Warn on context fixture helper

.travis.yml

@@ -3,24 +3,24 @@ language: ruby
 rvm:
   - 1.8.7
   - 2.1.4
-  - 2.1.3
-  - 2.1.2
-  - 2.1.1
-  - 2.1.0
-  - 2.0.0
-  - 1.9.3
-  - 1.9.2
+#  - 2.1.3
+#  - 2.1.2
+#  - 2.1.1
+#  - 2.1.0
+#  - 2.0.0
+#  - 1.9.3
+#  - 1.9.2
 
 env:
   - RAILS_VERSION='~> 4.2.0.beta2'
-  - RAILS_VERSION=master
+#  - RAILS_VERSION=master
   - RAILS_VERSION='~> 4.1.0'
-  - RAILS_VERSION=4-1-stable
-  - RAILS_VERSION='~> 4.0.4'
-  - RAILS_VERSION=4-0-stable
-  - RAILS_VERSION='~> 3.2.17'
-  - RAILS_VERSION=3-2-stable
-  - RAILS_VERSION='~> 3.1.12'
+#  - RAILS_VERSION=4-1-stable
+#  - RAILS_VERSION='~> 4.0.4'
+#  - RAILS_VERSION=4-0-stable
+#  - RAILS_VERSION='~> 3.2.17'
+#  - RAILS_VERSION=3-2-stable
+#  - RAILS_VERSION='~> 3.1.12'
   - RAILS_VERSION='~> 3.0.20'
 
 sudo: false

lib/rspec/rails/fixture_context_helpers.rb

@@ -0,0 +1,72 @@
+module RSpec
+  module Rails
+    # @private
+    module FixtureContextHelpers
+      # @private
+      module TrackableFixtures
+        def known_fixtures
+          @_known_fixtures ||= []
+        end
+
+        def to_s
+          "#{super}(#{known_fixtures.sort.join(', ')})"
+        end
+        alias_method :inspect, :to_s
+      end
+
+    private
+
+      def convert_to_accessors(names)
+        names.map { |n| n.to_s.tr('/', '_').to_sym }
+      end
+
+      def ensure_prevent_fixture_helpers
+        if const_defined?(:PreventFixtures, false)
+          const_get(:PreventFixtures, false)
+        else
+          set_prevent_fixture_helpers
+        end
+      end
+
+      def prevent_fixture_helpers
+        const_get(:PreventFixtures) if const_defined?(:PreventFixtures)
+      end
+
+      def prevent_fixtures_in_context(accessor_names)
+        return if accessor_names.empty?
+        ensure_prevent_fixture_helpers.module_exec do
+          (accessor_names - known_fixtures).each do |accessor_name|
+            known_fixtures << accessor_name
+            define_method(accessor_name) do |*_fixture_names|
+              raise <<-EOS
+Fixture accessor `#{accessor_name}` invoked in a `before` or `after` context hook at:
+  #{CallerFilter.first_non_rspec_line}
+
+Calling fixture accessors from a context hook is not supported.
+
+Active Record fixtures are automatically loaded into the database before each
+example. To ensure consistent data, the environment deletes the fixtures before
+running the load each time.
+
+Fixture accessor helpers are not intended to be called in a context hook, as
+they exist to load database state that is reset between each example, while
+`before(:context)` exists to define state that is shared across examples in an
+example group and `after(:context)` exists to cleanup state that is shared
+across examples in an example group.
+EOS
+            end
+          end
+        end
+      end
+
+      def set_prevent_fixture_helpers
+        existing_helpers = prevent_fixture_helpers
+        mod = Module.new do
+          extend TrackableFixtures
+          include existing_helpers if existing_helpers
+        end
+        const_set(:PreventFixtures, mod)
+      end
+    end
+  end
+end

lib/rspec/rails/fixture_support.rb

@@ -1,3 +1,4 @@
+require_relative 'fixture_context_helpers'
 module RSpec
   module Rails
     # @private
@@ -26,6 +27,34 @@ module FixtureSupport
           self.use_instantiated_fixtures  = RSpec.configuration.use_instantiated_fixtures
           fixtures RSpec.configuration.global_fixtures if RSpec.configuration.global_fixtures
         end
+
+        # @private
+        module ClassMethods
+          include RSpec::Rails::FixtureContextHelpers
+
+          def run_before_context_hooks(example_group_instance)
+            if (_helpers = prevent_fixture_helpers)
+              example_group_instance.extend _helpers
+            end
+            super
+          end
+          private :run_before_context_hooks
+
+          def run_after_context_hooks(example_group_instance)
+            if (_helpers = prevent_fixture_helpers)
+              example_group_instance.extend _helpers
+            end
+            super
+          end
+          private :run_before_context_hooks
+
+          def setup_fixture_accessors(table_names = nil)
+            fixture_set_names = Array(fixture_set_names || fixture_table_names)
+            prevent_fixtures_in_context(convert_to_accessors(fixture_set_names))
+            super
+          end
+          private :setup_fixture_accessors
+        end
       end
     end
   end