Rework docs to clarify action vs executable commands

CHANGELOG.md

@@ -15,6 +15,7 @@
     * can now define both `--foo` and `--no-foo`
     * custom event listeners: `--no-foo` on cli now emits `option:no-foo` (previously `option:foo`)
     * default value: defining `--no-foo` after defining `--foo` leaves the default value unchanged (previously set it to false)
+  * Change docs for `.command` to contrast action handler vs git-style executable. TypeScript now uses overloaded function. (#938)
 
 2.20.0 / 2019-04-02
 ==================

Readme.md

@@ -217,12 +217,12 @@ $ custom --list x,y,z
 The optional `version` method adds handling for displaying the command version. The default option flags are `-V` and `--version`, and when present the command prints the version number and exits.
 
 ```js
-    program.version('0.0.1');
+program.version('0.0.1');
 ```
 
 ```bash
-    $ ./examples/pizza -V
-    0.0.1
+$ ./examples/pizza -V
+0.0.1
 ```
 
 You may change the flags and description by passing additional parameters to the `version` method, using
@@ -232,39 +232,59 @@ the same syntax for flags as the `option` method. The version flags can be named
 program.version('0.0.1', '-v, --vers', 'output the current version');
 ```
 
-## Command-specific options
-
-You can attach options to a command.
+## Commands
 
-```js
-#!/usr/bin/env node
+You can specify (sub)commands for your top-level command using `.command`. There are two ways these can be implemented: using an action handler attached to the command, or as a separate executable file (described in more detail later). In the first parameter to `.command` you specify the command name and any command arguments. The arguments may be `<required>` or `[optional]`, and the last argument may also be `variadic...`.
 
-var program = require('commander');
+For example:
 
+```js
+// Command implemented using action handler (description is supplied separately to `.command`)
+// Returns new command for configuring.
 program
-  .command('rm <dir>')
-  .option('-r, --recursive', 'Remove recursively')
-  .action(function (dir, cmd) {
-    console.log('remove ' + dir + (cmd.recursive ? ' recursively' : ''))
-  })
+  .command('clone <source> [destination]')
+  .description('clone a repository into a newly created directory')
+  .action((source, destination) => {
+    console.log('clone command called');
+  });
 
-program.parse(process.argv)
+// Command implemented using separate executable file (description is second parameter to `.command`)
+// Returns top-level command for adding more commands.
+program
+  .command('start <service>', 'start named service')
+  .command('stop [service]', 'stop named service, or all if no name supplied');
 ```
 
-A command's options are validated when the command is used. Any unknown options will be reported as an error. However, if an action-based command does not define an action, then the options are not validated.
+### Specify the argument syntax
 
-## Variadic arguments
+You use `.arguments` to specify the arguments for the top-level command, and for subcommands they are included in the `.command` call. Angled brackets (e.g. `<required>`) indicate required input. Square brackets (e.g. `[optional]`) indicate optional input.
 
- The last argument of a command can be variadic, and only the last argument.  To make an argument variadic you have to
- append `...` to the argument name.  Here is an example:
 
 ```js
-#!/usr/bin/env node
+var program = require('commander');
 
-/**
- * Module dependencies.
- */
+program
+  .version('0.1.0')
+  .arguments('<cmd> [env]')
+  .action(function (cmd, env) {
+    cmdValue = cmd;
+    envValue = env;
+  });
+
+program.parse(process.argv);
+
+if (typeof cmdValue === 'undefined') {
+  console.error('no command given!');
+  process.exit(1);
+}
+console.log('command:', cmdValue);
+console.log('environment:', envValue || "no environment given");
+```
+
+ The last argument of a command can be variadic, and only the last argument.  To make an argument variadic you
+ append `...` to the argument name. For example:
 
+```js
 var program = require('commander');
 
 program
@@ -282,36 +302,37 @@ program
 program.parse(process.argv);
 ```
 
- An `Array` is used for the value of a variadic argument.  This applies to `program.args` as well as the argument passed
- to your action as demonstrated above.
+The variadic argument is passed to the action handler as an array. (And this also applies to `program.args`.)
 
