tests demonstrating problems with standard lib Timeout

test/test_timeout.rb

@@ -3,6 +3,9 @@
 require 'thread'
 
 class TestTimeout < Test::Unit::TestCase
+
+  ### Tests that come with standard lib
+
   def test_queue
     q = Queue.new
     assert_raise(Timeout::Error, "[ruby-dev:32935]") {
@@ -29,4 +32,146 @@ def test_cannot_convert_into_time_interval
     def (n = Object.new).zero?; false; end
     assert_raise(TypeError, bug3168) {Timeout.timeout(n) { sleep 0.1 }}
   end
+
+
+  ### tests not included in standard lib, but which standard lib does pass
+
+  def test_non_timing_out_code_is_successful
+    assert_nothing_raised do
+      Timeout.timeout(2) {
+        true
+      }
+    end
+  end
+
+  def test_code_that_takes_too_long_is_stopped_and_raises
+    assert_raise(Timeout::Error) do
+      Timeout.timeout(0.1) {
+        sleep 10
+      }
+    end
+  end
+
+  def test_returns_block_value_when_not_timing_out
+    retval = Timeout.timeout(1){ "foobar" }
+    assert_equal "foobar", retval
+  end
+
+
+  ### Tests demonstrating problems with standard lib
+  # NOTE: this demonstration was done such that all of the assertions pass,
+  #       The ones marked weird, bad, and very bad should not, and their
+  #       passing is demonstrating the brokenness.
+
+  def subject(throws, catches)
+    $inner_attempted=nil
+    $inner_succeeded=nil
+    $caught_in_inner=nil
+
+    $raised_in_outer=nil
+    $not_raised_in_outer=nil
+    begin
+      Timeout.timeout(0.1, throws){
+        begin
+          $inner_attempted=true
+          sleep 10
+        rescue catches
+          $caught_in_inner=true
+        else
+          $inner_succeeded=true
+        end
+      }
+    rescue Exception
+      $raised_in_outer = true
+    else
+      $not_raised_in_outer = true
+    end
+  end
+
+  puts "when an exception to raise is not specified and the inner code does not catch Exception"
+  def test_1
+    subject(nil, StandardError)
+
+    # EXPECTED
+    assert $inner_attempted
+    assert !$inner_succeeded
+    assert !$caught_in_inner
+    assert $raised_in_outer && !$not_raised_in_outer
+  end
+
+  puts "when an exception to raise is not specified and the inner code does catch Exception"
+  def test_2
+    subject(nil, Exception)
+
+    # EXPECTED
+    assert $inner_attempted
+    assert !$inner_succeeded
+
+    # WEIRD
+    assert $caught_in_inner
+
+    # BAD
+    assert !$raised_in_outer && $not_raised_in_outer
+  end
+
+  puts "when an exception to raise is StandardError and the inner code does not catch Exception"
+  class MyError < StandardError; end
+  def test_3
+    subject(MyError, StandardError)
+
+    # EXPECTED
+    assert $inner_attempted
+    assert !$inner_succeeded
+
+    # WEIRD
+    assert $caught_in_inner
+
+    # BAD
+    assert !$raised_in_outer && $not_raised_in_outer
+  end
+
+  puts "when an exception to raise is StandardError and the inner code does catch Exception"
+  class MyError2 < StandardError; end
+  def test_4
+    subject(MyError2, Exception)
+
+    # EXPECTED
+    assert $inner_attempted
+    assert !$inner_succeeded
+
+    # WEIRD
+    assert $caught_in_inner
+
+    # BAD
+    assert !$raised_in_outer && $not_raised_in_outer
+  end
+
+  puts "when an exception to raise is Exception and the inner code does not catch Exception"
+  class MyError3 < Exception; end
+  def test_5
+    subject(MyError3, StandardError)
+
+    # EXPECTED
+    assert $inner_attempted
+    assert !$inner_succeeded
+    assert !$caught_in_inner
+    assert $raised_in_outer && !$not_raised_in_outer
+  end
+
+  puts "when an exception to raise is Exception and the inner code does catch Exception"
+  class MyError4 < Exception; end
+  def test_6
+    subject(MyError4, Exception)
+
+    # EXPECTED
+    assert $inner_attempted
+    assert !$inner_succeeded
+
+    # WEIRD
+    assert $caught_in_inner
+
+    # VERY BAD
+    assert !$raised_in_outer && $not_raised_in_outer
+  end
+
 end