added addArguments method

examples/advanced-argument.js

@@ -0,0 +1,24 @@
+#!/usr/bin/env node
+
+// This example shows specifying the arguments using addArgument() function.
+
+// const { Command } = require('commander'); // (normal include)
+const { Command, Argument } = require('../'); // include commander in git clone of commander repo
+const program = new Command();
+
+program
+  .version('0.1.0')
+  .addArgument(new Argument('<username>', 'user to login'))
+  .addArgument(new Argument('[password]', 'password'))
+  .description('test command')
+  .action((username, password) => {
+    console.log('username:', username);
+    console.log('environment:', password || 'no password given');
+  });
+
+program.parse();
+
+// Try the following:
+//    node arguments.js --help
+//    node arguments.js user
+//    node arguments.js user secret

index.js

@@ -344,6 +344,20 @@ class Help {
   }
 }
 
+class Argument {
+  /**
+   * Initialize a new argument with description.
+   *
+   * @param {string} arg
+   * @param {object} [description]
+   */
+
+  constructor(arg, description) {
+    this.argDetails = parseArg(arg);
+    this.description = description || '';
+  }
+}
+
 class Option {
   /**
    * Initialize a new `Option` with the given `flags` and `description`.
@@ -755,6 +769,20 @@ class Command extends EventEmitter {
     return this._parseExpectedArgs(desc.split(/ +/));
   };
 
+  /**
+   * Define argument syntax for the command.
+   * @param {Argument} argument
+   */
+  addArgument(argument) {
+    this._args.push(argument.argDetails);
+    if (!this._argsDescription) {
+      this._argsDescription = {};
+    }
+    this._argsDescription[argument.argDetails.name] = argument.description;
+    this._validateArgs();
+    return this;
+  }
+
   /**
    * Override default decision whether to add implicit help command.
    *
@@ -804,37 +832,20 @@ class Command extends EventEmitter {
   _parseExpectedArgs(args) {
     if (!args.length) return;
     args.forEach((arg) => {
-      const argDetails = {
-        required: false,
-        name: '',
-        variadic: false
-      };
-
-      switch (arg[0]) {
-        case '<':
-          argDetails.required = true;
-          argDetails.name = arg.slice(1, -1);
-          break;
-        case '[':
-          argDetails.name = arg.slice(1, -1);
-          break;
-      }
-
-      if (argDetails.name.length > 3 && argDetails.name.slice(-3) === '...') {
-        argDetails.variadic = true;
-        argDetails.name = argDetails.name.slice(0, -3);
-      }
-      if (argDetails.name) {
-        this._args.push(argDetails);
-      }
+      const argDetails = parseArg(arg);
+      argDetails && this._args.push(argDetails);
     });
+    this._validateArgs();
+    return this;
+  };
+
+  _validateArgs() {
     this._args.forEach((arg, i) => {
       if (arg.variadic && i < this._args.length - 1) {
         throw new Error(`only the last argument can be variadic '${arg.name}'`);
       }
     });
-    return this;
-  };
+  }
 
   /**
    * Register callback to use as replacement for calling process.exit.
@@ -1834,7 +1845,9 @@ class Command extends EventEmitter {
   description(str, argsDescription) {
     if (str === undefined && argsDescription === undefined) return this._description;
     this._description = str;
-    this._argsDescription = argsDescription;
+    if (argsDescription) {
+      this._argsDescription = argsDescription;
+    }
     return this;
   };
 
@@ -2079,6 +2092,7 @@ exports.program = exports; // More explicit access to global command.
 
 exports.Command = Command;
 exports.Option = Option;
+exports.Argument = Argument;
 exports.CommanderError = CommanderError;
 exports.InvalidOptionArgumentError = InvalidOptionArgumentError;
 exports.Help = Help;
@@ -2198,3 +2212,29 @@ function incrementNodeInspectorPort(args) {
     return arg;
   });
 }
+
+function parseArg(arg) {
+  const argDetails = {
+    required: false,
+    name: '',
+    variadic: false
+  };
+
+  switch (arg[0]) {
+    case '<':
+      argDetails.required = true;
+      argDetails.name = arg.slice(1, -1);
+      break;
+    case '[':
+      argDetails.name = arg.slice(1, -1);
+      break;
+  }
+
+  if (argDetails.name.length > 3 && argDetails.name.slice(-3) === '...') {
+    argDetails.variadic = true;
+    argDetails.name = argDetails.name.slice(0, -3);
+  }
+  if (argDetails.name) {
+    return argDetails;
+  }
+}