Cleanup formatter support a bit.

- Stop memoizing `example`. It made it difficult to
  construct multiple different examples.
- Explicitly create the examples where they are needed.

Author: myronmarston

spec/rspec/core/notifications_spec.rb

@@ -4,9 +4,11 @@
 RSpec.describe "FailedExampleNotification" do
   include FormatterSupport
 
+  let(:example) { new_example }
   let(:notification) { ::RSpec::Core::Notifications::FailedExampleNotification.new(example) }
 
   before do
+    allow(example.execution_result).to receive(:exception) { exception }
     example.metadata[:absolute_file_path] = __FILE__
   end
 

spec/rspec/core/reporter_spec.rb

@@ -66,6 +66,7 @@ module RSpec::Core
       it "passes messages to that formatter" do
         formatter = double("formatter", :example_started => nil)
         reporter.register_listener formatter, :example_started
+        example = new_example
 
         expect(formatter).to receive(:example_started) do |notification|
           expect(notification.example).to eq example
@@ -121,6 +122,7 @@ module RSpec::Core
     context "given multiple formatters" do
       it "passes messages to all formatters" do
         formatters = (1..2).map { double("formatter", :example_started => nil) }
+        example = new_example
 
         formatters.each do |formatter|
           expect(formatter).to receive(:example_started) do |notification|

spec/support/formatter_support.rb

@@ -200,34 +200,28 @@ def formatter
       end
   end
 
-  def example
-    @example ||=
-      begin
-        result = instance_double(RSpec::Core::Example::ExecutionResult,
-                                 :pending_fixed?   => false,
-                                 :example_skipped? => false,
-                                 :status           => :passed
-                                )
-        allow(result).to receive(:exception) { exception }
-        instance_double(RSpec::Core::Example,
-                        :description       => "Example",
-                        :full_description  => "Example",
-                        :execution_result  => result,
-                        :location          => "",
-                        :location_rerun_argument => "",
-                        :metadata          => {
-                          :shared_group_inclusion_backtrace => []
-                        }
-                       )
-      end
-  end
-
-  def exception
-    Exception.new
+  def new_example(metadata = {})
+    result = instance_double(RSpec::Core::Example::ExecutionResult,
+                             :pending_fixed?   => false,
+                             :example_skipped? => false,
+                             :status           => :passed,
+                             :exception        => Exception.new
+                            )
+
+    instance_double(RSpec::Core::Example,
+                     :description             => "Example",
+                     :full_description        => "Example",
+                     :execution_result        => result,
+                     :location                => "",
+                     :location_rerun_argument => "",
+                     :metadata                => {
+                       :shared_group_inclusion_backtrace => []
+                     }.merge(metadata)
+                   )
   end
 
   def examples(n)
-    (1..n).map { example }
+    Array.new(n) { new_example }
   end
 
   def group
@@ -242,7 +236,7 @@ def stop_notification
    ::RSpec::Core::Notifications::ExamplesNotification.new reporter
   end
 
-  def example_notification(specific_example = example)
+  def example_notification(specific_example = new_example)
    ::RSpec::Core::Notifications::ExampleNotification.for specific_example
   end