Remove monkey patching

features/command_line/exit_status.feature

@@ -71,7 +71,7 @@ Feature: exit status
       require 'rspec/autorun'
       at_exit { exit(0) }
 
-      describe "exit 0 at_exit" do
+      RSpec.describe "exit 0 at_exit" do
         it "does not interfere with rspec's exit code" do
           fail
         end

features/command_line/ruby.feature

@@ -12,7 +12,7 @@ Feature: run with ruby command
       """ruby
       require 'rspec/autorun'
 
-      describe 1 do
+      RSpec.describe 1 do
         it "is < 2" do
           expect(1).to be < 2
         end

features/configuration/enable_global_dsl.feature

@@ -0,0 +1,54 @@
+Feature: Global namespace DSL
+
+  RSpec has a few top-level constructs that allow you to begin describing
+  behaviour:
+
+  * `RSpec.describe`: Define a named context for a group of examples.
+  * `RSpec.shared_examples_for`: Define a set of shared examples that can later be included in an example group.
+  * `RSpec.shared_context`: define some common context (using `before`, `let`, helper methods, etc) that can later be included in an example group.
+
+  Historically, these constructs have been available directly off of the main
+  object, so that you could use these at the start of a file without the
+  `RSpec.` prefix. They have also been available off of any class or module so
+  that you can scope your examples within a particular constant namespace.
+
+  RSpec 3 now provides an option to disable this global monkey patching:
+
+  `config.expose_dsl_globally = false`.
+
+  For backwards compatibility it defaults to true.
+
+  Scenario: by default RSpec allows the DSL to be used globally
+    Given a file named "spec/example_spec.rb" with:
+      """ruby
+      describe "specs here" do
+        it "passes" do
+        end
+      end
+      """
+   When I run `rspec`
+   Then the output should contain "1 example, 0 failures"
+
+  Scenario: when exposing globally is disabled the top level DSL no longer works
+    Given a file named "spec/example_spec.rb" with:
+      """ruby
+      RSpec.configure { |c| c.expose_dsl_globally = false }
+      describe "specs here" do
+        it "passes" do
+        end
+      end
+      """
+   When I run `rspec`
+   Then the output should contain "undefined method `describe'"
+
+  Scenario: regardless of setting
+    Given a file named "spec/example_spec.rb" with:
+      """ruby
+      RSpec.configure { |c| c.expose_dsl_globally = true }
+      RSpec.describe "specs here" do
+        it "passes" do
+        end
+      end
+      """
+   When I run `rspec`
+   Then the output should contain "1 example, 0 failures"

lib/rspec/core.rb

@@ -99,7 +99,12 @@ def self.configuration
 
 WARNING
     end
-    @configuration ||= RSpec::Core::Configuration.new
+    @configuration ||= begin
+                         config = RSpec::Core::Configuration.new
+                         config.expose_dsl_globally = true
+                         config
+                       end
+
   end
 
   # @private

lib/rspec/core/configuration.rb

@@ -102,6 +102,23 @@ def self.add_setting(name, opts={})
       # Default: `$stderr`.
       add_setting :error_stream
 
+      # @macro add_setting
+      # Default: true
+      # 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.
+      add_setting :expose_dsl_globally
+
+      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
+
       # @macro add_setting
       # Default: `$stderr`.
       add_setting :deprecation_stream

lib/rspec/core/dsl.rb

@@ -1,26 +1,66 @@
 module RSpec
+
+  # Defines a named context for one or more examples. The given block
+  # is evaluated in the context of a generated subclass of
+  # {RSpec::Core::ExampleGroup}
+  #
+  # ## Examples:
+  #
+  #     describe "something" do
+  #       it "does something" do
+  #         # example code goes here
+  #       end
+  #     end
+  #
+  # @see ExampleGroup
+  # @see ExampleGroup.describe
+  def self.describe(*args, &example_group_block)
+    RSpec::Core::ExampleGroup.describe(*args, &example_group_block).register
+  end
+
   module Core
-    # Adds the `describe` method to the top-level namespace.
     module DSL
-      # Generates a subclass of {ExampleGroup}
-      #
-      # ## Examples:
-      #
-      #     describe "something" do
-      #       it "does something" do
-      #         # example code goes here
-      #       end
-      #     end
-      #
-      # @see ExampleGroup
-      # @see ExampleGroup.describe
-      def describe(*args, &example_group_block)
-        RSpec::Core::ExampleGroup.describe(*args, &example_group_block).register
+
+      class << self
+        # @private
+        attr_accessor :top_level
+      end
+
+      # @private
+      def self.exposed_globally?
+        @exposed_globally ||= false
+      end
+
+      # Add's the describe method to Module and the top level binding
+      def self.expose_globally!
+        return if exposed_globally?
+
+        to_define = proc do
+          def describe(*args, &block)
+            ::RSpec.describe(*args, &block)
+          end
+        end
+
+        top_level.instance_eval(&to_define)
+        Module.class_exec(&to_define)
+        @exposed_globally = true
+      end
+
+      def self.remove_globally!
+        return unless exposed_globally?
+
+        to_undefine = proc do
+          undef describe
+        end
+
+        top_level.instance_eval(&to_undefine)
+        Module.class_exec(&to_undefine)
+        @exposed_globally = false
       end
+
     end
   end
 end
 
