Emit a warning for around(:context)

fixes #2486

Changelog.md

@@ -6,6 +6,8 @@ Bug Fixes:
 * Prevent bisect command from blocking when number of specs exceeds file
   descriptor limit on OSX or Linux. (Benoit Tigeot, #2669)
 * Prevent warnings being issued on Ruby 2.7.0. (Jon Rowe, #2680)
+* Emit a warning when `around` hook is used with `:context` scope
+  (Phil Pirozhkov, #2687)
 
 ### 3.9.0 / 2019-10-07
 [Full Changelog](http://github.com/rspec/rspec-core/compare/v3.8.2...v3.9.0)

lib/rspec/core/hooks.rb

@@ -448,6 +448,11 @@ def register(prepend_or_append, position, *args, &block)
                             "`#{position}(:suite)` hook, registered on an example " \
                             "group, will be ignored."
             return
+          elsif scope == :context && position == :around
+            # TODO: consider making this an error in RSpec 4. For SemVer reasons,
+            # we are only warning in RSpec 3.
+            RSpec.warn_with "WARNING: `around(:context)` hooks are not supported and " \
+                            "behave like `around(:example)."
           end
 
           hook = HOOK_TYPES[position][scope].new(block, options)

spec/rspec/core/hooks_spec.rb

@@ -492,5 +492,34 @@ def yielder
         :hooks
       ])
     end
+
+    it 'emits a warning for `around(:context)`' do
+      expect(RSpec).to receive(:warn_with).with(a_string_including(
+        '`around(:context)` hooks are not supported'
+      ))
+      RSpec.describe do
+        around(:context) { }
+      end
+    end
+
+    it 'emits a warning for `around(:context)` defined in `configure`' do
+      expect(RSpec).to receive(:warn_with).with(a_string_including(
+        '`around(:context)` hooks are not supported'
+      ))
+      RSpec.configure do |c|
+        c.around(:context) { }
+      end
+    end
+
+    [:before, :around, :after].each do |type|
+      it "emits a warning for `#{type}(:suite)` hooks" do
+        expect(RSpec).to receive(:warn_with).with(a_string_including(
+          "`#{type}(:suite)` hooks are only supported on the RSpec configuration object."
+        ))
+        RSpec.describe do
+          send(type, :suite) { }
+        end
+      end
+    end
   end
 end