1 files changed, 102 insertions, 0 deletions
diff --git a/spec/ruby/core/thread/report_on_exception_spec.rb b/spec/ruby/core/thread/report_on_exception_spec.rb
new file mode 100644
index 0000000000..4128dad470
--- /dev/null
+++ b/spec/ruby/core/thread/report_on_exception_spec.rb
@@ -0,0 +1,102 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+
+ruby_version_is "2.4" do
+  describe "Thread.report_on_exception" do
+    it "defaults to false" do
+      ruby_exe("p Thread.report_on_exception").should == "false\n"
+    end
+  end
+
+  describe "Thread.report_on_exception=" do
+    before :each do
+      @report_on_exception = Thread.report_on_exception
+    end
+
+    after :each do
+      Thread.report_on_exception = @report_on_exception
+    end
+
+    it "changes the default value for new threads" do
+      Thread.report_on_exception = true
+      Thread.report_on_exception.should == true
+      t = Thread.new {}
+      t.join
+      t.report_on_exception.should == true
+    end
+  end
+
+  describe "Thread#report_on_exception" do
+    it "returns whether the Thread will print a backtrace if it exits with an exception" do
+      t = Thread.new { Thread.current.report_on_exception = true }
+      t.join
+      t.report_on_exception.should == true
+
+      t = Thread.new { Thread.current.report_on_exception = false }
+      t.join
+      t.report_on_exception.should == false
+    end
+  end
+
+  describe "Thread#report_on_exception=" do
+    describe "when set to true" do
+      it "prints a backtrace on $stderr if it terminates with an exception" do
+        t = nil
+        -> {
+          t = Thread.new {
+            Thread.current.report_on_exception = true
+            raise RuntimeError, "Thread#report_on_exception specs"
+          }
+          Thread.pass while t.alive?
+        }.should output("", /Thread.+terminated with exception.+Thread#report_on_exception specs/m)
+
+        -> {
+          t.join
+        }.should raise_error(RuntimeError, "Thread#report_on_exception specs")
+      end
+    end
+
+    describe "when set to false" do
+      it "lets the thread terminates silently with an exception" do
+        t = nil
+        -> {
+          t = Thread.new {
+            Thread.current.report_on_exception = false
+            raise RuntimeError, "Thread#report_on_exception specs"
+          }
+          Thread.pass while t.alive?
+        }.should output("", "")
+
+        -> {
+          t.join
+        }.should raise_error(RuntimeError, "Thread#report_on_exception specs")
+      end
+    end
+
+    ruby_bug "#13163", "2.4"..."2.5" do
+      describe "when used in conjunction with Thread#abort_on_exception" do
+        it "first reports then send the exception back to the main Thread" do
+          t = nil
+          mutex = Mutex.new
+          mutex.lock
+          -> {
+            t = Thread.new {
+              Thread.current.abort_on_exception = true
+              Thread.current.report_on_exception = true
+              mutex.lock
+              mutex.unlock
+              raise RuntimeError, "Thread#report_on_exception specs"
+            }
+
+            -> {
+              mutex.sleep(5)
+            }.should raise_error(RuntimeError, "Thread#report_on_exception specs")
+          }.should output("", /Thread.+terminated with exception.+Thread#report_on_exception specs/m)
+
+          -> {
+            t.join
+          }.should raise_error(RuntimeError, "Thread#report_on_exception specs")
+        end
+      end
+    end
+  end
+end