#305 Adjust behavior of label handling; cleanup

- Fix bugs in behavior (wrong labels being shown for help)
- Change order of labels and arguments in FoundCommandResult constructors
- Move FoundResultStatus enum to its own class
- Create test class for HelpProvider

src/test/java/fr/xephi/authme/command/help/HelpProviderTest.java

@@ -0,0 +1,65 @@
+package fr.xephi.authme.command.help;
+
+import fr.xephi.authme.command.CommandDescription;
+import fr.xephi.authme.command.ExecutableCommand;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.hamcrest.Matchers.contains;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Test for {@link HelpProvider}.
+ */
+public class HelpProviderTest {
+
+    private static CommandDescription parent;
+    private static CommandDescription child;
+
+    @BeforeClass
+    public static void setUpCommands() {
+        parent = CommandDescription.builder()
+            .executableCommand(mock(ExecutableCommand.class))
+            .labels("base", "b")
+            .description("Parent")
+            .detailedDescription("Test base command.")
+            .build();
+        child = CommandDescription.builder()
+            .executableCommand(mock(ExecutableCommand.class))
+            .parent(parent)
+            .labels("child", "c")
+            .description("Child")
+            .detailedDescription("Child test command.")
+            .withArgument("Argument", "The argument", false)
+            .build();
+    }
+
+    @Test
+    public void shouldRetainCorrectLabels() {
+        // given
+        List<String> labels = Arrays.asList("b", "child");
+
+        // when
+        List<String> result = HelpProvider.filterCorrectLabels(child, labels);
+
+        // then
+        assertThat(result, contains("b", "child"));
+    }
+
+    @Test
+    public void shouldReplaceIncorrectLabels() {
+        // given
+        List<String> labels = Arrays.asList("base", "wrong");
+
+        // when
+        List<String> result = HelpProvider.filterCorrectLabels(child, labels);
+
+        // then
+        assertThat(result, contains("base", "child"));
+    }
+
+}