1 files changed, 51 insertions, 0 deletions
diff --git a/test/ruby/test_trace.rb b/test/ruby/test_trace.rb
new file mode 100644
index 0000000000..5842f11aee
--- /dev/null
+++ b/test/ruby/test_trace.rb
@@ -0,0 +1,51 @@
+# frozen_string_literal: false
+require 'test/unit'
+
+class TestTrace < Test::Unit::TestCase
+  def test_trace
+    $x = 1234
+    $y = 0
+    trace_var :$x, proc{$y = $x}
+    $x = 40414
+    assert_equal($x, $y)
+
+    untrace_var :$x
+    $x = 19660208
+    assert_not_equal($x, $y)
+
+    trace_var :$x, proc{$x *= 2}
+    $x = 5
+    assert_equal(10, $x)
+
+    untrace_var :$x
+  end
+
+  def test_trace_proc_that_raises_exception
+    $x = 1234
+    trace_var :$x, proc { raise }
+    assert_raise(RuntimeError) { $x = 42 }
+  ensure
+    untrace_var :$x
+  end
+
+  def test_trace_string
+    $x = 1234
+    trace_var :$x, "$y = :bar"
+    $x = 42
+    assert_equal(:bar, $y)
+  ensure
+    untrace_var :$x
+  end
+
+  def test_trace_break
+    bug2722 = '[ruby-core:31783]'
+    a = Object.new.extend(Enumerable)
+    def a.each
+      yield
+    end
+    assert(Thread.start {
+             Thread.current.add_trace_func(proc{})
+             a.any? {true}
+           }.value, bug2722)
+  end
+end