diff --git a/package.json b/package.json
index 3a72cbfdc..e1b9ff890 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,8 @@
   "workspaces": [
     "packages/@vue/*"
   ],
-	"devDependencies": {
-		"lerna": "^2.5.1"
-	}
+  "devDependencies": {
+    "debug": "^3.1.0",
+    "lerna": "^2.5.1"
+  }
 }
diff --git a/packages/@vue/cli/lib/Creator.js b/packages/@vue/cli/lib/Creator.js
index 0bff6be25..d3fee8894 100644
--- a/packages/@vue/cli/lib/Creator.js
+++ b/packages/@vue/cli/lib/Creator.js
@@ -7,6 +7,7 @@ const { execSync } = require('child_process')
 const GeneratorAPI = require('./GeneratorAPI')
 const writeFileTree = require('./util/writeFileTree')
 
+const debug = require('debug')
 const rcPath = path.join(os.homedir(), '.vuerc')
 const isMode = _mode => ({ mode }) => _mode === mode
 
@@ -19,21 +20,27 @@ const defaultOptions = {
 
 module.exports = class Creator {
   constructor (name, generators) {
-    this.name = name
     const { modePrompt, featurePrompt } = this.resolveIntroPrompts()
     this.modePrompt = modePrompt
     this.featurePrompt = featurePrompt
     this.outroPrompts = this.resolveOutroPrompts()
     this.injectedPrompts = []
-    this.deps = {}
-    this.devDeps = {}
-    this.scripts = {}
-    this.packageFields = {}
-    this.files = {}
-    this.postCreateMessages = []
     this.promptCompleteCbs = []
     this.fileMiddlewares = []
 
+    this.pkg = {
+      name,
+      version: '0.1.0',
+      private: true,
+      scripts: {},
+      dependencies: {},
+      devDependencies: {}
+    }
+    // for conflict resolution
+    this.depSources = {}
+    // virtual file tree
+    this.files = {}
+
     generators.forEach(generator => {
       generator.module(new GeneratorAPI(this, generator))
     })
@@ -42,29 +49,28 @@ module.exports = class Creator {
   async create (path) {
     // prompt
     let options = await inquirer.prompt(this.resolveFinalPrompts())
-    let needSave = false
+    debug('rawOptions')(options)
+
     if (options.mode === 'saved') {
       options = this.loadSavedOptions()
     } else if (options.mode === 'default') {
       options = defaultOptions
-    } else if (options.save) {
-      needSave = true
     }
     options.features = options.features || []
 
-    // run cbs (register generators)
+    // run cb registered by generators
     this.promptCompleteCbs.forEach(cb => cb(options))
-
-    // save after prompt complete cbs are run, since generators may modify
-    // options in the callback
-    if (needSave) {
+    debug('options')(options)
+    // save options
+    if (options.mode === 'manual' && options.save) {
       this.saveOptions(options)
     }
 
-    // resolve deps, scripts and generate final package.json
-    this.resolvePackage()
     // wait for file resolve
     await this.resolveFiles()
+    // set package.json
+    this.resolvePkg()
+    this.files['package.json'] = JSON.stringify(this.pkg, null ,2)
     // write file tree to disk
     await writeFileTree(path, this.files)
   }
@@ -156,14 +162,14 @@ module.exports = class Creator {
         return options.mode === 'manual' && originalWhen(options)
       }
     })
-    const ret = [].concat(
+    const prompts = [].concat(
       this.modePrompt,
       this.featurePrompt,
       this.injectedPrompts,
       this.outroPrompts
     )
-    console.log(ret)
-    return ret
+    debug('prompts')(prompts)
+    return prompts
   }
 
   loadSavedOptions () {
@@ -191,45 +197,21 @@ module.exports = class Creator {
     }
   }
 
