fix: check the private field in package.json(#102) (#103)

It should not suggest `npm publish` if the package.json
has `private: true`.

index.js

@@ -148,16 +148,16 @@ function tag (newVersion, argv) {
   }
   checkpoint('tagging release %s', [newVersion])
   exec('git tag ' + tagOption + 'v' + newVersion + ' -m "' + formatCommitMessage(argv.message, newVersion) + '"', function (err, stdout, stderr) {
+    var message = 'git push --follow-tags origin master'
     var errMessage = null
     if (err) errMessage = err.message
     if (stderr) errMessage = stderr
+    if (pkg.private !== true) message += '; npm publish'
     if (errMessage) {
       console.log(chalk.red(errMessage))
       process.exit(1)
     } else {
-      checkpoint('Run `%s` to publish', [
-        'git push --follow-tags origin master; npm publish'
-      ], chalk.blue(figures.info))
+      checkpoint('Run `%s` to publish', [message], chalk.blue(figures.info))
     }
   })
 }

test.js

@@ -2,6 +2,7 @@
 
 'use strict'
 
+var extend = Object.assign || require('util')._extend
 var shell = require('shelljs')
 var fs = require('fs')
 var path = require('path')
@@ -18,10 +19,10 @@ function execCli (argString) {
   return shell.exec('node ' + cliPath + (argString != null ? ' ' + argString : ''))
 }
 
-function writePackageJson (version) {
-  fs.writeFileSync('package.json', JSON.stringify({
-    version: version
-  }), 'utf-8')
+function writePackageJson (version, option) {
+  option = option || {}
+  var pkg = extend(option, {version: version})
+  fs.writeFileSync('package.json', JSON.stringify(pkg), 'utf-8')
 }
 
 function writeGitPreCommitHook () {
@@ -197,4 +198,12 @@ describe('cli', function () {
     commit('feat: second commit')
     execCli('-n').code.should.equal(0)
   })
+
+  it('does not display `npm publish` if the package is private', function () {
+    writePackageJson('1.0.0', {private: true})
+
+    var result = execCli()
+    result.code.should.equal(0)
+    result.stdout.should.not.match(/npm publish/)
+  })
 })