Merge pull request #1880 from rspec/allowed-stdlibs

Allowed stdlibs

Author: JonRowe

lib/rspec/core.rb

@@ -2,8 +2,6 @@
 $_rspec_core_load_started_at = Time.now
 # rubocop:enable Style/GlobalVars
 
-require 'rbconfig'
-
 require "rspec/support"
 RSpec::Support.require_rspec_support "caller_filter"
 

spec/rspec/core/backtrace_formatter_spec.rb

@@ -112,7 +112,7 @@ def make_backtrace_formatter(exclusion_patterns=nil, inclusion_patterns=nil)
 
         expect(BacktraceFormatter.new.format_backtrace(backtrace)).to eq(["./my_spec.rb:5"])
       end
-      
+
       context "when every line is filtered out" do
         let(:backtrace) do
           [

spec/rspec/core_spec.rb

@@ -1,25 +1,65 @@
-require 'rspec/support/spec/prevent_load_time_warnings'
+require 'rspec/support/spec/library_wide_checks'
 
 RSpec.describe RSpec do
-  fake_minitest = File.expand_path('../../support/fake_minitest', __FILE__)
-  it_behaves_like 'a library that issues no warnings when loaded', 'rspec-core',
-    # Loading minitest issues warnings, so we put our fake minitest on the load
-    # path to prevent the real minitest from being loaded.
-    "$LOAD_PATH.unshift '#{fake_minitest}'", 'require "rspec/core"', 'RSpec::Core::Runner.disable_autorun!' do
-
-    pending_when = {
-      '1.9.2' => { :description => "issues no warnings when loaded" },
-      '1.8.7' => { :description => "issues no warnings when the spec files are loaded" },
-      '2.0.0' => { }
-    }
-
-    if RUBY_VERSION == '1.9.2' || RUBY_VERSION == '1.8.7'
-      before(:example, pending_when.fetch(RUBY_VERSION)) do
+  fake_libs = File.expand_path('../../support/fake_libs', __FILE__)
+  allowed_loaded_features = [
+    /optparse\.rb/,   # Used by OptionParser.
+    /set\.rb/,        # used in a few places but being removed in #1870.
+    /rbconfig\.rb/,   # loaded by rspec-support for OS detection.
+    /shellwords\.rb/, # used by ConfigurationOptions and RakeTask.
+    /stringio/,       # Used by BaseFormatter.
+    %r{/fake_libs/},  # ignore these, obviously
+  ]
+
+  # JRuby appears to not respect `--disable=gem` so rubygems also gets loaded.
+  allowed_loaded_features << /rubygems/ if RSpec::Support::Ruby.jruby?
+
+  it_behaves_like 'library wide checks', 'rspec-core',
+    :preamble_for_lib => [
+      # rspec-core loads a number of external libraries. We don't want them loaded
+      # as part of loading all of rspec-core for these specs, for a few reasons:
+      #
+      #   * Some external libraries issue warnings, which we can't do anything about.
+      #     Since we are trying to prevent _any_ warnings from loading RSpec, it's
+      #     easiest to avoid loading those libraries entirely.
+      #   * Some external libraries load many stdlibs. Here we allow a known set of
+      #     directly loaded stdlibs, and we're not directly concerned with transitive
+      #     dependencies.
+      #   * We're really only concerned with these issues w.r.t. rspec-mocks and
+      #     rspec-expectations from within their spec suites. Here we care only about
+      #     rspec-core, so avoiding loading them helps keep the spec suites independent.
+      #   * These are some of the slowest specs we have, and cutting out the loading
+      #     of external libraries cuts down on how long these specs take.
+      #
+      # To facilitate the avoidance of loading certain libraries, we have a bunch
+      # of files in `support/fake_libs` that substitute for the real things when
+      # we put that directory on the load path. Here's the list:
+      #
+      #   * coderay -- loaded by the HTML formatter if availble for syntax highlighting.
+      #   * drb -- loaded when `--drb` is used. Loads other stdlibs (socket, thread, fcntl).
+      #   * erb -- loaded by `ConfigurationOptions` so `.rspec` can use ERB. Loads other stdlibs (strscan, cgi/util).
+      #   * flexmock -- loaded by our Flexmock mocking adapter.
+      #   * json -- loaded by the JSON formatter, loads other stdlibs (ostruct, enc/utf_16le.bundle, etc).
+      #   * minitest -- loaded by our Minitest assertions adapter.
+      #   * mocha -- loaded by our Mocha mocking adapter.
+      #   * rake -- loaded by our Rake task. Loads other stdlibs (fileutils, ostruct, thread, monitor, etc).
+      #   * rr -- loaded by our RR mocking adapter.
+      #   * rspec-mocks -- loaded by our RSpec mocking adapter.
+      #   * rspec-expectations -- loaded by the generated `spec_helper` (defined in project_init).
+      #   * test-unit -- loaded by our T::U assertions adapter.
+      #
+      "$LOAD_PATH.unshift '#{fake_libs}'",
+      # Many files assume this has already been loaded and will have errors if it has not.
+      'require "rspec/core"',
+      # Prevent rspec/autorun from trying to run RSpec.
+      'RSpec::Core::Runner.disable_autorun!'
+    ], :skip_spec_files => %r{/fake_libs/}, :allowed_loaded_feature_regexps => allowed_loaded_features do
+    if RUBY_VERSION == '1.8.7'
+      before(:example, :description => /(issues no warnings when the spec files are loaded|stdlibs)/) do
         pending "Not working on #{RUBY_DESCRIPTION}"
       end
-    end
-    if (RUBY_PLATFORM == 'java' && RUBY_VERSION == '2.0.0')
-      before(:example, pending_when.fetch(RUBY_VERSION)) do
+    elsif RUBY_VERSION == '2.0.0' && RSpec::Support::Ruby.jruby?
+      before(:example) do
         skip "Not reliably working on #{RUBY_DESCRIPTION}"
       end
     end

