feat: version data layer

Create a global variable "__VUEPRESS_VERSION__" to get current vuepress's version of the building documents

Author: ulivz

lib/app/clientEntry.js

@@ -1,10 +1,15 @@
-/* global BASE_URL, GA_ID, ga, SW_ENABLED */
+/* global BASE_URL, GA_ID, ga, SW_ENABLED, VUEPRESS_VERSION, LAST_COMMIT_HASH*/
 
 import { createApp } from './app'
 import { register } from 'register-service-worker'
 
 const { app, router } = createApp()
 
+window.__VUEPRESS_VERSION__ = {
+  version: VUEPRESS_VERSION,
+  hash: LAST_COMMIT_HASH
+}
+
 // Google analytics integration
 if (process.env.NODE_ENV === 'production' && GA_ID) {
   (function (i, s, o, g, r, a, m) {

lib/webpack/createBaseConfig.js

@@ -291,8 +291,19 @@ module.exports = function createBaseConfig ({
     .use(require('webpack/lib/DefinePlugin'), [{
       BASE_URL: JSON.stringify(siteConfig.base || '/'),
       GA_ID: siteConfig.ga ? JSON.stringify(siteConfig.ga) : false,
-      SW_ENABLED: !!siteConfig.serviceWorker
+      SW_ENABLED: !!siteConfig.serviceWorker,
+      VUEPRESS_VERSION: JSON.stringify(require('../../package.json').version),
+      LAST_COMMIT_HASH: JSON.stringify(getLastCommitHash())
     }])
 
   return config
 }
+
+function getLastCommitHash () {
+  const spawn = require('cross-spawn')
+  let hash
+  try {
+    hash = spawn.sync('git', ['log', '-1', '--format=%h']).stdout.toString('utf-8').trim()
+  } catch (error) {}
+  return hash
+}