1 files changed, 81 insertions, 0 deletions
diff --git a/spec/ruby/core/process/detach_spec.rb b/spec/ruby/core/process/detach_spec.rb
new file mode 100644
index 0000000000..33c674394e
--- /dev/null
+++ b/spec/ruby/core/process/detach_spec.rb
@@ -0,0 +1,81 @@
+require_relative '../../spec_helper'
+
+describe "Process.detach" do
+  platform_is_not :windows do
+    it "returns a thread" do
+      pid = Process.fork { Process.exit! }
+      thr = Process.detach(pid)
+      thr.should.is_a?(Thread)
+      thr.join
+    end
+
+    it "produces the exit Process::Status as the thread value" do
+      pid = Process.fork { Process.exit! }
+      thr = Process.detach(pid)
+      thr.join
+
+      status = thr.value
+      status.should.is_a?(Process::Status)
+      status.pid.should == pid
+    end
+
+    platform_is_not :openbsd do
+      it "reaps the child process's status automatically" do
+        pid = Process.fork { Process.exit! }
+        Process.detach(pid).join
+        -> { Process.waitpid(pid) }.should.raise(Errno::ECHILD)
+      end
+    end
+
+    it "sets the :pid thread-local to the PID" do
+      pid = Process.fork { Process.exit! }
+      thr = Process.detach(pid)
+      thr.join
+
+      thr[:pid].should == pid
+    end
+
+    it "provides a #pid method on the returned thread which returns the PID" do
+      pid = Process.fork { Process.exit! }
+      thr = Process.detach(pid)
+      thr.join
+
+      thr.pid.should == pid
+    end
+
+    it "tolerates not existing child process pid" do
+      # Use a value that is close to the INT_MAX (pid usually is signed int).
+      # It should (at least) be greater than allowed pid limit value that depends on OS.
+      pid_not_existing = 2.pow(30)
+
+      # Check that there is no a child process with this hardcoded pid.
+      # Command `kill 0 pid`:
+      # - returns "1" if a process exists and
+      # - raises Errno::ESRCH otherwise
+      -> {  Process.kill(0, pid_not_existing) }.should.raise(Errno::ESRCH)
+
+      thr = Process.detach(pid_not_existing)
+      thr.join
+
+      thr.should.is_a?(Thread)
+    end
+
+    it "calls #to_int to implicitly convert non-Integer pid to Integer" do
+      pid = MockObject.new('mock-enumerable')
+      pid.should_receive(:to_int).and_return(100500)
+
+      Process.detach(pid).join
+    end
+
+    it "raises TypeError when pid argument does not have #to_int method" do
+      -> { Process.detach(Object.new) }.should.raise(TypeError, "no implicit conversion of Object into Integer")
+    end
+
+    it "raises TypeError when #to_int returns non-Integer value" do
+      pid = MockObject.new('mock-enumerable')
+      pid.should_receive(:to_int).and_return(:symbol)
+
+      -> { Process.detach(pid) }.should raise_consistent_error(TypeError, "can't convert MockObject into Integer (MockObject#to_int gives Symbol)")
+    end
+  end
+end