spec/spec_helper.rb

@@ -22,6 +22,10 @@ def self.new(*args, &block)
 end
 
 Dir['./spec/support/**/*.rb'].map do |file|
+  # fake libs aren't intended to be loaded except by some specific specs
+  # that shell out and run a new process.
+  next if file =~ /fake_libs/
+
   # Ensure requires are relative to `spec`, which is on the
   # load path. This helps prevent double requires on 1.8.7.
   require file.gsub("./spec/support", "support")

spec/support/fake_minitest/minitest.rb renamed to spec/support/fake_libs/coderay.rb

@@ -0,0 +1,4 @@
+module ERB
+  module Util
+  end
+end

spec/support/fake_libs/drb/drb.rb

@@ -0,0 +1,4 @@
+module FlexMock
+  module MockContainer
+  end
+end

spec/support/fake_libs/erb.rb

@@ -0,0 +1,4 @@
+module Mocha
+  module API
+  end
+end

spec/support/fake_libs/flexmock/rspec.rb

@@ -0,0 +1,4 @@
+module Rake
+  class TaskLib
+  end
+end

spec/support/fake_libs/json.rb

@@ -0,0 +1,10 @@
+module RR
+  module Errors
+    BACKTRACE_IDENTIFIER = /doesn't matter/
+  end
+
+  module Extensions
+    module InstanceMethods
+    end
+  end
+end

spec/support/fake_libs/minitest.rb

@@ -0,0 +1,8 @@
+module RSpec
+  module Expectations
+  end
+
+  module Matchers
+    def self.configuration; RSpec::Core::NullReporter; end
+  end
+end

spec/support/fake_minitest/minitest/minitest_assertions.rb renamed to spec/support/fake_libs/minitest/assertions.rb

@@ -0,0 +1,8 @@
+module RSpec
+  module Mocks
+    module ExampleMethods
+    end
+
+    def self.configuration; RSpec::Core::NullReporter; end
+  end
+end