feat(module): improve error handling

lib/core/module.js

@@ -3,62 +3,69 @@ const fs = require('fs')
 const { uniq } = require('lodash')
 const hash = require('hash-sum')
 const { chainFn, sequence } = require('../common/utils')
-const Debug = require('debug')
-
-const debug = Debug('nuxt:module')
 
 module.exports = class ModuleContainer {
   constructor(nuxt) {
     this.nuxt = nuxt
     this.options = nuxt.options
-    this.requiredModules = []
+    this.requiredModules = {}
   }
 
   async ready() {
+    // Call before hook
     await this.nuxt.callHook('modules:before', this, this.options.modules)
+
     // Load every module in sequence
     await sequence(this.options.modules, this.addModule.bind(this))
+
     // Call done hook
     await this.nuxt.callHook('modules:done', this)
   }
 
   addVendor(vendor) {
     /* istanbul ignore if */
-    if (!vendor) {
+    if (!vendor || typeof vendor !== 'string') {
-      return
+      throw new Error('Invalid vendor:' + vendor)
     }
+
     this.options.build.vendor = uniq(this.options.build.vendor.concat(vendor))
   }
 
   addTemplate(template) {
     /* istanbul ignore if */
-    if (!template) {
+    if (!template || typeof template !== 'string') {
-      return
+      throw new Error('Invalid template:' + template)
     }
+
     // Validate & parse source
     const src = template.src || template
     const srcPath = path.parse(src)
     /* istanbul ignore if */
     if (!src || typeof src !== 'string' || !fs.existsSync(src)) {
-      /* istanbul ignore next */
+      throw new Error('Template not found:' + template)
-      debug('[nuxt] invalid template', template)
-      return
     }
+
     // Generate unique and human readable dst filename
-    const dst = template.fileName ||
+    const dst =
-      (path.basename(srcPath.dir) + '.' + srcPath.name + '.' + hash(src) + srcPath.ext)
+      template.fileName ||
+      `${path.basename(srcPath.dir)}.${srcPath.name}.${hash(src)}.${
+        srcPath.ext
+      }`
+
     // Add to templates list
     const templateObj = {
       src,
       dst,
       options: template.options
     }
+
     this.options.build.templates.push(templateObj)
     return templateObj
   }
 
   addPlugin(template) {
     const { dst } = this.addTemplate(template)
+
     // Add to nuxt plugins
     this.options.plugins.unshift({
       src: path.join(this.options.buildDir, dst),
@@ -75,72 +82,93 @@ module.exports = class ModuleContainer {
   }
 
   extendRoutes(fn) {
-    this.options.router.extendRoutes = chainFn(this.options.router.extendRoutes, fn)
+    this.options.router.extendRoutes = chainFn(
+      this.options.router.extendRoutes,
+      fn
+    )
   }
 
   requireModule(moduleOpts) {
-    // Require once
+    return this.addModule(moduleOpts, true /* require once */)
-    return this.addModule(moduleOpts, true)
   }
 
   async addModule(moduleOpts, requireOnce) {
-    /* istanbul ignore if */
+    let src
-    if (!moduleOpts) {
+    let options
-      return
+    let handler
+
+    // Type 1: String
+    if (typeof moduleOpts === 'string') {
+      src = moduleOpts
     }
 
-    // Allow using babel style array options
+    // Type 2: Babel style array
     if (Array.isArray(moduleOpts)) {
-      moduleOpts = {
+      src = moduleOpts[0]
-        src: moduleOpts[0],
+      options = moduleOpts[1]
-        options: moduleOpts[1]
+    }
+
+    // Type 3: Pure object
+    if (typeof moduleOpts === 'object') {
+      src = moduleOpts.src
+      options = moduleOpts.options
+      handler = moduleOpts.handler
+    }
+
+    // Resolve handler
+    if (!handler) {
+      try {
+        handler = require(this.nuxt.resolvePath(src))
+      } catch (e) {
+        console.error(e) // eslint-disable-line no-console
+        throw new Error('Error while resolving module: ' + src)
       }
     }
 
