Add support for groups of options and commands in the help

Readme.md

@@ -38,6 +38,7 @@ Read this in other languages: English | [简体中文](./Readme_zh-CN.md)
     - [.description and .summary](#description-and-summary)
     - [.helpOption(flags, description)](#helpoptionflags-description)
     - [.helpCommand()](#helpcommand)
+    - [Help Groups](#help-groups)
     - [More configuration](#more-configuration-2)
   - [Custom event listeners](#custom-event-listeners)
   - [Bits and pieces](#bits-and-pieces)
@@ -926,6 +927,14 @@ program.helpCommand('assist [command]', 'show assistance');
 
 (Or use `.addHelpCommand()` to add a command you construct yourself.)
 
+### Help Groups
+
+The help by default lists options under the the heading `Options:` and commands under `Commands:`. You can create your own groups
+with different headings. The high-level way is to set the desired group heading while adding the options and commands,
+using `.optionsGroup()` and `.commandsGroup()`. The low-level way is using `.helpGroup()` on an individual `Option` or `Command`
+
+Example file: [help-groups.js](./examples/help-groups.js)
+
 ### More configuration
 
 The built-in help is formatted using the Help class.

examples/help-groups.js

@@ -0,0 +1,75 @@
+const { Command, Option } = require('commander');
+
+// Show the two approaches for adding help groups, and how to customise the built-in help and version.
+
+const program = new Command();
+const devOptionsTitle = 'Development Options:';
+const managementCommandsTitle = 'Management Commands:';
+
+// The high-level approach is use .optionsGroup() and .commandsGroup() before adding the options/commands.
+const docker1 = program
+  .command('docker1')
+  .description('help groups created using .optionsGroup() and .commandsGroup()')
+  .addOption(new Option('-h, --hostname <name>', 'container host name'))
+  .addOption(new Option('-p, --port <number>', 'container port number'))
+  .optionsGroup(devOptionsTitle)
+  .option('-d, --debug', 'add extra trace information')
+  .option('-w, --watch', 'run and relaunch service on file changes');
+
+docker1
+  .command('run')
+  .description('create and run a new container from an image');
+docker1.command('exec').description('execute a command in a running container');
+
+docker1.commandsGroup(managementCommandsTitle);
+docker1.command('images').description('manage images');
+docker1.command('volumes').description('manage volumes');
+
+// The low-level approach is using .helpGroup() on the Option or Command.
+const docker2 = program
+  .command('docker2')
+  .description('help groups created using .helpGroup()')
+  .addOption(new Option('-h, --hostname <name>', 'container host name'))
+  .addOption(new Option('-p, --port <number>', 'container port number'))
+  .addOption(
+    new Option('-d, --debug', 'add extra trace information').helpGroup(
+      devOptionsTitle,
+    ),
+  )
+  .addOption(
+    new Option(
+      '-w, --watch',
+      'run and relaunch service on file changes',
+    ).helpGroup(devOptionsTitle),
+  );
+
+docker2
+  .command('run')
+  .description('create and run a new container from an image');
+docker2.command('exec').description('execute a command in a running container');
+
+docker2
+  .command('images')
+  .description('manage images')
+  .helpGroup(managementCommandsTitle);
+docker2
+  .command('volumes')
+  .description('manage volumes')
+  .helpGroup(managementCommandsTitle);
+
+// Customise group for built-ins by configuring them with default group set.
+program
+  .command('built-in')
+  .description('help groups for help and version')
+  .optionsGroup('Built-in Options:')
+  .version('v2.3.4')
+  .helpOption('-h, --help') // or .helpOption(true) to use default flags
+  .commandsGroup('Built-in Commands:')
+  .helpCommand('help [command]'); // or .helpCommand(true) to use default name
+
+program.parse();
+
+// Try the following:
+//    node help-groups.js help docker1
+//    node help-groups.js help docker2
+//    node help-groups.js help built-in

lib/command.js

@@ -80,6 +80,12 @@ class Command extends EventEmitter {
     /** @type {Command} */
     this._helpCommand = undefined; // lazy initialised, inherited
     this._helpConfiguration = {};
+    /** @type {string | undefined} */
+    this._helpGroupHeading = undefined; // soft initialised when added to parent
+    /** @type {string | undefined} */
+    this._defaultCommandGroup = undefined;
+    /** @type {string | undefined} */
+    this._defaultOptionGroup = undefined;
   }
 
   /**
@@ -400,11 +406,15 @@ class Command extends EventEmitter {
   helpCommand(enableOrNameAndArgs, description) {
     if (typeof enableOrNameAndArgs === 'boolean') {
       this._addImplicitHelpCommand = enableOrNameAndArgs;
+      if (enableOrNameAndArgs && this._defaultCommandGroup) {
+        // make the command to store the group
+        this._initCommandGroup(this._getHelpCommand());
+      }
       return this;
     }
 
