Add ContextWorking cop. Resolves rubocop#417

geniou · geniou · commit 0290b72b6ea0 · 2019-04-03T11:34:30.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 * Fixed `RSpec/ContextWording` missing `context`s with metadata. ([@pirj][])
 * Fix `FactoryBot/AttributeDefinedStatically` not working with an explicit receiver. ([@composerinteralia][])
+* Add `RSpec/ContextMethod` cop, to detect method names in `context`. ([@geniou][])
 
 ## 1.32.0 (2019-01-27)
 
diff --git a/config/default.yml b/config/default.yml
@@ -49,6 +49,11 @@ RSpec/BeforeAfterAll:
   - spec/support/**/*.rb
   StyleGuide: http://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/BeforeAfterAll
 
+RSpec/ContextMethod:
+  Description: "`context` should not be used for specifying methods."
+  Enabled: true
+  StyleGuide: http://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/ContextMethod
+
 RSpec/ContextWording:
   Description: "`context` block descriptions should start with 'when', or 'with'."
   Enabled: true
diff --git a/lib/rubocop/cop/rspec/context_method.rb b/lib/rubocop/cop/rspec/context_method.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module RSpec
+      # `context` should not be used for specifying methods.
+      #
+      # @example
+      #   # bad
+      #   context '#foo_bar' do
+      #     # ...
+      #   end
+      #
+      #   context '.foo_bar' do
+      #     # ...
+      #   end
+      #
+      #   # good
+      #   describe '#foo_bar' do
+      #     # ...
+      #   end
+      #
+      #   describe '.foo_bar' do
+      #     # ...
+      #   end
+      class ContextMethod < Cop
+        MSG = 'Use describe for testing methods.'.freeze
+        METHOD_INDICATORS = %w[. #].freeze
+
+        def_node_matcher :context_method, <<-PATTERN
+          (block (send #{RSPEC} { :context } $(str #method_name?) ...) ...)
+        PATTERN
+
+        def on_block(node)
+          context_method(node) do |context|
+            add_offense(context, message: MSG)
+          end
+        end
+
+        def autocorrect(node)
+          lambda do |corrector|
+            corrector.replace(node.parent.loc.selector, 'describe')
+          end
+        end
+
+        private
+
+        def method_name?(description)
+          METHOD_INDICATORS.include?(description[0])
+        end
+      end
+    end
+  end
+end
diff --git a/lib/rubocop/cop/rspec_cops.rb b/lib/rubocop/cop/rspec_cops.rb
@@ -17,6 +17,7 @@
 require_relative 'rspec/be'
 require_relative 'rspec/be_eql'
 require_relative 'rspec/before_after_all'
+require_relative 'rspec/context_method'
 require_relative 'rspec/context_wording'
 require_relative 'rspec/describe_class'
 require_relative 'rspec/describe_method'
diff --git a/manual/cops.md b/manual/cops.md
@@ -18,6 +18,7 @@
 * [RSpec/Be](cops_rspec.md#rspecbe)
 * [RSpec/BeEql](cops_rspec.md#rspecbeeql)
 * [RSpec/BeforeAfterAll](cops_rspec.md#rspecbeforeafterall)
+* [RSpec/ContextMethod](cops_rspec.md#rspeccontextmethod)
 * [RSpec/ContextWording](cops_rspec.md#rspeccontextwording)
 * [RSpec/DescribeClass](cops_rspec.md#rspecdescribeclass)
 * [RSpec/DescribeMethod](cops_rspec.md#rspecdescribemethod)
diff --git a/manual/cops_rspec.md b/manual/cops_rspec.md
@@ -233,6 +233,40 @@ Exclude | `spec/spec_helper.rb`, `spec/rails_helper.rb`, `spec/support/**/*.rb`
 
 * [http://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/BeforeAfterAll](http://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/BeforeAfterAll)
 
+## RSpec/ContextMethod
+
+Enabled by default | Supports autocorrection
+--- | ---
+Enabled | Yes
+
+`context` should not be used for specifying methods.
+
+### Examples
+
+```ruby
+# bad
+context '#foo_bar' do
+  # ...
+end
+
+context '.foo_bar' do
+  # ...
+end
+
+# good
+describe '#foo_bar' do
+  # ...
+end
+
+describe '.foo_bar' do
+  # ...
+end
+```
+
+### References
+
+* [http://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/ContextMethod](http://www.rubydoc.info/gems/rubocop-rspec/RuboCop/Cop/RSpec/ContextMethod)
+
 ## RSpec/ContextWording
 
 Enabled by default | Supports autocorrection
diff --git a/spec/rubocop/cop/rspec/context_method_spec.rb b/spec/rubocop/cop/rspec/context_method_spec.rb
@@ -0,0 +1,37 @@
+RSpec.describe RuboCop::Cop::RSpec::ContextMethod do
+  subject(:cop) { described_class.new }
+
+  it 'skips describe blocks' do
+    expect_no_offenses(<<-RUBY)
+      describe '.foo_bar' do
+      end
+
+      describe '#foo_bar' do
+      end
+    RUBY
+  end
+
+  it 'finds context with `.` at the beginning' do
+    expect_offense(<<-RUBY)
+      context '.foo_bar' do
+              ^^^^^^^^^^ Use describe for testing methods.
+      end
+    RUBY
+  end
+
+  it 'finds context with `#` at the beginning' do
+    expect_offense(<<-RUBY)
+      context '#foo_bar' do
+              ^^^^^^^^^^ Use describe for testing methods.
+      end
+    RUBY
+  end
+
+  include_examples 'autocorrect',
+                   'context ".foo_bar" do; end',
+                   'describe ".foo_bar" do; end'
+
+  include_examples 'autocorrect',
+                   'context "#foo_bar" do; end',
+                   'describe "#foo_bar" do; end'
+end