-    // Allows passing runtime options to each module
+    // Validate handler
-    const options = moduleOpts.options || (typeof moduleOpts === 'object' ? moduleOpts : {})
-    const src = moduleOpts.src || moduleOpts
-
-    // Resolve module
-    let module
-    if (typeof src === 'string') {
-      module = require(this.nuxt.resolvePath(src))
-    }
-
-    // Validate module
     /* istanbul ignore if */
-    if (typeof module !== 'function') {
+    if (typeof handler !== 'function') {
-      throw new Error(`[nuxt] Module ${JSON.stringify(src)} should export a function`)
+      throw new Error('Module should export a function: ' + src)
     }
 
-    // Module meta
+    // Resolve module meta
-    module.meta = module.meta || {}
+    const key = (handler.meta && handler.meta.name) || handler.name || src
-    let name = module.meta.name || module.name
 
-    // If requireOnce specified & module from NPM or with specified name
+    // Check requireOnce if possbile
-    if (requireOnce && name) {
+    if (requireOnce && typeof key === 'string') {
-      const alreadyRequired = this.requiredModules.indexOf(name) !== -1
+      const alreadyRequired = this.requiredModules[key]
       if (alreadyRequired) {
         return
       }
-      this.requiredModules.push(name)
+      this.requiredModules[key] = { src, options, handler }
     }
 
-    // Call module with `this` context and pass options
+    return new Promise((resolve, reject) => {
-    await new Promise((resolve, reject) => {
+      // Prepare callback
-      const result = module.call(this, options, (err) => {
+      const cb = err => {
+        // eslint-disable-next-line no-console
+        console.warn(
+          '[Depricated] Consider using async/await for module handlers.' +
+            'Supporting callbacks will be removed in next releases: ' +
+            src
+        )
         /* istanbul ignore if */
         if (err) {
           return reject(err)
         }
         resolve()
-      })
-      // If module send back a promise
-      if (result && result.then instanceof Function) {
-        return result.then(resolve)
       }
+
+      // Call module with `this` context and pass options
+      const result = handler.call(this, options, cb)
+
+      // If module send back a promise
+      if (result && result.then) {
+        return result
+      }
+
       // If not expecting a callback but returns no promise (=synchronous)
-      if (module.length < 2) {
+      if (handler.length < 2) {
         return resolve()
       }
     })

lib/core/nuxt.js

@@ -31,7 +31,9 @@ module.exports = class Nuxt {
     // Backward compatibility
     this.render = this.renderer.app
     this.renderRoute = this.renderer.renderRoute.bind(this.renderer)
-    this.renderAndGetWindow = this.renderer.renderAndGetWindow.bind(this.renderer)
+    this.renderAndGetWindow = this.renderer.renderAndGetWindow.bind(
+      this.renderer
+    )
 
     this._ready = this.ready().catch(this.errorHandler)
   }
@@ -51,11 +53,16 @@ module.exports = class Nuxt {
     } else if (typeof this.options.hooks === 'function') {
       this.options.hooks(this.hook)
     }
-    // Add nuxt modules
+
+    // Await for modules
     await this.moduleContainer.ready()
+
+    // Await for renderer to be ready
     await this.renderer.ready()
 
     this.initialized = true
+
+    // Call ready hook
     await this.callHook('ready', this)
 
     return this
@@ -63,14 +70,16 @@ module.exports = class Nuxt {
 
   plugin(name, fn) {
     // eslint-disable-next-line no-console
-    console.error(`[warn] nuxt.plugin('${name}',..) is deprecated. Please use new hooks system.`)
+    console.error(
+      `[Deprecated] nuxt.plugin('${name}',..) is deprecated. Please use new hooks system.`
+    )
 
