fix: allow to set program name

Author: egoist

README.md

@@ -30,6 +30,7 @@
 - [Projects Using CAC](#projects-using-cac)
 - [References](#references)
   - [CLI Instance](#cli-instance)
+    - [cac(name?)](#cacname)
     - [cli.command(name, description, config?)](#clicommandname-description-config)
     - [cli.option(name, description, config?)](#clioptionname-description-config)
     - [cli.parse(argv?)](#cliparseargv)
@@ -253,6 +254,10 @@ const cac = require('cac')
 const cli = cac()
 ```
 
+#### cac(name?)
+
+Create a CLI instance, optionally specify the program name which will be used to display in help and version message. When not set we use the basename of `argv[1]`.
+
 #### cli.command(name, description, config?)
 
 - Type: `(name: string, description: string) => Command`
@@ -370,7 +375,7 @@ Allow unknown options in this command, by default CAC will log an error when unk
 Add an example which will be displayed at the end of help message.
 
 ```ts
-type CommandExample = ((bin: string) => string) | string
+type CommandExample = ((name: string) => string) | string
 ```
 
 ### Events

examples/command-examples.js

@@ -4,8 +4,8 @@ const cli = require('../src/index')()
 cli
   .command('build', 'Build project')
   .example('cli build foo.js')
-  .example(bin => {
-    return `${bin} build foo.js`
+  .example(name => {
+    return `${name} build foo.js`
   })
   .option('--type [type]', 'Choose a project type')
 

src/CAC.ts

@@ -24,7 +24,8 @@ interface MriResult extends ParsedArgv {
 }
 
 class CAC extends EventEmitter {
-  bin: string
+  /** The program name to display in help and version message */
+  name: string
   commands: Command[]
   globalCommand: GlobalCommand
   matchedCommand: Command
@@ -45,8 +46,12 @@ class CAC extends EventEmitter {
    */
   rawOptions: MriResult['rawOptions']
 
-  constructor() {
+  /**
+   * @param name The program name to display in help and version message
+   */
+  constructor(name = '') {
     super()
+    this.name = name
     this.commands = []
     this.globalCommand = new GlobalCommand(this)
     this.globalCommand.usage('<command> [options]')
@@ -159,7 +164,9 @@ class CAC extends EventEmitter {
     } = {}
   ): ParsedArgv {
     this.rawArgs = argv
-    this.bin = argv[1] ? path.basename(argv[1]) : 'cli'
+    if (!this.name) {
+      this.name = argv[1] ? path.basename(argv[1]) : 'cli'
+    }
 
     let shouldParse = true
 

src/Command.ts

@@ -124,7 +124,7 @@ class Command {
   }
 
   outputHelp() {
-    const { bin, commands } = this.cli
+    const { name, commands } = this.cli
     const {
       versionNumber,
       options: globalOptions,
@@ -133,13 +133,13 @@ class Command {
 
     const sections: HelpSection[] = [
       {
-        body: `${bin}${versionNumber ? ` v${versionNumber}` : ''}`
+        body: `${name}${versionNumber ? ` v${versionNumber}` : ''}`
       }
     ]
 
     sections.push({
       title: 'Usage',
-      body: `  $ ${bin} ${this.usageText || this.rawName}`
+      body: `  $ ${name} ${this.usageText || this.rawName}`
     })
 
     const showCommands =
@@ -165,7 +165,7 @@ class Command {
         body: commands
           .map(
             command =>
-              `  $ ${bin}${
+              `  $ ${name}${
                 command.name === '' ? '' : ` ${command.name}`
               } --help`
           )
@@ -202,7 +202,7 @@ class Command {
         body: this.examples
           .map(example => {
             if (typeof example === 'function') {
-              return example(bin)
+              return example(name)
             }
             return example
           })
@@ -228,11 +228,11 @@ class Command {
   }
 
   outputVersion() {
-    const { bin } = this.cli
+    const { name } = this.cli
     const { versionNumber } = this.cli.globalCommand
     if (versionNumber) {
       console.log(
-        `${bin}/${versionNumber} ${process.platform}-${process.arch} node-${
+        `${name}/${versionNumber} ${process.platform}-${process.arch} node-${
           process.version
         }`
       )