(puppetlabsGH-2543) Block publishing events while prompting and parallel

This will block the executor from continuing to publish events until the
user has entered input for a prompt. This prevents prompts inside of
parallelize blocks from being interleaved with output from the block
continuing to execute.

This also adds a known issue that output from `resolve_reference` that
uses `prompt` inside a parallel block may not be a good user experience.

Lastly, this adjusts the spinner while running in parallel to
pessimistically spin - that is, only spin if it's started by a
long-running process and not stopped. This includes sending the `spin:
stop` message to the spinner at any point that a
non-long-running-process (like prompt) might begin.

Closes puppetlabs#2543

!bug

* **Don't continue executing parallel block when prompting** ([puppetlabs#2543](puppetlabs#2543))
  Bolt will now pause printing messages from parallel blocks when
  prompting the user for input, to avoid confusing printing to the screen.

lib/bolt/executor.rb

@@ -100,6 +100,8 @@ def publish_event(event)
         # that type of event, publish the event
         next unless types.nil? || types.include?(event[:type])
         @publisher.post(subscriber) do |sub|
+          # Wait for user to input to prompt before printing anything
+          sleep(0.1) while @prompting
           sub.handle_event(event)
         end
       end
@@ -412,7 +414,7 @@ def round_robin(skein)
       subscribe(self, [:node_result])
       results = Array.new(skein.length)
       @in_parallel = true
-      publish_event(type: :start_spin)
+      publish_event(type: :stop_spin)
 
       until skein.empty?
         @thread_completed = false
@@ -474,18 +476,19 @@ def wait_until(timeout, retry_interval)
     end
 
     def prompt(prompt, options)
+      @prompting = true
       unless $stdin.tty?
         raise Bolt::Error.new('STDIN is not a tty, unable to prompt', 'bolt/no-tty-error')
       end
 
-      sleep(0.1) if @in_parallel
       $stderr.print("#{prompt}: ")
 
       value = if options[:sensitive]
                 $stdin.noecho(&:gets).to_s.chomp
               else
                 $stdin.gets.to_s.chomp
               end
+      @prompting = false
 
       $stderr.puts if options[:sensitive]
 

lib/bolt/outputter/rainbow.rb

@@ -63,12 +63,12 @@ def colorize(color, string)
       end
 
       def start_spin
-        return unless @spin && @stream.isatty
-        @spin = true
+        return unless @spin && @stream.isatty && !@spinning
+        @spinning = true
         @spin_thread = Thread.new do
           loop do
-            @stream.print(colorize(:rainbow, @pinwheel.rotate!.first + "\b"))
             sleep(0.1)
+            @stream.print(colorize(:rainbow, @pinwheel.rotate!.first + "\b"))
           end
         end
       end

spec/bolt/executor_spec.rb

@@ -863,7 +863,7 @@ def mock_node_results
       executor.round_robin([])
     end
 
-    it "starts and stops the spinner" do
+    it "stops the spinner" do
       skein = %w[a b c d].each_with_index.map do |val, index|
         fiber = Fiber.new do
           sleep(rand(0.01..0.1))
@@ -873,7 +873,7 @@ def mock_node_results
       end
 
       executor.round_robin(skein)
-      expect(collector.events).to include({ type: :start_spin })
+      expect(collector.events).to include({ type: :stop_spin })
     end
 
     it "returns results in the same order they were originally" do