diff --git a/testsrc/de/steamwar/AssertionUtils.java b/testsrc/de/steamwar/AssertionUtils.java
new file mode 100644
index 0000000..58fe01c
--- /dev/null
+++ b/testsrc/de/steamwar/AssertionUtils.java
@@ -0,0 +1,26 @@
+package de.steamwar;
+
+import de.steamwar.command.CommandFrameworkException;
+import lombok.experimental.UtilityClass;
+
+import java.util.List;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.*;
+
+@UtilityClass
+public class AssertionUtils {
+
+    public static void assertCMDFramework(Exception e, Class<?> clazz, String message) {
+        assertThat(e, is(instanceOf(CommandFrameworkException.class)));
+        assertThat(e.getCause().getCause(), is(instanceOf(clazz)));
+        assertThat(e.getCause().getCause().getMessage(), is(message));
+    }
+
+    public static <T> void assertTabCompletes(List<T> list, T... elements) {
+        assertThat(list.size(), is(elements.length));
+        if (elements.length > 0) {
+            assertThat(list, containsInAnyOrder(elements));
+        }
+    }
+}
diff --git a/testsrc/de/steamwar/command/ArgumentCommandTest.java b/testsrc/de/steamwar/command/ArgumentCommandTest.java
index d7a24f1..7b74126 100644
--- a/testsrc/de/steamwar/command/ArgumentCommandTest.java
+++ b/testsrc/de/steamwar/command/ArgumentCommandTest.java
@@ -3,9 +3,10 @@ package de.steamwar.command;
 import de.steamwar.command.dto.ExecutionIdentifier;
 import org.junit.Test;
 
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.instanceOf;
-import static org.hamcrest.Matchers.is;
+import java.util.List;
+
+import static de.steamwar.AssertionUtils.assertCMDFramework;
+import static de.steamwar.AssertionUtils.assertTabCompletes;
 
 public class ArgumentCommandTest {
 
@@ -25,8 +26,7 @@ public class ArgumentCommandTest {
         try {
             cmd.execute("test", "", new String[]{"true", "false"});
         } catch (Exception e) {
-            assertThat(e.getCause().getCause(), is(instanceOf(ExecutionIdentifier.class)));
-            assertThat(e.getCause().getCause().getMessage(), is("RunArgument with Boolean"));
+            assertCMDFramework(e, ExecutionIdentifier.class, "RunArgument with Boolean");
         }
     }
 
@@ -36,8 +36,7 @@ public class ArgumentCommandTest {
         try {
             cmd.execute("test", "", new String[]{"0.0", "0.0", "0.0"});
         } catch (Exception e) {
-            assertThat(e.getCause().getCause(), is(instanceOf(ExecutionIdentifier.class)));
-            assertThat(e.getCause().getCause().getMessage(), is("RunArgument with Float"));
+            assertCMDFramework(e, ExecutionIdentifier.class, "RunArgument with Float");
         }
     }
 
@@ -47,8 +46,7 @@ public class ArgumentCommandTest {
         try {
             cmd.execute("test", "", new String[]{"0.0", "0.0"});
         } catch (Exception e) {
-            assertThat(e.getCause().getCause(), is(instanceOf(ExecutionIdentifier.class)));
-            assertThat(e.getCause().getCause().getMessage(), is("RunArgument with Double"));
+            assertCMDFramework(e, ExecutionIdentifier.class, "RunArgument with Double");
         }
     }
 
@@ -58,8 +56,7 @@ public class ArgumentCommandTest {
         try {
             cmd.execute("test", "", new String[]{"0"});
         } catch (Exception e) {
-            assertThat(e.getCause().getCause(), is(instanceOf(ExecutionIdentifier.class)));
-            assertThat(e.getCause().getCause().getMessage(), is("RunArgument with Integer"));
+            assertCMDFramework(e, ExecutionIdentifier.class, "RunArgument with Integer");
         }
     }
 
@@ -69,8 +66,7 @@ public class ArgumentCommandTest {
         try {
             cmd.execute("test", "", new String[]{"0", "0"});
         } catch (Exception e) {
-            assertThat(e.getCause().getCause(), is(instanceOf(ExecutionIdentifier.class)));
-            assertThat(e.getCause().getCause().getMessage(), is("RunArgument with Long"));
+            assertCMDFramework(e, ExecutionIdentifier.class, "RunArgument with Long");
         }
     }
 
@@ -80,8 +76,21 @@ public class ArgumentCommandTest {
         try {
             cmd.execute("test", "", new String[]{"Hello World"});
         } catch (Exception e) {
-            assertThat(e.getCause().getCause(), is(instanceOf(ExecutionIdentifier.class)));
-            assertThat(e.getCause().getCause().getMessage(), is("RunArgument with String"));
+            assertCMDFramework(e, ExecutionIdentifier.class, "RunArgument with String");
         }
     }
+
+    @Test
+    public void testTabComplete() {
+        ArgumentCommand cmd = new ArgumentCommand();
+        List<String> strings = cmd.tabComplete("test", "", new String[]{""});
+        assertTabCompletes(strings, "true", "false");
+    }
+
+    @Test
+    public void testPartialTabComplete() {
+        ArgumentCommand cmd = new ArgumentCommand();
+        List<String> strings = cmd.tabComplete("test", "", new String[]{"t"});
+        assertTabCompletes(strings, "true", "t");
+    }
 }
diff --git a/testsrc/de/steamwar/command/SimpleCommandTest.java b/testsrc/de/steamwar/command/SimpleCommandTest.java
index a039e75..4ba3ef1 100644
--- a/testsrc/de/steamwar/command/SimpleCommandTest.java
+++ b/testsrc/de/steamwar/command/SimpleCommandTest.java
@@ -3,9 +3,10 @@ package de.steamwar.command;
 import de.steamwar.command.dto.ExecutionIdentifier;
 import org.junit.Test;
 
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.instanceOf;
-import static org.hamcrest.Matchers.is;
+import java.util.List;
+
+import static de.steamwar.AssertionUtils.assertCMDFramework;
+import static de.steamwar.AssertionUtils.assertTabCompletes;
 
 public class SimpleCommandTest {
 
@@ -14,9 +15,8 @@ public class SimpleCommandTest {
         SimpleCommand cmd = new SimpleCommand();
         try {
             cmd.execute("test", "", new String[0]);
-        } catch (CommandFrameworkException e) {
-            assertThat(e.getCause().getCause(), is(instanceOf(ExecutionIdentifier.class)));
-            assertThat(e.getCause().getCause().getMessage(), is("RunSimple with noArgs"));
+        } catch (Exception e) {
+            assertCMDFramework(e, ExecutionIdentifier.class, "RunSimple with noArgs");
         }
     }
 
@@ -29,4 +29,11 @@ public class SimpleCommandTest {
             throw new AssertionError("No exception expected");
         }
     }
+
+    @Test
+    public void testSimpleTabComplete() {
+        SimpleCommand cmd = new SimpleCommand();
+        List<String> strings = cmd.tabComplete("test", "", new String[]{""});
+        assertTabCompletes(strings);
+    }
 }