-  resolvePackage () {
-    const { dependencies, devDependencies } = this.resolveDeps()
-    const scripts = this.resolveScripts()
-    const additionalFields = this.resolvePackageFields()
-    const pkg = Object.assign({}, additionalFields, {
-      name: this.name,
-      version: '0.1.0',
-      private: true,
-      scripts,
-      dependencies,
-      devDependencies
-    })
-    this.files['package.json'] = JSON.stringify(pkg, null, 2)
-  }
-
-  // TODO
-  resolveDeps () {
-    const dependencies = this.deps
-    const devDependencies = this.devDeps
-    return {
-      dependencies,
-      devDependencies
-    }
-  }
-
-  // TODO
-  resolveScripts () {
-    return this.scripts
-  }
-
-  // TODO
-  resolvePackageFields () {
-    return this.packageFields
+  resolvePkg () {
+    const sortDeps = deps => Object.keys(deps).sort().reduce((res, name) => {
+      res[name] = deps[name]
+      return res
+    }, {})
+    this.pkg.dependencies = sortDeps(this.pkg.dependencies)
+    this.pkg.devDependencies = sortDeps(this.pkg.devDependencies)
+    debug('pkg')(this.pkg)
   }
 
   async resolveFiles () {
     for (const middleware of this.fileMiddlewares) {
       await middleware(this.files)
     }
+    debug('files')(this.files)
   }
 }
 
diff --git a/packages/@vue/cli/lib/GeneratorAPI.js b/packages/@vue/cli/lib/GeneratorAPI.js
index 52af53a1c..9290c703a 100644
--- a/packages/@vue/cli/lib/GeneratorAPI.js
+++ b/packages/@vue/cli/lib/GeneratorAPI.js
@@ -1,4 +1,7 @@
 const { error } = require('./util/log')
+const mergeDeps = require('./util/mergeDeps')
+const isObject = val => val && typeof val === 'object'
+const isFunction = val => typeof val === 'function'
 
 module.exports = class GeneratorAPI {
   constructor (creator, generator) {
@@ -32,31 +35,47 @@ module.exports = class GeneratorAPI {
     this.creator.promptCompleteCbs.push(cb)
   }
 
-  injectDeps (deps) {
-    Object.assign(this.creator.deps, deps)
-  }
-
-  injectDevDeps(deps) {
-    Object.assign(this.creator.devDeps, deps)
-  }
-
-  injectScripts (scripts) {
-    Object.assign(this.creator.scripts, scripts)
-  }
-
-  injectPackageFields (fields) {
-    Object.assign(this.creator.packageFields, fields)
+  onCreateComplete (msg) {
+    this.creator.onCreateCompleteCbs.push(cb)
   }
 
   injectFileMiddleware (middleware) {
     this.creator.fileMiddlewares.push(middleware)
   }
 
-  renderFile (file) {
-    return file
+  extendPackage (fields, options = { merge: true }) {
+    const pkg = this.creator.pkg
+    const toMerge = isFunction(fields) ? fields(pkg) : fields
+    for (const key in toMerge) {
+      if (!options.merge || !(key in pkg)) {
+        pkg[key] = toMerge[key]
+      } else {
+        const value = toMerge[key]
+        const existing = pkg[key]
+        if (Array.isArray(value) && Array.isArray(existing)) {
+          pkg[key] = existing.concat(value)
+        } else if (isObject(value) && isObject(existing)) {
+          if (key === 'dependencies' || key === 'devDependencies') {
+            // use special version resolution merge
+            pkg[key] = mergeDeps(
+              this.generator.id,
+              existing,
+              value,
+              this.creator.depSources
+            )
+          } else {
+            pkg[key] = Object.assign({}, existing, value)
+          }
+        } else {
+          pkg[key] = value
+        }
+      }
+    }
   }
 
