useSubcommand draft

examples/use-subcommand.js

@@ -0,0 +1,58 @@
+#!/usr/bin/env node
+
+// This is an example of useSubcommand
+//
+// $ use-subcommand journal list myjounal
+// $ use-subcommand journal delete myjounal
+//
+// With options
+// $ use-subcommand journal -q delete -f myjounal
+
+// const { Command } = require('commander');
+const { Command } = require('..');
+
+function importSubCommand() {
+  const journalCmd = new Command()
+    .name('journal')
+    .description('Journal utils');
+
+  journalCmd
+    .command('list <path>')
+    .description('List journal')
+    .action((path, cmdInstance) => {
+      console.log('List journal');
+      console.log('Path is', path);
+      console.log('Quiet =', Boolean(cmdInstance.parent.quiet));
+    });
+
+  journalCmd
+    .command('delete <path>')
+    .description('Delete journal')
+    .option('-f, --force')
+    .action((path, cmdInstance) => {
+      console.log('List journal');
+      console.log('Path is', path);
+      console.log('Quiet =', Boolean(cmdInstance.parent.quiet));
+      console.log('Force =', Boolean(cmdInstance.force));
+    });
+
+  return journalCmd;
+}
+
+// this is supposedly a module, so in real case this would be `require`
+const journalSubCommand = importSubCommand();
+
+const program = new Command();
+program
+  .option('-q, --quiet')
+  .useSubcommand(journalSubCommand);
+
+program
+  .command('hello <name>')
+  .description('Greeting')
+  .action((name, cmdInstance) => {
+    console.log(`Hello ${name}!`);
+  });
+
+if (process.argv.length <= 2) program.help();
+program.parse(process.argv);

index.js

@@ -1210,6 +1210,46 @@ Command.prototype.help = function(cb) {
   process.exit();
 };
 
+/**
+ * Add action-like sub command
+ * command name is taken from name() property - must be defined
+ * 
+ * @returns {Command} `this` instance
+ */
+
+Command.prototype.useSubcommand = function(subCommand) {
+  if (this._args.length > 0) throw Error('useSubcommand cannot be applied to a command with explicit args');
+  if (!subCommand._name) throw Error('subCommand name is not specified');
+
+  var self     = subCommand;
+  var listener = function(args, unknown) {
+    // Parse any so-far unknown options
+    args    = args || [];
+    unknown = unknown || [];
+
+    var parsed = self.parseOptions(unknown);
+    if (parsed.args.length) args = parsed.args.concat(args);
+    unknown = parsed.unknown;
+
+    // Output help if necessary
+    const helpRequested    = unknown.includes('--help') || unknown.includes('-h');
+    const noFutherCommands = !args || !self.listeners('command:' + args[0]);
+    if (helpRequested && noFutherCommands) {
+      self.outputHelp();
+      process.exit(0);
+    }
+
+    self.parseArgs(args, unknown);
+  };
+
+  for (const label of [subCommand._name, subCommand._alias]) {
+    if (label) this.on('command:' + label, listener);
+  }
+  this.commands.push(subCommand);
+  subCommand.parent = this;
+  return this;
+};
+
 /**
  * Creates an instance of sub command
  *

typings/index.d.ts

@@ -204,6 +204,15 @@ declare namespace local {
 
     forwardSubcommands(): Command;
 
+    /**
+     * Add action-like sub command
+     * command name is taken from name() property - must be defined
+     * 
+     * @returns {Command} `this` instance
+     */
+
+    useSubcommand(subCommand : Command): Command;
+
     /**
      * Returns an object with all options values, including parent options values
      * This makes it especially useful with forwardSubcommands as it collects