Refactor helper methods

test/retest/prompt_test.rb

@@ -49,21 +49,6 @@ def test_ask_which_test_to_use
       EXPECTED
     end
 
-    class ListeningIO
-      attr_accessor :io
-      def initialize
-        @io = StringIO.new
-      end
-
-      def gets
-        loop do
-          sleep 0.0001
-          line = @io.gets.to_s
-          break line unless line.empty?
-        end
-      end
-    end
-
     def test_question_asked_when_asking_question
       files = %w(
         test/models/taxation/holdings_test.rb
@@ -73,26 +58,17 @@ def test_question_asked_when_asking_question
         test/lib/csv_report/holdings_test.rb
       )
 
-      @subject.input = stdin = ListeningIO.new
+      @subject.input = stdin = BlockingInput.new
 
       th = Thread.new do
         @subject.ask_which_test_to_use("app/models/valuation/holdings.rb", files)
       end
 
-      attempts = 0
-      begin
-        assert @subject.question_asked?
-      rescue Minitest::Assertion => e
-        raise e if attempts >= 10
-        sleep 0.0001
-        attempts += 1
-      end
-
-      stdin.io = StringIO.new("1\n")
-      th.join
+      wait_until { assert @subject.question_asked? }
 
-      refute @subject.question_asked?
+      stdin.puts("1\n")
       assert_equal "test/models/schedule/holdings_test.rb", th.value
+      refute @subject.question_asked?
     end
 
     def test_read_output

test/test_helper.rb

@@ -1,10 +1,48 @@
 $LOAD_PATH.unshift File.expand_path("../lib", __dir__)
+
 require "retest"
 require "byebug"
 require "minitest/autorun"
 
+WAITING_TIME = 0.0001
+
+def wait(time = WAITING_TIME)
+  sleep time
+end
+
 FakeFS = Struct.new(:files) do
   def exist?(value)
     files.include? value
   end
-end
+end
+
+class BlockingInput
+  attr_accessor :io
+  def initialize
+    @io = StringIO.new
+  end
+
+  def puts(value)
+    @io = StringIO.new(value)
+  end
+
+  def gets
+    loop do
+      wait
+      line = @io.gets.to_s
+      break line unless line.empty?
+    end
+  end
+end
+
+def wait_until(max_attempts: 10)
+  attempts = 0
+  begin
+    yield
+  rescue Minitest::Assertion => e
+    raise e if attempts >= max_attempts
+    wait
+    attempts += 1
+  end
+end
+