-  onCreateComplete (msg) {
-    this.creator.onCreateCompleteCbs.push(cb)
+  renderFile (file, additionalData, ejsOptions) {
+    // TODO render file based on generator path
+    // render with ejs & options
+    return file
   }
 }
diff --git a/packages/@vue/cli/lib/create.js b/packages/@vue/cli/lib/create.js
index 51ac83aa8..6ea65599b 100644
--- a/packages/@vue/cli/lib/create.js
+++ b/packages/@vue/cli/lib/create.js
@@ -2,6 +2,7 @@ const fs = require('fs')
 const path = require('path')
 const program = require('commander')
 const Creator = require('./Creator')
+const debug = require('debug')('create')
 const Generator = require('./Generator')
 const { warn, error } = require('./util/log')
 const resolveInstalledGenerators = require('./util/resolveInstalledGenerators')
@@ -21,6 +22,8 @@ const builtInGenerators = fs
   .readdirSync(path.resolve(__dirname, './generators'))
   .map(id => new Generator(id, `./generators/${id}`))
 
+debug(builtInGenerators)
+
 const installedGenerators = resolveInstalledGenerators().map(id => {
   return new Generator(id)
 })
diff --git a/packages/@vue/cli/lib/generators/babel/index.js b/packages/@vue/cli/lib/generators/babel/index.js
index 36e6e5c16..ba9f7a255 100644
--- a/packages/@vue/cli/lib/generators/babel/index.js
+++ b/packages/@vue/cli/lib/generators/babel/index.js
@@ -1,9 +1,11 @@
 module.exports = api => {
   api.onPromptComplete(options => {
     if (!options.features.includes('ts')) {
-      api.injectDevDeps({
-        '@vue/cli-plugin-babel': '^1.0.0',
-        'babel-preset-vue-app': '^2.0.0'
+      api.extendPackage({
+        devDependencies: {
+          '@vue/cli-plugin-babel': '^1.0.0',
+          'babel-preset-vue-app': '^2.0.0'
+        }
       })
       api.injectFileMiddleware(files => {
         files['.babelrc'] = api.renderFile('.babelrc')
diff --git a/packages/@vue/cli/lib/generators/unit/files/Hello.spec.js b/packages/@vue/cli/lib/generators/unit/files/Hello.spec.js
index 06df0b74f..f804b5098 100644
--- a/packages/@vue/cli/lib/generators/unit/files/Hello.spec.js
+++ b/packages/@vue/cli/lib/generators/unit/files/Hello.spec.js
@@ -1,11 +1,11 @@
 import { shallow } from 'vue-test-utils'
-import Hello from '@/components/Hello.vue'
-<% if (assertionLibrary === 'expect') { %>
+<%_ if (assertionLibrary === 'expect') { _%>
 import { expect } from 'expect'
-<% } %>
-<% if (assertionLibrary === 'chai') { %>
+<%_ } _%>
+<%_ if (assertionLibrary === 'chai') { _%>
 import { expect } from 'chai'
-<% } %>
+<%_ } _%>
+import Hello from '@/components/Hello.vue'
 
