Set help command to short description and alternatives

- As discussed in https://github.com/AuthMe/AuthMeReloaded/pull/169

src/main/java/fr/xephi/authme/command/executable/HelpCommand.java

@@ -14,6 +14,11 @@ import java.util.List;
 
 import static fr.xephi.authme.command.FoundResultStatus.MISSING_BASE_COMMAND;
 import static fr.xephi.authme.command.FoundResultStatus.UNKNOWN_LABEL;
+import static fr.xephi.authme.command.help.HelpProvider.ALL_OPTIONS;
+import static fr.xephi.authme.command.help.HelpProvider.SHOW_ALTERNATIVES;
+import static fr.xephi.authme.command.help.HelpProvider.SHOW_CHILDREN;
+import static fr.xephi.authme.command.help.HelpProvider.SHOW_COMMAND;
+import static fr.xephi.authme.command.help.HelpProvider.SHOW_DESCRIPTION;
 
 public class HelpCommand implements ExecutableCommand {
 
@@ -46,9 +51,9 @@ public class HelpCommand implements ExecutableCommand {
 
         int mappedCommandLevel = result.getCommandDescription().getLabelCount();
         if (mappedCommandLevel == 1) {
-            helpProvider.outputHelp(sender, result, HelpProvider.SHOW_CHILDREN);
+            helpProvider.outputHelp(sender, result, SHOW_COMMAND | SHOW_DESCRIPTION | SHOW_CHILDREN | SHOW_ALTERNATIVES);
         } else {
-            helpProvider.outputHelp(sender, result, HelpProvider.ALL_OPTIONS);
+            helpProvider.outputHelp(sender, result, ALL_OPTIONS);
         }
     }
 

src/main/java/fr/xephi/authme/command/help/HelpProvider.java

@@ -15,11 +15,12 @@ import org.bukkit.command.CommandSender;
 
 import javax.inject.Inject;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
+import java.util.function.Function;
 
 import static fr.xephi.authme.command.help.HelpSection.DETAILED_DESCRIPTION;
 import static fr.xephi.authme.command.help.HelpSection.SHORT_DESCRIPTION;
-import static java.util.Arrays.asList;
 import static java.util.Collections.singletonList;
 
 /**
@@ -171,19 +172,29 @@ public class HelpProvider implements Reloadable {
     }
 
     private void printAlternatives(CommandDescription command, List<String> correctLabels, List<String> lines) {
-        if (command.getLabels().size() <= 1 || correctLabels.size() <= 1) {
+        if (command.getLabels().size() <= 1) {
             return;
         }
 
         lines.add(ChatColor.GOLD + helpMessagesService.getMessage(HelpSection.ALTERNATIVES) + ":");
-        // Get the label used
+
-        final String parentLabel = correctLabels.get(0);
+        // Label with which the command was called -> don't show it as an alternative
-        final String childLabel = correctLabels.get(1);
+        final String usedLabel;
+        // Takes alternative label and constructs list of labels, e.g. "reg" -> [authme, reg]
+        final Function<String, List<String>> commandLabelsFn;
+
+        if (correctLabels.size() == 1) {
+            usedLabel = correctLabels.get(0);
+            commandLabelsFn = label -> singletonList(label);
+        } else {
+            usedLabel = correctLabels.get(1);
+            commandLabelsFn = label -> Arrays.asList(correctLabels.get(0), label);
+        }
 
         // Create a list of alternatives
-        for (String entry : command.getLabels()) {
+        for (String label : command.getLabels()) {
-            if (!entry.equalsIgnoreCase(childLabel)) {
+            if (!label.equalsIgnoreCase(usedLabel)) {
-                lines.add(" " + CommandSyntaxHelper.getSyntax(command, asList(parentLabel, entry)));
+                lines.add(" " + CommandSyntaxHelper.getSyntax(command, commandLabelsFn.apply(label)));
             }
         }
     }

src/test/java/fr/xephi/authme/command/executable/HelpCommandTest.java

@@ -20,6 +20,10 @@ import static fr.xephi.authme.command.FoundResultStatus.INCORRECT_ARGUMENTS;
 import static fr.xephi.authme.command.FoundResultStatus.MISSING_BASE_COMMAND;
 import static fr.xephi.authme.command.FoundResultStatus.SUCCESS;
 import static fr.xephi.authme.command.FoundResultStatus.UNKNOWN_LABEL;
+import static fr.xephi.authme.command.help.HelpProvider.SHOW_ALTERNATIVES;
+import static fr.xephi.authme.command.help.HelpProvider.SHOW_CHILDREN;
+import static fr.xephi.authme.command.help.HelpProvider.SHOW_COMMAND;
+import static fr.xephi.authme.command.help.HelpProvider.SHOW_DESCRIPTION;
 import static java.util.Arrays.asList;
 import static java.util.Collections.singletonList;
 import static org.hamcrest.CoreMatchers.containsString;
@@ -108,7 +112,7 @@ public class HelpCommandTest {
         CommandDescription commandDescription = mock(CommandDescription.class);
         given(commandDescription.getLabelCount()).willReturn(1);
         FoundCommandResult foundCommandResult = new FoundCommandResult(commandDescription, singletonList("authme"),
-            Collections.<String>emptyList(), 0.0, SUCCESS);
+            Collections.emptyList(), 0.0, SUCCESS);
         given(commandMapper.mapPartsToCommand(sender, arguments)).willReturn(foundCommandResult);
 
         // when
@@ -116,7 +120,8 @@ public class HelpCommandTest {
 
         // then
         verify(sender, never()).sendMessage(anyString());
-        verify(helpProvider).outputHelp(sender, foundCommandResult, HelpProvider.SHOW_CHILDREN);
+        verify(helpProvider).outputHelp(sender, foundCommandResult,
+            SHOW_DESCRIPTION | SHOW_COMMAND | SHOW_CHILDREN | SHOW_ALTERNATIVES);
     }
 
     @Test
@@ -126,7 +131,7 @@ public class HelpCommandTest {
         CommandDescription commandDescription = mock(CommandDescription.class);
         given(commandDescription.getLabelCount()).willReturn(2);
         FoundCommandResult foundCommandResult = new FoundCommandResult(commandDescription, asList("authme", "getpos"),
-            Collections.<String>emptyList(), 0.0, INCORRECT_ARGUMENTS);
+            Collections.emptyList(), 0.0, INCORRECT_ARGUMENTS);
         given(commandMapper.mapPartsToCommand(sender, arguments)).willReturn(foundCommandResult);
 
         // when

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

@@ -395,6 +395,24 @@ public class HelpProviderTest {
         assertThat(lines.get(0), equalTo("Command: /authme register <password> <confirmation>"));
     }
 
+    @Test
+    public void shouldShowAlternativesForRootCommand() {
+        // given
+        CommandDescription command = getCommandWithLabel(commands, "unregister");
+        FoundCommandResult result = newFoundResult(command, Collections.singletonList("unreg"));
+
+        // when
+        helpProvider.outputHelp(sender, result, SHOW_COMMAND | SHOW_ALTERNATIVES);
+
+        // then
+        List<String> lines = getLines(sender);
+        assertThat(lines, hasSize(4));
+        assertThat(lines.get(0), equalTo("Header"));
+        assertThat(lines.get(1), equalTo("Command: /unreg <player>"));
+        assertThat(lines.get(2), equalTo("Alternatives:"));
+        assertThat(lines.get(3), equalTo(" /unregister <player>"));
+    }
+
     /**
      * Generate an instance of {@link FoundCommandResult} with the given command and labels. All other fields aren't
      * retrieved by {@link HelpProvider} and so are initialized to default values for the tests.