Refactor config shared context. Simplify some specs.

lib/rubocop/rspec/shared_contexts.rb

@@ -38,26 +38,66 @@
   end
 end
 
-# `cop_config` must be declared with #let.
-RSpec.shared_context 'config', :config do
-  let(:config) do
-    # Module#<
-    raise '`config` must be used in `describe SomeCopClass do .. end`' unless described_class < RuboCop::Cop::Cop
-
-    hash = { 'AllCops' => { 'TargetRubyVersion' => ruby_version } }
-    hash['AllCops']['TargetRailsVersion'] = rails_version if rails_version
-    if respond_to?(:cop_config)
-      cop_name = described_class.cop_name
-      hash[cop_name] = RuboCop::ConfigLoader
-                       .default_configuration[cop_name]
-                       .merge('Enabled' => true) # in case it is 'pending'
-                       .merge(cop_config)
+# This context assumes nothing and defines `cop`, among others.
+RSpec.shared_context 'config', :config do # rubocop:disable Metrics/BlockLength
+  ### Meant to be overriden at will
+
+  let(:source) { 'code = {some: :ruby}' }
+
+  let(:cop_class) do
+    if described_class.is_a?(Class) && described_class < RuboCop::Cop::Cop
+      described_class
+    else
+      RuboCop::Cop::Cop
     end
+  end
+
+  let(:cop_config) { {} }
+
+  let(:other_cops) { {} }
+
+  let(:cop_options) { {} }
+
+  ### Utilities
+
+  def source_range(range, buffer: source_buffer)
+    Parser::Source::Range.new(buffer, range.begin,
+                              range.exclude_end? ? range.end : range.end + 1)
+  end
 
-    hash = other_cops.merge hash if respond_to?(:other_cops)
+  ### Usefull intermediary steps (less likely to be overriden)
+
+  let(:processed_source) { parse_source(source, 'test') }
+
+  let(:source_buffer) { processed_source.buffer }
+
+  let(:all_cops_config) do
+    rails = { 'TargetRubyVersion' => ruby_version }
+    rails['TargetRailsVersion'] = rails_version if rails_version
+    rails
+  end
+
+  let(:cur_cop_config) do
+    RuboCop::ConfigLoader
+      .default_configuration.for_cop(cop_class)
+      .merge({
+               'Enabled' => true, # in case it is 'pending'
+               'AutoCorrect' => true # in case defaults set it to false
+             })
+      .merge(cop_config)
+  end
+
+  let(:config) do
+    hash = { 'AllCops' => all_cops_config,
+             cop_class.cop_name => cur_cop_config }.merge!(other_cops)
 
     RuboCop::Config.new(hash, "#{Dir.pwd}/.rubocop.yml")
   end
+
+  let(:cop) do
+    cop_class.new(config, cop_options)
+             .tap { |cop| cop.processed_source = processed_source }
+  end
 end
 
 RSpec.shared_context 'mock console output' do

spec/rubocop/cop/alignment_corrector_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-RSpec.describe RuboCop::Cop::AlignmentCorrector do
-  let(:cop) { RuboCop::Cop::Test::AlignmentDirective.new }
+RSpec.describe RuboCop::Cop::AlignmentCorrector, :config do
+  let(:cop_class) { RuboCop::Cop::Test::AlignmentDirective }
 
   describe '#correct' do
     context 'simple indentation' do

spec/rubocop/cop/cop_spec.rb

@@ -1,12 +1,8 @@
 # frozen_string_literal: true
 
-RSpec.describe RuboCop::Cop::Cop do
-  subject(:cop) { described_class.new }
-
+RSpec.describe RuboCop::Cop::Cop, :config do
   let(:location) do
-    source_buffer = Parser::Source::Buffer.new('test', 1)
-    source_buffer.source = "a\n"
-    Parser::Source::Range.new(source_buffer, 0, 1)
+    source_range(0...1)
   end
 
   it 'initially has 0 offenses' do
@@ -90,32 +86,41 @@
       .to output(/Warning: Invalid severity 'superbad'./).to_stderr
   end
 
-  it 'will set offense as disabled if ignore_disable_comments is false' do
-    comment_config = instance_double(RuboCop::CommentConfig,
-                                     cop_enabled_at_line?: false)
-    processed_source = instance_double(RuboCop::ProcessedSource,
-                                       comment_config: comment_config)
-    cop.processed_source = processed_source
-    cop.instance_variable_set(:@options, ignore_disable_comments: false)
-    cop.add_offense(nil, location: location, message: 'message')
-    expect(cop.offenses.first.status).to eq :disabled
-  end
+  context 'when disabled by a comment' do
+    subject(:offense_status) do
+      cop.add_offense(nil, location: location, message: 'message')
+      cop.offenses.first.status
+    end
 
