[#678][#575] Use mixinStandardHelpOptions in AutoComplete$App (add …

…the `--version` option); add Exit Status section in usage help message.

Closes #678
Closes #575

RELEASE-NOTES.md

@@ -162,6 +162,7 @@ With the new execute API the ColorScheme class will start to play a more central
 - [#663] How to remove stacktraces on error. Thanks to [Nicolas Mingo](https://github.com/nicolasmingo) and [jrevault](https://github.com/jrevault) for raising this and subsequent discussion.
 - [#672] Need way to send errors back from subcommand. Thanks to [Garret Wilson](https://github.com/garretwilson) for raising this.
 - [#678] Exit Status section in usage help message.
+- [#575] Use mixinStandardHelpOptions in `AutoComplete$App` (add the `--version` option)
 - [#676] Bugfix: non-defined variables in `defaultValue` now correctly resolve to `null`, and options and positional parameters are now correctly considered `required` only if their default value is `null` after variable interpolation. Thanks to [ifedorenko](https://github.com/ifedorenko) for raising this.
 - [#679] Documentation: Update examples for new execute API. Add examples for exit code control and custom exception handlers.
 

src/main/java/picocli/AutoComplete.java

@@ -18,6 +18,7 @@
 import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
+import java.io.PrintWriter;
 import java.io.Writer;
 import java.net.InetAddress;
 import java.util.ArrayList;
@@ -35,6 +36,7 @@
 import picocli.CommandLine.Model.OptionSpec;
 
 import static java.lang.String.*;
+import static picocli.CommandLine.Model.UsageMessageSpec.keyValuesMap;
 
 /**
  * Stand-alone tool that generates bash auto-complete scripts for picocli-based command line applications.
@@ -69,6 +71,14 @@ public int handleExecutionException(Exception ex, CommandLine commandLine, Parse
         };
         int exitCode = new CommandLine(new App())
                 .setExecutionExceptionHandler(errorHandler)
+                .setExitCodeHelpSection("%nExit Codes:%n",
+                        keyValuesMap("0:Successful program execution",
+                                     "1:Usage error: user input for the command was incorrect, " +
+                                             "e.g., the wrong number of arguments, a bad flag, " +
+                                             "a bad syntax in a parameter, etc.",
+                                     "2:The specified command script exists (Specify --force to overwrite).",
+                                     "3:The specified completion script exists (Specify --force to overwrite).",
+                                     "4:An exception occurred while generating the completion script."))
                 .execute(args);
         if ((exitCode == EXIT_CODE_SUCCESS && exitOnSuccess()) || (exitCode != EXIT_CODE_SUCCESS && exitOnError())) {
             System.exit(exitCode);
@@ -91,9 +101,10 @@ private static boolean syspropDefinedAndNotFalse(String key) {
     /**
      * CLI command class for generating completion script.
      */
-    @Command(name = "picocli.AutoComplete", sortOptions = false,
+    @Command(name = "picocli.AutoComplete", mixinStandardHelpOptions = true,
+            version = "picocli.AutoComplete v4.0.0-alpha-3-SNAPSHOT", sortOptions = false,
             description = "Generates a bash completion script for the specified command class.",
-            footerHeading = "%n@|bold Exit Code|@%n",
+            footerHeading = "%n@|bold System Properties:|@%n",
             footer = {"Set the following system properties to control the exit code of this program:",
                     " \"@|yellow picocli.autocomplete.systemExitOnSuccess|@\" - call `System.exit(0)` when",
                     "                                              execution completes normally",
@@ -132,8 +143,7 @@ private static class App implements Callable<Integer> {
         @Option(names = {"-f", "--force"}, description = "Overwrite existing script files.")
         boolean overwriteIfExists;
 
-        @Option(names = { "-h", "--help"}, usageHelp = true, description = "Display this help message and quit.")
-        boolean usageHelpRequested;
+        @Spec CommandSpec spec;
 
         public Integer call() throws Exception {
             IFactory factory = CommandLine.defaultFactory();
@@ -170,8 +180,9 @@ public Integer call() throws Exception {
 
         private boolean checkExists(final File file) {
             if (file.exists()) {
-                System.err.printf("ERROR: picocli.AutoComplete: %s exists. Specify --force to overwrite.%n", file.getAbsolutePath());
-                CommandLine.usage(this, System.err);
+                PrintWriter err = spec.commandLine().getErr();
+                err.printf("ERROR: picocli.AutoComplete: %s exists. Specify --force to overwrite.%n", file.getAbsolutePath());
+                spec.commandLine().usage(err);
                 return true;
             }
             return false;

src/test/java/picocli/AutoCompleteTest.java

@@ -187,7 +187,7 @@ private static String toString(Object obj) {
     }
 
     private static final String AUTO_COMPLETE_APP_USAGE = String.format("" +
-            "Usage: picocli.AutoComplete [-fhw] [-c=<factoryClass>] [-n=<commandName>]%n" +
+            "Usage: picocli.AutoComplete [-fhVw] [-c=<factoryClass>] [-n=<commandName>]%n" +
             "                            [-o=<autoCompleteScript>] <commandLineFQCN>%n" +
             "Generates a bash completion script for the specified command class.%n" +
             "      <commandLineFQCN>      Fully qualified class name of the annotated @Command%n" +
@@ -210,9 +210,18 @@ private static String toString(Object obj) {
             "  -w, --writeCommandScript   Write a '<commandName>' sample command script to the%n" +
             "                               same directory as the completion script.%n" +
             "  -f, --force                Overwrite existing script files.%n" +
-            "  -h, --help                 Display this help message and quit.%n" +
+            "  -h, --help                 Show this help message and exit.%n" +
+            "  -V, --version              Print version information and exit.%n" +
             "%n" +
-            "Exit Code%n" +
+            "Exit Codes:%n" +
+            "  0   Successful program execution%n" +
+            "  1   Usage error: user input for the command was incorrect, e.g., the wrong%n" +
+            "        number of arguments, a bad flag, a bad syntax in a parameter, etc.%n" +
+            "  2   The specified command script exists (Specify --force to overwrite).%n" +
+            "  3   The specified completion script exists (Specify --force to overwrite).%n" +
+            "  4   An exception occurred while generating the completion script.%n" +
+            "%n" +
+            "System Properties:%n" +
             "Set the following system properties to control the exit code of this program:%n" +
             " \"picocli.autocomplete.systemExitOnSuccess\" - call `System.exit(0)` when%n" +
             "                                              execution completes normally%n" +
@@ -639,7 +648,7 @@ private String expectedCompletionScriptForAutoCompleteApp() {
                 "  PREV_WORD=${COMP_WORDS[COMP_CWORD-1]}\n" +
                 "\n" +
                 "  COMMANDS=\"\"\n" +
-                "  FLAG_OPTS=\"-w --writeCommandScript -f --force -h --help\"\n" +
+                "  FLAG_OPTS=\"-w --writeCommandScript -f --force -h --help -V --version\"\n" +
                 "  ARG_OPTS=\"-c --factory -n --name -o --completionScript\"\n" +
                 "\n" +
                 "  compopt +o default\n" +