-## Specify the argument syntax
+### Action handler (sub)commands
 
-```js
-#!/usr/bin/env node
+You can add options to a command that uses an action handler.
+The action handler gets passed a parameter for each argument you declared, and one additional argument which is the
+command object itself. This command argument has the values for the command-specific options added as properties.
 
+```js
 var program = require('commander');
 
 program
-  .version('0.1.0')
-  .arguments('<cmd> [env]')
-  .action(function (cmd, env) {
-     cmdValue = cmd;
-     envValue = env;
-  });
-
-program.parse(process.argv);
+  .command('rm <dir>')
+  .option('-r, --recursive', 'Remove recursively')
+  .action(function (dir, cmdObj) {
+    console.log('remove ' + dir + (cmdObj.recursive ? ' recursively' : ''))
+  })
 
-if (typeof cmdValue === 'undefined') {
-   console.error('no command given!');
-   process.exit(1);
-}
-console.log('command:', cmdValue);
-console.log('environment:', envValue || "no environment given");
+program.parse(process.argv)
 ```
-Angled brackets (e.g. `<cmd>`) indicate required input. Square brackets (e.g. `[env]`) indicate optional input.
 
-## Git-style sub-commands
+A command's options on the command line are validated when the command is used. Any unknown options will be reported as an error. However, if an action-based command does not define an action, then the options are not validated.
+
+Configuration options can be passed with the call to `.command()`. Specifying `true` for `opts.noHelp` will remove the command from the generated help output.
+
+### Git-style executable (sub)commands
+
+When `.command()` is invoked with a description argument, this tells commander that you're going to use separate executables for sub-commands, much like `git(1)` and other popular tools.
+Commander will search the executables in the directory of the entry script (like `./examples/pm`) with the name `program-subcommand`, like `pm-install`, `pm-search`.
+
+You handle the options for an executable (sub)command in the executable, and don't declare them at the top-level.
 
 ```js
 // file: ./examples/pm
@@ -325,19 +346,10 @@ program
   .parse(process.argv);
 ```
 
-When `.command()` is invoked with a description argument, no `.action(callback)` should be called to handle sub-commands, otherwise there will be an error. This tells commander that you're going to use separate executables for sub-commands, much like `git(1)` and other popular tools.  
-The commander will try to search the executables in the directory of the entry script (like `./examples/pm`) with the name `program-command`, like `pm-install`, `pm-search`.
-
-Options can be passed with the call to `.command()`. Specifying `true` for `opts.noHelp` will remove the subcommand from the generated help output. Specifying `true` for `opts.isDefault` will run the subcommand if no other subcommand is specified.
+Configuration options can be passed with the call to `.command()`. Specifying `true` for `opts.noHelp` will remove the command from the generated help output. Specifying `true` for `opts.isDefault` will run the subcommand if no other subcommand is specified.
 
 If the program is designed to be installed globally, make sure the executables have proper modes, like `755`.
 
-### `--harmony`
-
-You can enable `--harmony` option in two ways:
-* Use `#! /usr/bin/env node --harmony` in the sub-commands scripts. Note some os version don’t support this pattern.
-* Use the `--harmony` option when call the command, like `node --harmony examples/pm publish`. The `--harmony` option will be preserved when spawning sub-command process.
-
 ## Automated --help
 
  The help information is auto-generated based on the information commander already knows about your program, so the following `--help` info is for free:
@@ -486,6 +498,12 @@ If you use `ts-node` and  git-style sub-commands written as `.ts` files, you nee
 node -r ts-node/register pm.ts
 ```
 
