feat(help): Showing help message on -h or --help

closes #1

README.md

@@ -38,7 +38,7 @@ var options = {
   noExit: true | false, // simple-bin-help by default calls process.exit
   help: 'help string',  // to display if invalid arguments
   minArguments: n,      // min number of arguments to check
-  pkg: packageObject,   // package object or path for better message
+  pkg: packageObject,   // package (or pkg) object or path for better message
   packagePath: 'path/to/package.json',
   onFail: fn            // user-supplied function to be called after help has been shown
 };
@@ -48,9 +48,13 @@ require('simple-bin-help')(options);
 If `noExit` is true, the call simply shows the error message if number of arguments is
 invalid and returns a boolean result.
 
+For more examples, see [examples/basic.js](examples/basic.js) file that calls the method
+with several permutations.
+
 ## Bonus features
 
-Includes and calls the [update-notifier]() module by default.
+* Includes and calls the [update-notifier]() module by default.
+* If passed `-h` or `--help` option, shows the help message.
 
 ### Small print
 

examples/basic.js

@@ -0,0 +1,34 @@
+const simpleBinHelp = require('..')
+
+var options = {
+  noExit: true,
+  help: 'basic example help',
+  minArguments: 3,
+  pkg: {}
+}
+console.log('min arguments 3, calling with empty package')
+simpleBinHelp(options)
+
+options = {
+  noExit: true,
+  help: 'has package object',
+  minArguments: 3,
+  pkg: {
+    name: 'basic-example',
+    version: '1.0.0-dev'
+  }
+}
+console.log('min arguments 3, calling with package')
+simpleBinHelp(options)
+
+options = {
+  noExit: true,
+  help: 'basic example, path to real package.json',
+  minArguments: 3,
+  packagePath: __dirname + '/../package.json',
+  onFail: function () {
+    console.log('fail callback, show extra info')
+  }
+}
+console.log('real package.json path')
+simpleBinHelp(options)

index.js

@@ -2,17 +2,24 @@
 
 const updateNotifier = require('update-notifier')
 
+function isHelp (arg) {
+  return arg === '-h' ||
+    arg === '--help'
+}
+
+function hasHelpArgument (args) {
+  return args.some(isHelp)
+}
+
 function noArguments (minLength, args) {
   console.assert(Array.isArray(args), 'missing arguments')
   return args.length < minLength
 }
 
 function getPackage (options) {
-  var pkg
+  var pkg = options.pkg || options.package
 
-  if (options.package) {
-    pkg = options.package
-  } else if (options.packagePath) {
+  if (!pkg && options.packagePath) {
     pkg = require(options.packagePath)
   }
 
@@ -26,7 +33,13 @@ function showHelp (options) {
 
   var pkgInfo
   if (pkg) {
-    pkgInfo = pkg.name + '@' + pkg.version + '\n - ' + pkg.description
+    pkgInfo = pkg.name ? pkg.name : ''
+    if (pkg.version) {
+      pkgInfo += '@' + pkg.version
+    }
+    if (pkg.description) {
+      pkgInfo += '\n - ' + pkg.description
+    }
   }
 
   if (pkgInfo) {
@@ -43,32 +56,43 @@ function showHelp (options) {
   }
 }
 
+function finish (options) {
+  if (options.noExit) {
+    return false
+  }
+  process.exit(0)
+}
+
 function simpleBinHelp (options, cliArguments) {
   console.assert(options, 'missing options')
 
   if (!cliArguments) {
     cliArguments = process.argv
   }
 
+  if (hasHelpArgument(cliArguments)) {
+    showHelp(options)
+    finish(options)
+    return true
+  }
+
   var pkg = getPackage(options)
-  if (pkg) {
+  if (pkg && pkg.name && pkg.version) {
     updateNotifier({ pkg: pkg }).notify()
   }
 
   var minArguments = options.minArguments ||
     options.min ||
     options.n
+
   if (noArguments(minArguments, cliArguments)) {
     showHelp(options)
 
     if (typeof options.onFail === 'function') {
       options.onFail()
     }
 
-    if (options.noExit) {
-      return false
-    }
-    process.exit(0)
+    return finish(options)
   }
 
   return true

package.json

@@ -9,7 +9,8 @@
     "commit": "git-issues && commit-wizard",
     "issues": "git-issues",
     "size": "t=\"$(npm pack .)\"; wc -c \"${t}\"; tar tvf \"${t}\"; rm \"${t}\";",
-    "lint": "standard *.js spec/*.js"
+    "lint": "standard *.js spec/*.js examples/*.js",
+    "basic": "node examples/basic.js"
   },
   "files": [
     "index.js"
@@ -48,7 +49,8 @@
       "commit-msg": "validate-commit-msg",
       "pre-commit": [
         "npm run lint",
-        "npm test"
+        "npm test",
+        "npm run basic"
       ],
       "pre-push": [
         "npm run size"

spec/spec.js

@@ -39,4 +39,20 @@ describe('simple bin help', function () {
     la(!simpleHelp(options, cliArguments), 'not enough arguments')
     la(called, 'onFail called')
   })
+
+  it('can show help with -h', function () {
+    var options = {
+      noExit: true
+    }
+    var cliArguments = ['-h']
+    la(simpleHelp(options, cliArguments))
+  })
+
+  it('can show help with --help', function () {
+    var options = {
+      noExit: true
+    }
+    var cliArguments = ['--help']
+    la(simpleHelp(options, cliArguments))
+  })
 })