feat: allow injecting Vue

lib/prepare.js

@@ -24,9 +24,11 @@ module.exports = async function prepare (sourceDir) {
   // 2. generate routes & user components registration code
   const routesCode = await genRoutesFile(options)
   const componentCode = await genComponentRegistrationFile(options)
+  const injectCode = await genInjectFile(options)
 
   await writeTemp('routes.js', [
     componentCode,
+    injectCode,
     routesCode
   ].join('\n\n'))
 
@@ -250,6 +252,17 @@ async function genRoutesFile ({ siteData: { pages }, sourceDir, pageFiles }) {
   )
 }
 
+async function genInjectFile ({ sourceDir }) {
+  const injectFile = path.resolve(sourceDir, '.vuepress/inject.js')
+  if (!fs.existsSync(injectFile)) {
+    return
+  }
+  return (
+    `import inject from ${JSON.stringify(injectFile)}\n` +
+    `inject(Vue)`
+  )
+}
+
 function sort (arr) {
   return arr.sort((a, b) => {
     if (a < b) return -1