-  it 'will not set offense as disabled if ignore_disable_comments is true' do
-    comment_config = instance_double(RuboCop::CommentConfig,
-                                     cop_enabled_at_line?: false)
-    processed_source = instance_double(RuboCop::ProcessedSource,
-                                       comment_config: comment_config)
-    cop.processed_source = processed_source
-    cop.instance_variable_set(:@options, ignore_disable_comments: true)
-    cop.add_offense(nil, location: location, message: 'message')
-    expect(cop.offenses.first.status).not_to eq :disabled
+    before do
+      allow(processed_source.comment_config).to receive(:cop_enabled_at_line?)
+        .and_return(false)
+    end
+
+    context 'ignore_disable_comments is false' do
+      let(:cop_options) { { ignore_disable_comments: false } }
+
+      it 'will set offense as disabled' do
+        expect(offense_status).to eq :disabled
+      end
+    end
+
+    context 'ignore_disable_comments is true' do
+      let(:cop_options) { { ignore_disable_comments: true } }
+
+      it 'will not set offense as disabled' do
+        expect(offense_status).not_to eq :disabled
+      end
+    end
   end
 
-  it 'registers offense with its name' do
-    cop = RuboCop::Cop::Style::For.new
-    cop.add_offense(nil, location: location, message: 'message')
-    expect(cop.offenses.first.cop_name).to eq('Style/For')
+  describe 'for a cop with a name' do
+    let(:cop_class) { RuboCop::Cop::Style::For }
+
+    it 'registers offense with its name' do
+      cop.add_offense(nil, location: location, message: 'message')
+      expect(cop.offenses.first.cop_name).to eq('Style/For')
+    end
   end
 
   describe 'setting of Offense#corrected attribute' do
@@ -161,7 +166,7 @@
     end
 
     context 'when cop supports autocorrection' do
-      let(:cop) { RuboCop::Cop::Style::Alias.new }
+      let(:cop_class) { RuboCop::Cop::Style::Alias }
 
       context 'when offense was corrected' do
         before do
@@ -201,24 +206,22 @@
   end
 
   context 'with no submodule' do
-    subject(:cop) { described_class }
-
-    it('has right name') { expect(cop.cop_name).to eq('Cop/Cop') }
-    it('has right department') { expect(cop.department).to eq(:Cop) }
+    it('has right name') { expect(cop_class.cop_name).to eq('Cop/Cop') }
+    it('has right department') { expect(cop_class.department).to eq(:Cop) }
   end
 
   context 'with style cops' do
-    subject(:cop) { RuboCop::Cop::Style::For }
+    let(:cop_class) { RuboCop::Cop::Style::For }
 
-    it('has right name') { expect(cop.cop_name).to eq('Style/For') }
-    it('has right department') { expect(cop.department).to eq(:Style) }
+    it('has right name') { expect(cop_class.cop_name).to eq('Style/For') }
+    it('has right department') { expect(cop_class.department).to eq(:Style) }
   end
 
   context 'with lint cops' do
-    subject(:cop) { RuboCop::Cop::Lint::Loop }
+    let(:cop_class) { RuboCop::Cop::Lint::Loop }
 
-    it('has right name') { expect(cop.cop_name).to eq('Lint/Loop') }
-    it('has right department') { expect(cop.department).to eq(:Lint) }
+    it('has right name') { expect(cop_class.cop_name).to eq('Lint/Loop') }
+    it('has right department') { expect(cop_class.department).to eq(:Lint) }
   end
 
   describe 'Registry' do
@@ -262,8 +265,6 @@
 
     subject { cop.autocorrect? }
 
-    let(:config) { RuboCop::Config.new({}) }
-    let(:cop) { described_class.new(config, options) }
     let(:support_autocorrect) { true }
     let(:disable_uncorrectable) { false }
 
@@ -279,7 +280,7 @@
     end
 
     context 'when the option is given' do
-      let(:options) { { auto_correct: true } }
+      let(:cop_options) { { auto_correct: true } }
 
       it { is_expected.to be(true) }
 
@@ -296,9 +297,7 @@
       end
 
       context 'when the cop is set to not autocorrect' do
-        let(:config) do
-          RuboCop::Config.new('Cop/Cop' => { 'AutoCorrect' => false })
-        end
+        let(:cop_options) { { 'AutoCorrect' => false } }
 
         it { is_expected.to be(false) }
       end
@@ -308,9 +307,6 @@
   describe '#safe_autocorrect?' do
     subject { cop.safe_autocorrect? }
 
