From 46166fb6400b9b4399b055fd8cdcfdecb4c1ef0c Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Tue, 6 Feb 2018 16:01:58 -0500
Subject: [PATCH] fix: handle vue invoke config merging for existing files

close #788
---
 .../@vue/cli-test-utils/createTestProject.js  |  8 +-
 packages/@vue/cli/__tests__/Generator.spec.js | 43 ++---------
 packages/@vue/cli/__tests__/invoke.spec.js    | 73 +++++++++++++++++-
 packages/@vue/cli/acorn-test.js               | 54 +++++++++++++
 packages/@vue/cli/lib/Creator.js              |  5 +-
 packages/@vue/cli/lib/Generator.js            | 39 +++++++---
 packages/@vue/cli/lib/GeneratorAPI.js         |  7 +-
 packages/@vue/cli/lib/invoke.js               | 14 ++--
 .../lib/util/__tests__/extendJSConfig.spec.js | 59 +++++++++++++++
 packages/@vue/cli/lib/util/configMap.js       | 37 ---------
 .../@vue/cli/lib/util/configTransforms.js     | 75 +++++++++++++++++++
 packages/@vue/cli/lib/util/extendJSConfig.js  | 60 +++++++++++++++
 packages/@vue/cli/package.json                |  2 +
 yarn.lock                                     | 17 ++++-
 14 files changed, 386 insertions(+), 107 deletions(-)
 create mode 100644 packages/@vue/cli/acorn-test.js
 create mode 100644 packages/@vue/cli/lib/util/__tests__/extendJSConfig.spec.js
 delete mode 100644 packages/@vue/cli/lib/util/configMap.js
 create mode 100644 packages/@vue/cli/lib/util/configTransforms.js
 create mode 100644 packages/@vue/cli/lib/util/extendJSConfig.js

diff --git a/packages/@vue/cli-test-utils/createTestProject.js b/packages/@vue/cli-test-utils/createTestProject.js
index 7a33c62ee9..74cb4c8fa3 100644
--- a/packages/@vue/cli-test-utils/createTestProject.js
+++ b/packages/@vue/cli-test-utils/createTestProject.js
@@ -4,6 +4,7 @@ const execa = require('execa')
 const { promisify } = require('util')
 const readFile = promisify(fs.readFile)
 const writeFile = promisify(fs.writeFile)
+const rmFile = promisify(fs.unlink)
 const mkdirp = promisify(require('mkdirp'))
 
 module.exports = function createTestProject (name, preset, cwd) {
@@ -25,6 +26,10 @@ module.exports = function createTestProject (name, preset, cwd) {
     return mkdirp(dir).then(() => writeFile(targetPath, content))
   }
 
+  const rm = file => {
+    return rmFile(path.resolve(projectRoot, file))
+  }
+
   const run = (command, args) => {
     [command, ...args] = command.split(/\s+/)
     if (command === 'vue-cli-service') {
@@ -54,6 +59,7 @@ module.exports = function createTestProject (name, preset, cwd) {
     has,
     read,
     write,
-    run
+    run,
+    rm
   }))
 }
diff --git a/packages/@vue/cli/__tests__/Generator.spec.js b/packages/@vue/cli/__tests__/Generator.spec.js
index 392152492f..c4551a87f0 100644
--- a/packages/@vue/cli/__tests__/Generator.spec.js
+++ b/packages/@vue/cli/__tests__/Generator.spec.js
@@ -67,41 +67,6 @@ test('api: extendPackage function', async () => {
   })
 })
 
-test('api: extendPackage + { merge: false }', async () => {
-  const generator = new Generator('/', {
-    name: 'hello',
-    list: [1],
-    vue: {
-      foo: 1,
-      bar: 2
-    }
-  }, [{
-    id: 'test',
-    apply: api => {
-      api.extendPackage({
-        name: 'hello2',
-        list: [2],
-        vue: {
-          foo: 2,
-          baz: 3
-        }
-      }, { merge: false })
-    }
-  }])
-
-  await generator.generate()
-
-  const pkg = JSON.parse(fs.readFileSync('/package.json', 'utf-8'))
-  expect(pkg).toEqual({
-    name: 'hello2',
-    list: [2],
-    vue: {
-      foo: 2,
-      baz: 3
-    }
-  })
-})
-
 test('api: extendPackage merge dependencies', async () => {
   const generator = new Generator('/', {}, [
     {
@@ -292,7 +257,7 @@ test('api: onCreateComplete', () => {
         api.onCreateComplete(fn)
       }
     }
-  ], false, cbs)
+  ], cbs)
   expect(cbs).toContain(fn)
 })
 
@@ -333,9 +298,11 @@ test('extract config files', async () => {
         api.extendPackage(configs)
       }
     }
-  ], true)
+  ])
 
