          # end
-
           it { should be_empty }
           # or
           it { is_expected.to be_empty }

features/configuration/zero_monkey_patching_mode.feature

@@ -1,29 +1,10 @@
 if defined?(Cucumber)
   require 'shellwords'
-  Before('~@allow-should-syntax', '~@with-clean-spec-opts') do
+  Before('~@with-clean-spec-opts') do
     set_environment_variable('SPEC_OPTS', "-r#{Shellwords.escape(__FILE__)}")
   end
-
-  Before('@oneliner-should') do
-    set_environment_variable('ALLOW_ONELINER_SHOULD', 'true')
-  end
 else
   if ENV['REMOVE_OTHER_RSPEC_LIBS_FROM_LOAD_PATH']
     $LOAD_PATH.reject! { |x| /rspec-mocks/ === x || /rspec-expectations/ === x }
   end
-
-  module DisallowOneLinerShould
-    def should(*)
-      raise "one-liner should is not allowed"
-    end
-
-    def should_not(*)
-      raise "one-liner should_not is not allowed"
-    end
-  end
-
-  RSpec.configure do |rspec|
-    rspec.disable_monkey_patching!
-    rspec.include DisallowOneLinerShould unless ENV['ALLOW_ONELINER_SHOULD']
-  end
 end

features/subject/one_liner_syntax.feature

@@ -178,7 +178,4 @@ def self.const_missing(name)
     require MODULES_TO_AUTOLOAD.fetch(name) { return super }
     ::RSpec.const_get(name)
   end
-
-  Core::DSL.expose_globally!
-  Core::SharedExampleGroup::TopLevelDSL.expose_globally!
 end

features/support/require_expect_syntax_in_aruba_specs.rb

@@ -138,27 +138,6 @@ def default_path=(path)
       # Default: `$stderr`.
       add_setting :error_stream
 
-      # Indicates if the DSL has been exposed off of modules and `main`.
-      # Default: true
-      # @return [Boolean]
-      def expose_dsl_globally?
-        Core::DSL.exposed_globally?
-      end
-
-      # Use this to expose the core RSpec DSL via `Module` and the `main`
-      # object. It will be set automatically but you can override it to
-      # remove the DSL.
-      # Default: true
-      def expose_dsl_globally=(value)
-        if value
-          Core::DSL.expose_globally!
-          Core::SharedExampleGroup::TopLevelDSL.expose_globally!
-        else
-          Core::DSL.remove_globally!
-          Core::SharedExampleGroup::TopLevelDSL.remove_globally!
-        end
-      end
-
       # Determines where deprecation warnings are printed.
       # Defaults to `$stderr`.
       # @return [IO, String] IO or filename to write to
@@ -1179,11 +1158,7 @@ def alias_example_to(name, *args)
       #   RSpec.describe User, :type => :model do
       #   end
       #
-      # @note The defined aliased will also be added to the top level
-      #       (e.g. `main` and from within modules) if
-      #       `expose_dsl_globally` is set to true.
       # @see #alias_example_to
-      # @see #expose_dsl_globally=
       def alias_example_group_to(new_name, *args)
         extra_options = Metadata.build_hash_from(args)
         RSpec::Core::ExampleGroup.define_example_group_method(new_name, extra_options)
@@ -1586,15 +1561,13 @@ def in_project_source_dir_regex
       # @private
       def configure_mock_framework
         RSpec::Core::ExampleGroup.include(mock_framework)
-        conditionally_disable_mocks_monkey_patching
       end
 
       # @private
       def configure_expectation_framework
         expectation_frameworks.each do |framework|
           RSpec::Core::ExampleGroup.include(framework)
         end
-        conditionally_disable_expectations_monkey_patching
       end
 
       # @private
@@ -1804,52 +1777,6 @@ def raise_errors_for_deprecations!
         self.deprecation_stream = Formatters::DeprecationFormatter::RaiseErrorStream.new
       end
 
-      # Enables zero monkey patching mode for RSpec. It removes monkey
-      # patching of the top-level DSL methods (`describe`,
-      # `shared_examples_for`, etc) onto `main` and `Module`, instead
-      # requiring you to prefix these methods with `RSpec.`. It enables
-      # expect-only syntax for rspec-mocks and rspec-expectations. It
-      # simply disables monkey patching on whatever pieces of RSpec
-      # the user is using.
-      #
-      # @note It configures rspec-mocks and rspec-expectations only
-      #   if the user is using those (either explicitly or implicitly
-      #   by not setting `mock_with` or `expect_with` to anything else).
-      #
-      # @note If the user uses this options with `mock_with :mocha`
-      #   (or similiar) they will still have monkey patching active
-      #   in their test environment from mocha.
-      #
-      # @example
-      #
-      #   # It disables all monkey patching.
-      #   RSpec.configure do |config|
-      #     config.disable_monkey_patching!
-      #   end
-      #
-      #   # Is an equivalent to
-      #   RSpec.configure do |config|
-      #     config.expose_dsl_globally = false
-      #
-      #     config.mock_with :rspec do |mocks|
-      #       mocks.syntax = :expect
-      #       mocks.patch_marshal_to_support_partial_doubles = false
-      #     end
-      #
-      #     config.expect_with :rspec do |expectations|
-      #       expectations.syntax = :expect
-      #     end
-      #   end
-      def disable_monkey_patching!
-        self.expose_dsl_globally = false
-        self.disable_monkey_patching = true
-        conditionally_disable_mocks_monkey_patching
-        conditionally_disable_expectations_monkey_patching
-      end
-
-      # @private
-      attr_accessor :disable_monkey_patching
-
       # Defines a callback that can assign derived metadata values.
       #
       # @param filters [Array<Symbol>, Hash] metadata filters that determine
@@ -2260,22 +2187,6 @@ def output_to_tty?(output=output_stream)
         output.respond_to?(:tty?) && output.tty?
       end
 
-      def conditionally_disable_mocks_monkey_patching
-        return unless disable_monkey_patching && rspec_mocks_loaded?
-
-        RSpec::Mocks.configuration.tap do |config|
-          config.syntax = :expect if config.respond_to?(:syntax)
-          config.patch_marshal_to_support_partial_doubles = false
-        end
-      end
-
-      def conditionally_disable_expectations_monkey_patching
-        return unless disable_monkey_patching && rspec_expectations_loaded?
-        return unless RSpec::Expectations.configuration.respond_to?(:syntax=)
-
-        RSpec::Expectations.configuration.syntax = :expect
-      end
-
       def rspec_mocks_loaded?
         defined?(RSpec::Mocks.configuration)
       end