diff --git a/RecrownedGTK.Tools.Tests/CommandProcessor/EngineCommandTest.cs b/RecrownedGTK.Tools.Tests/CommandProcessor/EngineCommandTest.cs
new file mode 100644
index 0000000..e02176b
--- /dev/null
+++ b/RecrownedGTK.Tools.Tests/CommandProcessor/EngineCommandTest.cs
@@ -0,0 +1,145 @@
+using System;
+using RecrownedGTK.Tools.CommandProcessor;
+using NUnit.Framework;
+
+namespace RecrownedGTK.Tools.Tests.CommandProcessor {
+    public class EngineCommandTest {
+        string[] fakeArguments;
+        DummyInput dummyInput;
+        DummyOutput dummyOutput;
+        DummyCommand dummyCommand;
+        EngineCommandArgument dummyCommandArgument;
+        private class DummyInput : IUserInput {
+            public string dummyInput;
+            public string GetInput() {
+                return dummyInput;
+            }
+        }
+
+        private class DummyOutput : IUserOutput
+        {
+            public bool cleared;
+            public string output;
+            public string wrappedOutput;
+            public void ClearOutput()
+            {
+                cleared = true;
+            }
+
+            public void Output(string output)
+            {
+                this.output = output;
+            }
+
+            public void WrappedOutput(string output)
+            {
+                this.wrappedOutput = output;
+            }
+        }
+
+        private class DummyCommand : EngineCommand
+        {
+            public DummyCommand(string invoker, params EngineCommandArgument[] engineCommandArguments) : base("helped", invoker) {
+                this.commandArguments = engineCommandArguments;
+            }
+
+            public override void Run(IUserInput userInput, IUserOutput userOutput, params string[] arguments)
+            {
+                if (arguments != null && arguments[0] != null) {
+                    userOutput.Output(arguments[0] + " argument");
+                } else {
+                    userOutput.Output(userInput.GetInput() + " input");
+                }
+
+
+            }
+        }
+
+        [SetUp]
+        public void Setup()
+        {
+            dummyInput = new DummyInput();
+            dummyOutput = new DummyOutput();
+            dummyCommandArgument = new EngineCommandArgument("arg", "arg help", false);
+            dummyCommand = new DummyCommand("invoke", dummyCommandArgument);
+        }
+
+        [OneTimeSetUp]
+        public void InitialSetup() {
+            fakeArguments = new string[] {"fake1", "fake2", "fake3", "fake4", "fake5", "fake6", "arg"};
+        }
+
+        [Test]
+        public void RunTestNoArguments() {
+            dummyInput.dummyInput = "input";
+            dummyCommand.Run(dummyInput, dummyOutput, null);
+            Assert.AreEqual(dummyOutput.output, "input input");
+        }
+
+        [Test]
+        public void RunTestWithArguments() {
+            dummyCommand.Run(dummyInput, dummyOutput, "args");
+            Assert.AreEqual(dummyOutput.output, "args argument");
+        }
+
+        public void EngineCommandArgumentOfTestValid() {
+            Assert.AreEqual(dummyCommandArgument, dummyCommand.EngineCommandArgumentOf("args"));
+        }
+
+        public void EngineCommandArgumentOfTestNull() {
+            Assert.IsNull(dummyCommand.EngineCommandArgumentOf("nothing here"));
+        }
+
+        [Test]
+        public void ValidateTestFalse() {
+            Assert.IsFalse(dummyCommand.Validate("notexisting"));
+        }
+
+        [Test]
+        public void ValidateTestTrue() {
+            Assert.IsTrue(dummyCommand.Validate("arg"));
+        }
+
+        [Test]
+        public void IndexOfArgumentTestInvald() {
+            try {
+                EngineCommand.IndexOfArgument("fake argument", new string[] {"argument", "argument_again"});
+            } catch (ArgumentException) {
+                Assert.Pass();
+            }
+            Assert.Fail();
+        }
+
+        [TestCase("fake1", 0)]
+        [TestCase("fake3", 2)]
+        [TestCase("fake6", 5)]
+        [TestCase("arg", 6)]
+        public void IndexOfArgumentTestValidWithString(string argument, int expected) {
+            Assert.AreEqual(EngineCommand.IndexOfArgument(argument, this.fakeArguments), expected);
+        }
+
+        [Test]
+        public void IndexOfArgumentTestValidWithObject() {
+            Assert.AreEqual(6, EngineCommand.IndexOfArgument(dummyCommandArgument, fakeArguments));
+        }
+
+        [TestCase("fake1", true)]
+        [TestCase("fake3", true)]
+        [TestCase("arg", true)]
+        [TestCase("fake8", false)]
+        public void HasArgumentTest(string argument, bool expected) {
+            Assert.AreEqual(EngineCommand.HasArgument(argument, fakeArguments), expected);
+        }
+
+        [Test]
+        public void HelpTestNoArgument() {
+            string expected = "helped\r\nPossible arguments: arg. (* are required arguments.)\r\n";
+            Assert.AreEqual(expected, dummyCommand.Help());
+        }
+
+        [Test]
+        public void HelpTestArgument() {
+            Assert.AreEqual(dummyCommand.Help("arg"), "arg help");
+        }
+    }
+}
\ No newline at end of file