fix(dev build): use portfinder (#30)

close #26

lib/dev.js

@@ -10,6 +10,7 @@ module.exports = async function dev (sourceDir, cliOptions = {}) {
   const serveStatic = require('koa-static')
   const HTMLPlugin = require('html-webpack-plugin')
   const history = require('connect-history-api-fallback')
+  const portfinder = require('portfinder')
 
   const prepare = require('./prepare')
   const HeadPlugin = require('./webpack/HeadPlugin')
@@ -71,7 +72,8 @@ module.exports = async function dev (sourceDir, cliOptions = {}) {
   }
 
   const compiler = webpack(config)
-  const port = cliOptions.port || options.siteConfig.port || 8080
+  portfinder.basePort = cliOptions.port || options.siteConfig.port || 8080
+  const port = await portfinder.getPortPromise()
 
   let isFirst = true
   compiler.hooks.done.tap('vuepress', () => {

package.json

@@ -70,6 +70,7 @@
     "nprogress": "^0.2.0",
     "object-assign": "^4.1.1",
     "optimize-css-assets-webpack-plugin": "^4.0.0",
+    "portfinder": "^1.0.13",
     "postcss-loader": "^2.1.3",
     "prismjs": "^1.13.0",
     "register-service-worker": "^1.2.0",

yarn.lock

@@ -298,6 +298,10 @@ async-limiter@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/async-limiter/-/async-limiter-1.0.0.tgz#78faed8c3d074ab81f22b4e985d79e8738f720f8"
 
+async@^1.5.2:
+  version "1.5.2"
+  resolved "https://registry.yarnpkg.com/async/-/async-1.5.2.tgz#ec6a61ae56480c0c3cb241c95618e20892f9672a"
+
 asynckit@^0.4.0:
   version "0.4.0"
   resolved "https://registry.yarnpkg.com/asynckit/-/asynckit-0.4.0.tgz#c79ed97f7f34cb8f2ba1bc9790bcc366474b4b79"
@@ -4229,6 +4233,14 @@ pn@^1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/pn/-/pn-1.1.0.tgz#e2f4cef0e219f463c179ab37463e4e1ecdccbafb"
 
+portfinder@^1.0.13:
+  version "1.0.13"
+  resolved "https://registry.yarnpkg.com/portfinder/-/portfinder-1.0.13.tgz#bb32ecd87c27104ae6ee44b5a3ccbf0ebb1aede9"
+  dependencies:
+    async "^1.5.2"
+    debug "^2.2.0"
+    mkdirp "0.5.x"
+
 posix-character-classes@^0.1.0:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/posix-character-classes/-/posix-character-classes-0.1.1.tgz#01eac0fe3b5af71a2a6c02feabb8c1fef7e00eab"