+### Node options such as `--harmony`
+
+You can enable `--harmony` option in two ways:
+* Use `#! /usr/bin/env node --harmony` in the sub-commands scripts. (Note Windows does not support this pattern.)
+* Use the `--harmony` option when call the command, like `node --harmony examples/pm publish`. The `--harmony` option will be preserved when spawning sub-command process.
+
 ## Examples
 
 ```js

index.js

@@ -109,73 +109,41 @@ function Command(name) {
 }
 
 /**
- * Add command `name`.
+ * Define a command.
  *
- * The `.action()` callback is invoked when the
- * command `name` is specified via __ARGV__,
- * and the remaining arguments are applied to the
- * function for access.
- *
- * When the `name` is "*" an un-matched command
- * will be passed as the first arg, followed by
- * the rest of __ARGV__ remaining.
+ * There are two styles of command: pay attention to where to put the description.
  *
  * Examples:
  *
+ *      // Command implemented using action handler (description is supplied separately to `.command`)
  *      program
- *        .version('0.0.1')
- *        .option('-C, --chdir <path>', 'change the working directory')
- *        .option('-c, --config <path>', 'set config path. defaults to ./deploy.conf')
- *        .option('-T, --no-tests', 'ignore test hook')
- *
- *      program
- *        .command('setup')
- *        .description('run remote setup commands')
- *        .action(function() {
- *          console.log('setup');
- *        });
- *
- *      program
- *        .command('exec <cmd>')
- *        .description('run the given remote command')
- *        .action(function(cmd) {
- *          console.log('exec "%s"', cmd);
- *        });
- *
- *      program
- *        .command('teardown <dir> [otherDirs...]')
- *        .description('run teardown commands')
- *        .action(function(dir, otherDirs) {
- *          console.log('dir "%s"', dir);
- *          if (otherDirs) {
- *            otherDirs.forEach(function (oDir) {
- *              console.log('dir "%s"', oDir);
- *            });
- *          }
+ *        .command('clone <source> [destination]')
+ *        .description('clone a repository into a newly created directory')
+ *        .action((source, destination) => {
+ *          console.log('clone command called');
  *        });
  *
+ *      // Command implemented using separate executable file (description is second parameter to `.command`)
  *      program
- *        .command('*')
- *        .description('deploy the given env')
- *        .action(function(env) {
- *          console.log('deploying "%s"', env);
- *        });
+ *        .command('start <service>', 'start named service')
+ *        .command('stop [service]', 'stop named serice, or all if no name supplied');
  *
- *      program.parse(process.argv);
-  *
- * @param {String} name
- * @param {String} [desc] for git-style sub-commands
- * @return {Command} the new command
+ * @param {string} nameAndArgs - command name and arguments, args are `<required>` or `[optional]` and last may also be `variadic...`
+ * @param {Object|string} [actionOptsOrExecDesc] - configuration options (for action), or description (for executable)
+ * @param {Object} [execOpts] - configuration options (for executable)
+ * @return {Command} returns new command for action handler, or top-level command for executable command
  * @api public
  */
 
-Command.prototype.command = function(name, desc, opts) {
+Command.prototype.command = function(nameAndArgs, actionOptsOrExecDesc, execOpts) {
+  var desc = actionOptsOrExecDesc;
+  var opts = execOpts;
   if (typeof desc === 'object' && desc !== null) {
     opts = desc;
     desc = null;
   }
   opts = opts || {};
-  var args = name.split(/ +/);
+  var args = nameAndArgs.split(/ +/);
   var cmd = new Command(args.shift());
 
   if (desc) {

typings/commander-tests.ts

@@ -82,6 +82,7 @@ program.on('--help', () => {
 
 program
     .command('allow-unknown-option')
+    .description("description")
     .allowUnknownOption()
     .action(() => {
         console.log('unknown option is allowed');
@@ -94,6 +95,10 @@ program
         console.log(cmd, env);
     });
 
+program
+    .command("name1", "description")
+    .command("name2", "description", { isDefault:true })
+
 program.parse(process.argv);
 
-console.log('stuff');
+console.log('stuff');