test(in_exec): add test cases for command_timeout option

Signed-off-by: zoklk <bjincheol34@gmail.com>

Author: zoklk

test/plugin/test_in_exec.rb

@@ -295,4 +295,47 @@ def create_driver(conf)
       assert_match(/LoadError/, event[2]['message'])
     end
   end
+  sub_test_case 'command_timeout' do
+    test 'configure command_timeout' do
+      d = create_driver %[
+        command ruby -e "sleep 10"
+        tag test
+        run_interval 1s
+        command_timeout 1s
+        <parse>
+          @type none
+        </parse>
+      ]
+      assert_equal 1.0, d.instance.command_timeout
+    end
+
+    test 'command_timeout kills long-running child process' do
+      d = create_driver %[
+        command ruby -e "sleep 10"
+        tag test
+        run_interval 5s
+        command_timeout 1s
+        <parse>
+          @type none
+        </parse>
+      ]
+      start_time = Time.now
+      d.run(timeout: 3)
+      elapsed = Time.now - start_time
+
+      assert elapsed < 4, "command should have been killed by command_timeout"
+    end
+
+    test 'command_timeout defaults to nil' do
+      d = create_driver %[
+        command ruby -e "puts 'hello'"
+        tag test
+        run_interval 1s
+        <parse>
+          @type none
+        </parse>
+      ]
+      assert_nil d.instance.command_timeout
+    end
+  end
 end