 describe('Hello.vue', () => {
   it('renders props.msg when passed', () => {
@@ -13,14 +13,14 @@ describe('Hello.vue', () => {
     const wrapper = shallow(Hello, {
       context: { props: { msg } }
     })
-    <% if (assertionLibrary === 'expect' || unit === 'jest') { %>
+    <%_ if (assertionLibrary === 'expect' || unit === 'jest') { _%>
     expect(wrapper.text()).toBe(msg)
-    <% } %>
-    <% if (assertionLibrary === 'chai') { %>
+    <%_ } _%>
+    <%_ if (assertionLibrary === 'chai') { _%>
     expect(wrapper.text()).to.equal(msg)
-    <% } %>
-    <% if (assertionLibrary === 'custom') { %>
+    <%_ } _%>
+    <%_ if (assertionLibrary === 'custom') { _%>
     // assert wrapper.text() equals msg
-    <% } %>
+    <%_ } _%>
   })
 })
diff --git a/packages/@vue/cli/lib/generators/unit/jest.js b/packages/@vue/cli/lib/generators/unit/jest.js
index 930c08ec9..0167907a2 100644
--- a/packages/@vue/cli/lib/generators/unit/jest.js
+++ b/packages/@vue/cli/lib/generators/unit/jest.js
@@ -1,15 +1,13 @@
 module.exports = (api, options) => {
-  api.injectDevDeps({
-    '@vue/cli-plugin-unit-jest': '^1.0.0',
-    "jest": "^22.0.4",
-    'vue-test-utils': '^1.0.0'
-  })
-
-  api.injectScripts({
-    test: 'jest'
-  })
-
-  api.injectPackageFields({
+  api.extendPackage({
+    scripts: {
+      test: 'jest'
+    },
+    devDependencies: {
+      '@vue/cli-plugin-unit-jest': '^1.0.0',
+      "jest": "^22.0.4",
+      'vue-test-utils': '^1.0.0'
+    },
     "jest": {
       "moduleFileExtensions": [
         "js",
diff --git a/packages/@vue/cli/lib/generators/unit/mocha-webpack.js b/packages/@vue/cli/lib/generators/unit/mocha-webpack.js
index 82328f67e..a754951fb 100644
--- a/packages/@vue/cli/lib/generators/unit/mocha-webpack.js
+++ b/packages/@vue/cli/lib/generators/unit/mocha-webpack.js
@@ -1,17 +1,19 @@
 module.exports = (api, options) => {
-  const dependencies = {
+  const devDependencies = {
     '@vue/cli-plugin-unit-mocha-webpack': '^1.0.0',
     'vue-test-utils': '^1.0.0'
   }
   if (options.assertionLibrary === 'chai') {
-    dependencies.chai = '^4.1.2'
+    devDependencies.chai = '^4.1.2'
   } else if (options.assertionLibrary === 'expect') {
-    dependencies.expect = '^22.0.3'
+    devDependencies.expect = '^22.0.3'
   }
-  api.injectDevDeps(dependencies)
 
-  api.injectScripts({
-    test: 'vue-cli-service test'
+  api.extendPackage({
+    devDependencies,
+    scripts: {
+      test: 'vue-cli-service test'
+    }
   })
 
   api.injectFileMiddleware(files => {
diff --git a/packages/@vue/cli/lib/util/log.js b/packages/@vue/cli/lib/util/log.js
index 8d9448792..05634501e 100644
--- a/packages/@vue/cli/lib/util/log.js
+++ b/packages/@vue/cli/lib/util/log.js
@@ -1,21 +1,25 @@
 const chalk = require('chalk')
 
-exports.info = msg => {
-  console.log(chalk.gray(`\n  ${msg}\n`))
+const format = (label, msg) => {
+  return msg.split('\n').map((line, i) => {
+    return i === 0
+      ? `\n  ${label} ${line}`
+      : `  ${line}`
+  }).join('\n') + '\n'
 }
 
 exports.success = msg => {
-  console.log(chalk.green(`\n  ${msg}\n`))
+  console.log(format(chalk.bgGreen(' OK '), chalk.green(msg)))
 }
 
 exports.warn = msg => {
-  console.warn(chalk.yellow(`\n  ${msg}\n`))
+  console.warn(format(chalk.bgYellow(chalk.black(' WARN ')), chalk.yellow(msg)))
 }
 