-extend RSpec::Core::DSL
-Module.send(:include, RSpec::Core::DSL)
-
+# cature main without an eval
+::RSpec::Core::DSL.top_level = self

lib/rspec/core/shared_example_group.rb

@@ -41,17 +41,49 @@ def shared_example_groups
       end
 
       module TopLevelDSL
-        def shared_examples(*args, &block)
-          SharedExampleGroup.registry.add_group('main', *args, &block)
+        def self.definitions
+          proc do
+            def shared_examples(*args, &block)
+              SharedExampleGroup.registry.add_group('main', *args, &block)
+            end
+            alias :shared_context      :shared_examples
+            alias :share_examples_for  :shared_examples
+            alias :shared_examples_for :shared_examples
+            def shared_example_groups
+              SharedExampleGroup.registry.shared_example_groups_for('main')
+            end
+          end
         end
 
-        alias_method :shared_context,      :shared_examples
-        alias_method :share_examples_for,  :shared_examples
-        alias_method :shared_examples_for, :shared_examples
+        # @private
+        def self.exposed_globally?
+          @exposed_globally ||= false
+        end
 
-        def shared_example_groups
-          SharedExampleGroup.registry.shared_example_groups_for('main')
+        def self.expose_globally!
+          return if exposed_globally?
+
+          Core::DSL.top_level.instance_eval(&definitions)
+          Module.class_exec(&definitions)
+          @exposed_globally = true
+        end
+
+        def self.remove_globally!
+          return unless exposed_globally?
+
+          to_undefine = proc do
+            undef shared_examples
+            undef shared_context
+            undef share_examples_for
+            undef shared_examples_for
+            undef shared_example_groups
+          end
+
+          Core::DSL.top_level.instance_eval(&to_undefine)
+          Module.class_exec(&to_undefine)
+          @exposed_globally = false
         end
+
       end
 
       def self.registry
@@ -140,7 +172,6 @@ def ensure_block_has_source_location(block, caller_line)
       end
     end
   end
-end
 
-extend RSpec::Core::SharedExampleGroup::TopLevelDSL
-Module.send(:include, RSpec::Core::SharedExampleGroup::TopLevelDSL)
+  instance_eval &Core::SharedExampleGroup::TopLevelDSL.definitions
+end

script/ignores

@@ -72,3 +72,16 @@ lib/rspec/core/example_group.rb:        subclass = Class.new(parent)
 # This happens at file load time.
 lib/rspec/core/formatters/deprecation_formatter.rb:    DeprecationError = Class.new(StandardError)
 
+# This enables / disable monkey patching and only happens on demand
+lib/rspec/core/dsl.rb:        to_undefine = proc do
+lib/rspec/core/dsl.rb:          undef describe
+lib/rspec/core/dsl.rb:        top_level.instance_eval(&to_undefine)
+lib/rspec/core/dsl.rb:        Module.class_exec(&to_undefine)
+lib/rspec/core/shared_example_group.rb:          to_undefine = proc do
+lib/rspec/core/shared_example_group.rb:            undef shared_examples
+lib/rspec/core/shared_example_group.rb:            undef shared_context
+lib/rspec/core/shared_example_group.rb:            undef share_examples_for
+lib/rspec/core/shared_example_group.rb:            undef shared_examples_for
+lib/rspec/core/shared_example_group.rb:            undef shared_example_groups
+lib/rspec/core/shared_example_group.rb:          Core::DSL.top_level.instance_eval(&to_undefine)
+lib/rspec/core/shared_example_group.rb:          Module.class_exec(&to_undefine)

spec/command_line/order_spec.rb

@@ -1,12 +1,12 @@
 require 'spec_helper'
 