     // A tiny backward compatibility util
     const hookMap = {
-      'ready': 'ready',
+      ready: 'ready',
-      'close': 'close',
+      close: 'close',
-      'listen': 'listen',
+      listen: 'listen',
-      'built': 'build:done'
+      built: 'build:done'
     }
 
     if (hookMap[name]) {
@@ -95,7 +104,7 @@ module.exports = class Nuxt {
     }
     debug(`Call ${name} hooks (${this._hooks[name].length})`)
     try {
-      await sequence(this._hooks[name], (fn) => fn(...args))
+      await sequence(this._hooks[name], fn => fn(...args))
     } catch (err) {
       console.error(`> Error on hook "${name}":`) // eslint-disable-line no-console
       console.error(err) // eslint-disable-line no-console
@@ -103,11 +112,11 @@ module.exports = class Nuxt {
   }
 
   addObjectHooks(hooksObj) {
-    Object.keys(hooksObj).forEach((name) => {
+    Object.keys(hooksObj).forEach(name => {
       let hooks = hooksObj[name]
-      hooks = (Array.isArray(hooks) ? hooks : [hooks])
+      hooks = Array.isArray(hooks) ? hooks : [hooks]
 
-      hooks.forEach((hook) => {
+      hooks.forEach(hook => {
         this.hook(name, hook)
       })
     })
@@ -115,7 +124,9 @@ module.exports = class Nuxt {
 
   listen(port = 3000, host = 'localhost') {
     return new Promise((resolve, reject) => {
-      const server = this.renderer.app.listen({ port, host, exclusive: false }, (err) => {
+      const server = this.renderer.app.listen(
+        { port, host, exclusive: false },
+        err => {
           /* istanbul ignore if */
           if (err) {
             return reject(err)
@@ -123,10 +134,17 @@ module.exports = class Nuxt {
 
           const _host = host === '0.0.0.0' ? 'localhost' : host
           // eslint-disable-next-line no-console
-        console.log('\n' + chalk.bgGreen.black(' OPEN ') + chalk.green(` http://${_host}:${port}\n`))
+          console.log(
+            '\n' +
+              chalk.bgGreen.black(' OPEN ') +
+              chalk.green(` http://${_host}:${port}\n`)
+          )
 
           // Close server on nuxt close
-        this.hook('close', () => new Promise((resolve, reject) => {
+          this.hook(
+            'close',
+            () =>
+              new Promise((resolve, reject) => {
                 // Destroy server by forcing every connection to be closed
                 server.destroy(err => {
                   debug('server closed')
@@ -136,17 +154,19 @@ module.exports = class Nuxt {
                   }
                   resolve()
                 })
-        }))
+              })
+          )
 
           this.callHook('listen', server, { port, host }).then(resolve)
-      })
+        }
+      )
 
       // Add server.destroy(cb) method
       enableDestroy(server)
     })
   }
 
-  errorHandler/* istanbul ignore next */() {
+  errorHandler() {
     // Apply plugins
     // eslint-disable-next-line no-console
     this.callHook('error', ...arguments).catch(console.error)
@@ -169,17 +189,21 @@ module.exports = class Nuxt {
   resolvePath(path) {
     // Try to resolve using NPM resolve path first
     try {
-      let resolvedPath = Module._resolveFilename(path, { paths: this.options.modulesDir })
+      let resolvedPath = Module._resolveFilename(path, {
+        paths: this.options.modulesDir
+      })
       return resolvedPath
     } catch (e) {
-      // Just continue
+      // Continue to try other methods
     }
+
     // Shorthand to resolve from project dirs
     if (path.indexOf('@@') === 0 || path.indexOf('~~') === 0) {
       return join(this.options.rootDir, path.substr(2))
     } else if (path.indexOf('@') === 0 || path.indexOf('~') === 0) {
       return join(this.options.srcDir, path.substr(1))
     }
+
     return resolve(this.options.srcDir, path)
   }