 exports.error = msg => {
-  console.error(`\n  ${chalk.bgRed(' ERROR ')} ${chalk.red(msg)}\n`)
+  console.error(format(chalk.bgRed(' ERROR '), chalk.red(msg)))
   if (msg instanceof Error) {
-    console.log(msg.stack)
+    console.error(msg.stack)
   }
   process.exit(1)
 }
diff --git a/packages/@vue/cli/lib/util/mergeDeps.js b/packages/@vue/cli/lib/util/mergeDeps.js
new file mode 100644
index 000000000..0ddb3b38d
--- /dev/null
+++ b/packages/@vue/cli/lib/util/mergeDeps.js
@@ -0,0 +1,54 @@
+const semver = require('semver')
+const { warn } = require('./log')
+
+module.exports = function resolveDeps (generatorId, to, from, sources) {
+  const res = Object.assign({}, to)
+  for (const name in from) {
+    const r1 = to[name]
+    const r2 = from[name]
+    const sourceGeneratorId = sources[name]
+
+    if (!semver.validRange(r2)) {
+      warn(
+        `invalid version range for dependency "${name}":\n\n` +
+        `- ${r2} injected by generator "${generatorId}"`
+      )
+      continue
+    }
+
+    if (!r1) {
+      res[name] = r2
+    } else {
+      const r = tryGetNewerRange(r1, r2)
+      const didGetNewer = !!r
+      // if failed to infer newer version, use existing one because it's likely
+      // built-in
+      res[name] = didGetNewer ? r : r1
+      // if changed, update source
+      if (res[name] === r2) {
+        sources[name] = generatorId
+      }
+      // warn incompatible version requirements
+      if (!semver.intersects(r1, r2)) {
+        warn(
+          `conflicting versions for project dependency "${name}":\n\n` +
+          `- ${r1} injected by generator "${sourceGeneratorId}"\n` +
+          `- ${r2} injected by generator "${generatorId}"\n\n` +
+          `Using ${didGetNewer ? `newer ` : ``}version (${res[name]}), but this may cause build errors.`
+        )
+      }
+    }
+  }
+  return res
+}
+
+const leadRE = /^(~|\^|>=?)/
+const rangeToVersion = r => r.replace(leadRE, '').replace(/x/g, '0')
+
+function tryGetNewerRange (r1, r2) {
+  const v1 = rangeToVersion(r1)
+  const v2 = rangeToVersion(r2)
+  if (semver.valid(v1) && semver.valid(v2)) {
+    return semver.gt(v1, v2) ? r1 : r2
+  }
+}
diff --git a/packages/@vue/cli/lib/util/resolveDeps.js b/packages/@vue/cli/lib/util/resolveDeps.js
deleted file mode 100644
index e69de29bb..000000000
diff --git a/packages/@vue/cli/lib/util/writeFileTree.js b/packages/@vue/cli/lib/util/writeFileTree.js
index d5d44846b..6036bb8f2 100644
--- a/packages/@vue/cli/lib/util/writeFileTree.js
+++ b/packages/@vue/cli/lib/util/writeFileTree.js
@@ -1,3 +1,2 @@
 module.exports = function writeFileTree (dir, files) {
-  console.log(files)
 }
diff --git a/packages/@vue/cli/package.json b/packages/@vue/cli/package.json
index 35854b17d..2a5fb3e6b 100644
--- a/packages/@vue/cli/package.json
+++ b/packages/@vue/cli/package.json
@@ -23,6 +23,7 @@
   "dependencies": {
     "chalk": "^2.3.0",
     "commander": "^2.12.2",
-    "inquirer": "^4.0.1"
+    "inquirer": "^4.0.1",
+    "semver": "^5.4.1"
   }
 }
diff --git a/yarn.lock b/yarn.lock
index f06304cb6..ec7018c96 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -412,6 +412,12 @@ dateformat@^1.0.11, dateformat@^1.0.12:
     get-stdin "^4.0.1"
     meow "^3.3.0"
 
+debug@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-3.1.0.tgz#5bb5a0672628b64149566ba16819e61518c67261"
+  dependencies:
+    ms "2.0.0"
+
 decamelize@^1.0.0, decamelize@^1.1.1, decamelize@^1.1.2:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/decamelize/-/decamelize-1.2.0.tgz#f6534d15148269b20352e7bee26f501f9a191290"
@@ -1049,6 +1055,10 @@ moment@^2.6.0:
   version "2.20.1"
   resolved "https://registry.yarnpkg.com/moment/-/moment-2.20.1.tgz#d6eb1a46cbcc14a2b2f9434112c1ff8907f313fd"
 
+ms@2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
+
 mute-stream@0.0.7:
   version "0.0.7"
   resolved "https://registry.yarnpkg.com/mute-stream/-/mute-stream-0.0.7.tgz#3075ce93bc21b8fab43e1bc4da7e8115ed1e7bab"