-    enableOrNameAndArgs = enableOrNameAndArgs ?? 'help [command]';
-    const [, helpName, helpArgs] = enableOrNameAndArgs.match(/([^ ]+) *(.*)/);
+    const nameAndArgs = enableOrNameAndArgs ?? 'help [command]';
+    const [, helpName, helpArgs] = nameAndArgs.match(/([^ ]+) *(.*)/);
     const helpDescription = description ?? 'display help for command';
 
     const helpCommand = this.createCommand(helpName);
@@ -414,6 +424,8 @@ class Command extends EventEmitter {
 
     this._addImplicitHelpCommand = true;
     this._helpCommand = helpCommand;
+    // init group unless lazy create
+    if (enableOrNameAndArgs || description) this._initCommandGroup(helpCommand);
 
     return this;
   }
@@ -435,6 +447,7 @@ class Command extends EventEmitter {
 
     this._addImplicitHelpCommand = true;
     this._helpCommand = helpCommand;
+    this._initCommandGroup(helpCommand);
     return this;
   }
 
@@ -613,6 +626,7 @@ Expecting one of '${allowedValues.join("', '")}'`);
 -  already used by option '${matchingOption.flags}'`);
     }
 
+    this._initOptionGroup(option);
     this.options.push(option);
   }
 
@@ -640,6 +654,7 @@ Expecting one of '${allowedValues.join("', '")}'`);
       );
     }
 
+    this._initCommandGroup(command);
     this.commands.push(command);
   }
 
@@ -2294,6 +2309,75 @@ Expecting one of '${allowedValues.join("', '")}'`);
     return this;
   }
 
+  /**
+   * Set/get the help group heading for this subcommand in parent command's help.
+   *
+   * @param {string} [heading]
+   * @return {Command | string}
+   */
+
+  helpGroup(heading) {
+    if (heading === undefined) return this._helpGroupHeading ?? '';
+    this._helpGroupHeading = heading;
+    return this;
+  }
+
+  /**
+   * Set/get the default help group heading for subcommands added to this command.
+   * (This does not override a group set directly on the subcommand using .helpGroup().)
+   *
+   * @example
+   * program.commandsGroup('Development Commands:);
+   * program.command('watch')...
+   * program.command('lint')...
+   * ...
+   *
+   * @param {string} [heading]
+   * @returns {Command | string}
+   */
+  commandsGroup(heading) {
+    if (heading === undefined) return this._defaultCommandGroup ?? '';
+    this._defaultCommandGroup = heading;
+    return this;
+  }
+
+  /**
+   * Set/get the default help group heading for options added to this command.
+   * (This does not override a group set directly on the option using .helpGroup().)
+   *
+   * @example
+   * program
+   *   .optionsGroup('Development Options:')
+   *   .option('-d, --debug', 'output extra debugging')
+   *   .option('-p, --profile', 'output profiling information')
+   *
+   * @param {string} [heading]
+   * @returns {Command | string}
+   */
+  optionsGroup(heading) {
+    if (heading === undefined) return this._defaultOptionGroup ?? '';
+    this._defaultOptionGroup = heading;
+    return this;
+  }
+
+  /**
+   * @param {Option} option
+   * @private
+   */
+  _initOptionGroup(option) {
+    if (this._defaultOptionGroup && !option.helpGroupHeading)
+      option.helpGroup(this._defaultOptionGroup);
+  }
+
+  /**
+   * @param {Command} cmd
+   * @private
+   */
+  _initCommandGroup(cmd) {
+    if (this._defaultCommandGroup && !cmd.helpGroup())
+      cmd.helpGroup(this._defaultCommandGroup);
+  }
+
   /**
    * Set the name of the command from script filename, such as process.argv[1],
    * or require.main.filename, or __filename.
@@ -2448,22 +2532,27 @@ Expecting one of '${allowedValues.join("', '")}'`);
    */
 
   helpOption(flags, description) {
-    // Support disabling built-in help option.
+    // Support enabling/disabling built-in help option.
     if (typeof flags === 'boolean') {
-      // true is not an expected value. Do something sensible but no unit-test.
-      // istanbul ignore if
       if (flags) {
-        this._helpOption = this._helpOption ?? undefined; // preserve existing option
+        if (this._helpOption === null) this._helpOption = undefined; // reenable
+        if (this._defaultOptionGroup) {
+          // make the option to store the group
+          this._initOptionGroup(this._getHelpOption());
+        }
       } else {
         this._helpOption = null; // disable
       }
       return this;
     }
 
     // Customise flags and description.
-    flags = flags ?? '-h, --help';
-    description = description ?? 'display help for command';
-    this._helpOption = this.createOption(flags, description);
+    this._helpOption = this.createOption(
+      flags ?? '-h, --help',
+      description ?? 'display help for command',
+    );
+    // init group unless lazy create
+    if (flags || description) this._initOptionGroup(this._helpOption);
 
     return this;
   }
@@ -2492,6 +2581,7 @@ Expecting one of '${allowedValues.join("', '")}'`);
    */
   addHelpOption(option) {
     this._helpOption = option;
+    this._initOptionGroup(option);
     return this;
   }