1 files changed, 75 insertions, 0 deletions
diff --git a/test/ruby/test_flip.rb b/test/ruby/test_flip.rb
new file mode 100644
index 0000000000..9c58f5f497
--- /dev/null
+++ b/test/ruby/test_flip.rb
@@ -0,0 +1,75 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class TestFlip < Test::Unit::TestCase
+  def test_flip_flop
+    assert_equal [4,5], (1..9).select {|n| true if (n==4)..(n==5)}
+    assert_equal [4,5], (1..9).select {|n| true if (n==4)...(n==5)}
+    assert_equal [2], (1..9).select {|n| true if (n==2)..(n%2).zero?}
+    assert_equal [2,3,4], (1..9).select {|n| true if (n==2)...(n%2).zero?}
+    assert_equal [4,5,7,8], (1..9).select {|n| true if (n==4)...(n==5) or (n==7)...(n==8)}
+    assert_equal [nil, 2, 3, 4, nil], (1..5).map {|x| x if (x==2..x==4)}
+    assert_equal [1, nil, nil, nil, 5], (1..5).map {|x| x if !(x==2..x==4)}
+  end
+
+  def test_hidden_key
+    bug6899 = '[ruby-core:47253]'
+    foo = "foor"
+    bar = "bar"
+    assert_nothing_raised(NotImplementedError, bug6899) do
+      2000.times {eval %[(foo..bar) ? 1 : 2]}
+    end
+    [foo, bar]
+  end
+
+  def test_shared_eval
+    bug7671 = '[ruby-core:51296]'
+    vs = (1..9).to_a
+    vs.select {|n| if n==2..n==16 then 1 end}
+    v = eval("vs.select {|n| if n==3..n==6 then 1 end}")
+    assert_equal([*3..6], v, bug7671)
+    vs
+  end
+
+  def test_shared_thread
+    ff = proc {|n| true if n==3..n==5}
+    v = 1..9
+    a = true
+    th = Thread.new {
+      v.select {|i|
+        Thread.pass while a
+        ff[i].tap {a = true}
+      }
+    }
+    v1 = v.select {|i|
+      Thread.pass until a
+      ff[i].tap {a = false}
+    }
+    v2 = th.value
+    expected = [3, 4, 5]
+    mesg = 'flip-flop should be separated per threads'
+    assert_equal(expected, v1, mesg)
+    assert_equal(expected, v2, mesg)
+  end
+
+  def test_input_line_number_range
+    bug12947 = '[ruby-core:78162] [Bug #12947]'
+    ary = b1 = b2 = nil
+    EnvUtil.suppress_warning do
+      b1 = eval("proc {|i| i if 2..4}")
+      b2 = eval("proc {|i| if 2..4; i; end}")
+    end
+    IO.pipe {|r, w|
+      th = Thread.start {(1..5).each {|i| w.puts i};w.close}
+      ary = r.map {|i| b1.call(i.chomp)}
+      th.join
+    }
+    assert_equal([nil, "2", "3", "4", nil], ary, bug12947)
+    IO.pipe {|r, w|
+      th = Thread.start {(1..5).each {|i| w.puts i};w.close}
+      ary = r.map {|i| b2.call(i.chomp)}
+      th.join
+    }
+    assert_equal([nil, "2", "3", "4", nil], ary, bug12947)
+  end
+end