collect component identifier during render

Author: yyx990803

lib/component-normalizer.js

@@ -8,7 +8,7 @@ module.exports = function normalizeComponent (
   compiledTemplate,
   injectStyles,
   scopeId,
-  isServer
+  moduleIdentifier /* server only */
 ) {
   var esModule
   var scriptExports = rawScriptExports = rawScriptExports || {}
@@ -37,16 +37,20 @@ module.exports = function normalizeComponent (
   }
 
   var hook
-  if (isServer) {
+  if (moduleIdentifier) { // server build
     hook = function (context) {
       // context is injected if this is a cached call
       if (!context && typeof __VUE_SSR_CONTEXT__ !== 'undefined') {
         context = __VUE_SSR_CONTEXT__
       }
+      // inject component styles
       if (injectStyles) {
         injectStyles(this, context)
       }
-      // TODO: register module identifier for async chunk inferrence
+      // register component module identifier for async chunk inferrence
+      if (context && context._registeredComponents) {
+        context._registeredComponents.add(moduleIdentifier)
+      }
     }
     // used by ssr in case component is cached and beforeCreate
     // never gets called

lib/loader.js

@@ -1,4 +1,5 @@
 var path = require('path')
+var hash = require('hash-sum')
 var parse = require('./parser')
 var genId = require('./utils/gen-id')
 var normalize = require('./utils/normalize')
@@ -338,7 +339,7 @@ module.exports = function (content) {
   //   compiledTemplate,
   //   injectStyles,
   //   scopeId,
-  //   isServer
+  //   moduleIdentifier (server only)
   // )
   output += 'var Component = require(' +
     loaderUtils.stringifyRequest(loaderContext, '!' + componentNormalizerPath) +
@@ -380,9 +381,9 @@ module.exports = function (content) {
   output += '  /* scopeId */\n  '
   output += (hasScoped ? JSON.stringify(moduleId) : 'null') + ',\n'
 
-  // isServer
-  output += '  /* isServer */\n  '
-  output += (isServer ? 'true' : 'false') + '\n'
+  // moduleIdentifier (server only)
+  output += '  /* moduleIdentifier (server only) */\n  '
+  output += (isServer ? JSON.stringify(hash(this.request)) : 'null') + '\n'
 
   // close normalizeComponent call
   output += ')\n'

test/test.js

@@ -561,7 +561,7 @@ describe('vue-loader', function () {
     })
   })
 
-  it('SSR style extraction', done => {
+  it('SSR style and moduleId extraction', done => {
     bundle({
       target: 'node',
       entry: './test/fixtures/ssr-style.js',
@@ -578,7 +578,9 @@ describe('vue-loader', function () {
       const renderer = SSR.createBundleRenderer(code, {
         basedir: __dirname
       })
-      const context = {}
+      const context = {
+        _registeredComponents: new Set()
+      }
       renderer.renderToString(context, (err, res) => {
         if (err) return done(err)
         expect(res).to.contain('server-rendered')
@@ -590,6 +592,8 @@ describe('vue-loader', function () {
         expect(context.styles).to.contain('comp-a h2 {\n  color: #f00;')
         // from imported css file
         expect(context.styles).to.contain('h1 { color: red;')
+        // collect component identifiers during render
+        expect(Array.from(context._registeredComponents).length).to.equal(2)
         done()
       })
     })