-    let(:config) { RuboCop::Config.new('Cop/Cop' => cop_config) }
-    let(:cop) { described_class.new(config) }
-
     context 'when cop is declared unsafe' do
       let(:cop_config) { { 'Safe' => false } }
 

spec/rubocop/cop/lint/redundant_cop_disable_directive_spec.rb

@@ -1,16 +1,8 @@
 # frozen_string_literal: true
 
-RSpec.describe RuboCop::Cop::Lint::RedundantCopDisableDirective do
+RSpec.describe RuboCop::Cop::Lint::RedundantCopDisableDirective, :config do
   describe '.check' do
-    let(:cop) do
-      cop = described_class.new
-      cop.instance_variable_get(:@options)[:auto_correct] = true
-      cop.processed_source = processed_source
-      cop
-    end
-    let(:processed_source) do
-      RuboCop::ProcessedSource.new(source, ruby_version)
-    end
+    let(:cop_options) { { auto_correct: true } }
     let(:comments) { processed_source.comments }
     let(:corrected_source) do
       RuboCop::Cop::Corrector
@@ -246,9 +238,9 @@
                           'Unnecessary disabling of `Lint/Debugger`.'])
                 expect(cop.highlights).to eq(%w[ClassLength Debugger])
                 expect($stderr.string).to eq(<<~OUTPUT)
-                  (string): Warning: no department given for MethodLength.
-                  (string): Warning: no department given for ClassLength.
-                  (string): Warning: no department given for Debugger.
+                  test: Warning: no department given for MethodLength.
+                  test: Warning: no department given for ClassLength.
+                  test: Warning: no department given for Debugger.
                 OUTPUT
               end
             end

spec/rubocop/cop/style/guard_clause_spec.rb

@@ -1,18 +1,15 @@
 # frozen_string_literal: true
 
-RSpec.describe RuboCop::Cop::Style::GuardClause do
-  let(:cop) { described_class.new(config) }
-  let(:config) do
-    RuboCop::Config.new(
+RSpec.describe RuboCop::Cop::Style::GuardClause, :config do
+  let(:other_cops) do
+    {
       'Layout/LineLength' => {
         'Enabled' => line_length_enabled,
         'Max' => 80
-      },
-      'Style/GuardClause' => cop_config
-    )
+      }
+    }
   end
   let(:line_length_enabled) { true }
-  let(:cop_config) { {} }
 
   shared_examples 'reports offense' do |body|
     it 'reports an offense if method body is if / unless without else' do

spec/rubocop/formatter/clang_style_formatter_spec.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-RSpec.describe RuboCop::Formatter::ClangStyleFormatter do
+RSpec.describe RuboCop::Formatter::ClangStyleFormatter, :config do
   subject(:formatter) { described_class.new(output) }
 
   let(:output) { StringIO.new }
@@ -13,16 +13,13 @@
                                 'This is a message.', 'CopName', status)
     end
 
+    let(:source) { ('aa'..'az').to_a.join($RS) }
+
     let(:location) do
-      source_buffer = Parser::Source::Buffer.new('test', 1)
-      source_buffer.source = "a\n"
-      Parser::Source::Range.new(source_buffer, 0, 1)
+      source_range(0...1)
     end
 
     it 'displays text containing the offending source line' do
-      cop = RuboCop::Cop::Cop.new
-      source_buffer = Parser::Source::Buffer.new('test', 1)
-      source_buffer.source = ('aa'..'az').to_a.join($RS)
       cop.add_offense(
         nil,
         location: Parser::Source::Range.new(source_buffer, 0, 2),
@@ -46,10 +43,9 @@
     end
 
     context 'when the source line is blank' do
+      let(:source) { ['     ', 'yaba'].join($RS) }
+
       it 'does not display offending source line' do
-        cop = RuboCop::Cop::Cop.new
-        source_buffer = Parser::Source::Buffer.new('test', 1)
-        source_buffer.source = ['     ', 'yaba'].join($RS)
         cop.add_offense(
           nil,
           location: Parser::Source::Range.new(source_buffer, 0, 2),
@@ -72,21 +68,17 @@
     end
 
     context 'when the offending source spans multiple lines' do
-      it 'displays the first line with ellipses' do
-        source = <<~RUBY
+      let(:source) do
+        <<~RUBY
           do_something([this,
                         is,
                         target])
         RUBY
+      end
 
-        source_buffer = Parser::Source::Buffer.new('test', 1)
-        source_buffer.source = source
-
-        location = Parser::Source::Range.new(source_buffer,
-                                             source.index('['),
-                                             source.index(']') + 1)
+      it 'displays the first line with ellipses' do
+        location = source_range(source.index('[')..source.index(']'))
 
-        cop = RuboCop::Cop::Cop.new
         cop.add_offense(nil, location: location, message: 'message 1')
 
         formatter.report_file('test', cop.offenses)