feat: allow redirect to external url

lib/app/components/nuxt.js

@@ -7,6 +7,9 @@ export default {
   name: 'nuxt',
   props: ['nuxtChildKey'],
   render(h) {
+    if (this.nuxt._redirected) {
+      return h('div', [ 'redirecting.' ])
+    }
     // If there is some error
     if (this.nuxt.err) {
       return h('nuxt-error', {

lib/app/utils.js

@@ -132,11 +132,23 @@ export async function setContext(app, context) {
         path = status
         status = 302
       }
-      app.context.next({
-        path: path,
-        query: query,
-        status: status
-      })
+      if (path.charAt(0) === '/' && path.charAt(1) !== '/') {
+        app.context.next({
+          path: path,
+          query: query,
+          status: status
+        })
+      } else {
+        path = formatUrl(path, query)
+        if (process.server) {
+          app.context.res.setHeader('Location', path)
+          app.context.res.statusCode = status
+          app.nuxt._redirected = true
+        }
+        if (process.client) {
+          window.location = path
+        }
+      }
     }
     if (process.server) app.context.beforeNuxtRender = (fn) => context.beforeRenderFns.push(fn)
     if (process.client) app.context.nuxtState = window.__NUXT__
@@ -442,3 +454,60 @@ function escapeString(str) {
 function escapeGroup(group) {
   return group.replace(/([=!:$\/()])/g, '\\$1')
 }
+
+/**
+ * Format given url, append query to url query string
+ *
+ * @param  {string} url
+ * @param  {string} query
+ * @return {string}
+ */
+function formatUrl (url, query) {
+  let protocol
+  let index = url.indexOf('://')
+  if (index !== -1) {
+    protocol = url.substring(0, index)
+    url = url.substring(index + 3)
+  } else if (url.indexOf('//') === 0) {
+    url = url.substring(2)
+  }
+
+  let parts = url.split('/')
+  let result = (protocol ? protocol + '://' : '//') + parts.shift()
+
+  let path = parts.filter(Boolean).join('/')
+  let hash
+  parts = path.split('#')
+  if (parts.length === 2) {
+    path = parts[0]
+    hash = parts[1]
+  }
+
+  result += path ? '/' + path : ''
+
+  if (query && JSON.stringify(query) !== '{}') {
+    result += (url.split('?').length === 2 ? '&' : '?') + formatQuery(query)
+  }
+  result += hash ? '#' + hash : ''
+
+  return result
+}
+
+/**
+ * Transform data object to query string
+ *
+ * @param  {object} query
+ * @return {string}
+ */
+function formatQuery (query) {
+  return Object.keys(query).sort().map(key => {
+    var val = query[key]
+    if (val == null) {
+      return ''
+    }
+    if (Array.isArray(val)) {
+      return val.slice().map(val2 => [key, '=', val2].join('')).join('&')
+    }
+    return key + '=' + val
+  }).filter(Boolean).join('&')
+}