-describe 'command line', :ui do
+RSpec.describe 'command line', :ui do
   let(:stderr) { StringIO.new }
   let(:stdout) { StringIO.new }
 
   before :all do
     write_file 'spec/simple_spec.rb', """
-      describe 'group 1' do
+      RSpec.describe 'group 1' do
         specify('group 1 example 1') {}
         specify('group 1 example 2') {}
         specify('group 1 example 3') {}
@@ -19,7 +19,7 @@
     """
 
     write_file 'spec/simple_spec2.rb', """
-      describe 'group 2' do
+      RSpec.describe 'group 2' do
         specify('group 2 example 1') {}
         specify('group 2 example 2') {}
         specify('group 2 example 3') {}
@@ -32,7 +32,7 @@
     """
 
     write_file 'spec/order_spec.rb', """
-      describe 'group 1' do
+      RSpec.describe 'group 1' do
         specify('group 1 example 1')  {}
         specify('group 1 example 2')  {}
         specify('group 1 example 3')  {}
@@ -68,15 +68,15 @@
         describe('group 1-10') { specify('example') {} }
       end
 
-      describe('group 2')  { specify('example') {} }
-      describe('group 3')  { specify('example') {} }
-      describe('group 4')  { specify('example') {} }
-      describe('group 5')  { specify('example') {} }
-      describe('group 6')  { specify('example') {} }
-      describe('group 7')  { specify('example') {} }
-      describe('group 8')  { specify('example') {} }
-      describe('group 9')  { specify('example') {} }
-      describe('group 10') { specify('example') {} }
+      RSpec.describe('group 2')  { specify('example') {} }
+      RSpec.describe('group 3')  { specify('example') {} }
+      RSpec.describe('group 4')  { specify('example') {} }
+      RSpec.describe('group 5')  { specify('example') {} }
+      RSpec.describe('group 6')  { specify('example') {} }
+      RSpec.describe('group 7')  { specify('example') {} }
+      RSpec.describe('group 8')  { specify('example') {} }
+      RSpec.describe('group 9')  { specify('example') {} }
+      RSpec.describe('group 10') { specify('example') {} }
     """
   end
 
@@ -158,14 +158,14 @@
           end
         end
 
-        describe 'group B' do
+        RSpec.describe 'group B' do
           specify('group B example D')  {}
           specify('group B example B')  {}
           specify('group B example A')  {}
           specify('group B example C')  {}
         end
 
-        describe 'group A' do
+        RSpec.describe 'group A' do
           specify('group A example 1')  {}
         end
       """

spec/rspec/core/backtrace_formatter_spec.rb

@@ -1,7 +1,7 @@
 require "spec_helper"
 
 module RSpec::Core
-  describe BacktraceFormatter do
+  RSpec.describe BacktraceFormatter do
     def make_backtrace_formatter(exclusion_patterns=nil, inclusion_patterns=nil)
       BacktraceFormatter.new.tap do |bc|
         bc.exclusion_patterns = exclusion_patterns if exclusion_patterns

spec/rspec/core/command_line_spec.rb

@@ -3,19 +3,23 @@
 require 'tmpdir'
 
 module RSpec::Core
-  describe CommandLine do
+  RSpec.describe CommandLine do
 
     let(:out)    { StringIO.new         }
     let(:err)    { StringIO.new         }
     let(:config) { RSpec::configuration }
     let(:world)  { RSpec::world         }
 
-    before { allow(config.hooks).to receive(:run) }
+    before do
+      allow(config.hooks).to receive(:run)
+      allow(config).to receive(:expose_dsl_globally?).and_return(false)
+    end
 
     it "configures streams before command line options" do
+      allow(RSpec).to receive(:deprecate)  # remove this and should_receive when ordered
       stdout = StringIO.new
-      allow(config).to receive :load_spec_files
-      allow(config).to receive_messages(:reporter => double.as_null_object)
+      allow(config).to receive(:load_spec_files)
+      allow(config).to receive(:reporter).and_return(double.as_null_object)
       config.output_stream = $stdout
 
       # this is necessary to ensure that color works correctly on windows