-  await generator.generate()
+  await generator.generate({
+    extractConfigFiles: true
+  })
 
   const json = v => JSON.stringify(v, null, 2)
   expect(fs.readFileSync('/vue.config.js', 'utf-8')).toMatch('module.exports = {\n  lintOnSave: true\n}')
diff --git a/packages/@vue/cli/__tests__/invoke.spec.js b/packages/@vue/cli/__tests__/invoke.spec.js
index 1b95447ff4..cf67caad47 100644
--- a/packages/@vue/cli/__tests__/invoke.spec.js
+++ b/packages/@vue/cli/__tests__/invoke.spec.js
@@ -1,4 +1,4 @@
-jest.setTimeout(10000)
+jest.setTimeout(12000)
 jest.mock('inquirer')
 
 const invoke = require('../lib/invoke')
@@ -22,13 +22,15 @@ async function assertUpdates (project) {
   const updatedPkg = JSON.parse(await project.read('package.json'))
   expect(updatedPkg.scripts.lint).toBe('vue-cli-service lint')
   expect(updatedPkg.devDependencies).toHaveProperty('lint-staged')
-  expect(updatedPkg.eslintConfig).toEqual({
-    extends: ['plugin:vue/essential', '@vue/airbnb']
-  })
   expect(updatedPkg.gitHooks).toEqual({
     'pre-commit': 'lint-staged'
   })
 
+  const eslintrc = JSON.parse(await project.read('.eslintrc'))
+  expect(eslintrc).toEqual({
+    extends: ['plugin:vue/essential', '@vue/airbnb']
+  })
+
   const lintedMain = await project.read('src/main.js')
   expect(lintedMain).toMatch(';') // should've been linted in post-generate hook
 }
@@ -58,3 +60,66 @@ test('invoke with prompts', async () => {
   await invoke(`eslint`, {}, project.dir)
   await assertUpdates(project)
 })
+
+test('invoke with existing files', async () => {
+  const project = await create(`invoke-existing`, {
+    useConfigFiles: true,
+    plugins: {
+      '@vue/cli-plugin-babel': {},
+      '@vue/cli-plugin-eslint': { config: 'base' }
+    }
+  })
+  // mock install
+  const pkg = JSON.parse(await project.read('package.json'))
+  pkg.devDependencies['@vue/cli-plugin-eslint'] = '*'
+  await project.write('package.json', JSON.stringify(pkg, null, 2))
+
+  // mock existing vue.config.js
+  await project.write('vue.config.js', `module.exports = { lintOnSave: false }`)
+
+  const eslintrc = JSON.parse(await project.read('.eslintrc'))
+  expect(eslintrc).toEqual({
+    extends: ['plugin:vue/essential', 'eslint:recommended']
+  })
+
+  await project.run(`${require.resolve('../bin/vue')} invoke eslint --config airbnb --lintOn save,commit`)
+
+  await assertUpdates(project)
+  const updatedVueConfig = await project.read('vue.config.js')
+  expect(updatedVueConfig).toMatch(`module.exports = { lintOnSave: true }`)
+})
+
+test('invoke with existing files (yaml)', async () => {
+  const project = await create(`invoke-existing`, {
+    useConfigFiles: true,
+    plugins: {
+      '@vue/cli-plugin-babel': {},
+      '@vue/cli-plugin-eslint': { config: 'base' }
+    }
+  })
+  // mock install
+  const pkg = JSON.parse(await project.read('package.json'))
+  pkg.devDependencies['@vue/cli-plugin-eslint'] = '*'
+  await project.write('package.json', JSON.stringify(pkg, null, 2))
+
+  const eslintrc = JSON.parse(await project.read('.eslintrc'))
+  expect(eslintrc).toEqual({
+    extends: ['plugin:vue/essential', 'eslint:recommended']
+  })
+
+  await project.rm(`.eslintrc`)
+  await project.write(`.eslintrc.yml`, `
+extends:
+  - 'plugin:vue/essential'
+  - 'eslint:recommended'
+  `.trim())
+
+  await project.run(`${require.resolve('../bin/vue')} invoke eslint --config airbnb`)
+
+  const updated = await project.read('.eslintrc.yml')
+  expect(updated).toMatch(`
+extends:
+  - 'plugin:vue/essential'
+  - '@vue/airbnb'
+`.trim())
+})
diff --git a/packages/@vue/cli/acorn-test.js b/packages/@vue/cli/acorn-test.js
new file mode 100644
index 0000000000..3e1b474543
--- /dev/null
+++ b/packages/@vue/cli/acorn-test.js
@@ -0,0 +1,54 @@
+const acorn = require('acorn')
+const walk = require('acorn/dist/walk')
+
+const ast = acorn.parse(`
+module.exports = {
+  lintOnSave: true,
+  css: {
+    loaderOptions: {
+      sass: {
+        data: 'foo'
+      }
+    }
+  },
+  pluginsOptions: {
+    foo: 'bar'
+  }
+}
+`)
+
+let exportsIdentifier = null
+
+walk.simple(ast, {
+  AssignmentExpression (node) {
+    if (
+      node.left.type === 'MemberExpression' &&
+      node.left.object.name === 'module' &&
+      node.left.property.name === 'exports'
+    ) {
+      if (node.right.type === 'ObjectExpression') {
+        augmentExports(node.right)
+      } else if (node.right.type === 'Identifier') {
+        // do a second pass
+        exportsIdentifier = node.right.name
+      }
+    }
+  }
+})
+
+if (exportsIdentifier) {
+  walk.simple(ast, {
+    VariableDeclarator (node) {
+      if (
+        node.id.name === exportsIdentifier &&
+        node.init.type === 'ObjectExpression'
+      ) {
+        augmentExports(node.init)
+      }
+    }
+  })
+}
+
+function augmentExports (node) {
+  console.log(node)
+}
diff --git a/packages/@vue/cli/lib/Creator.js b/packages/@vue/cli/lib/Creator.js
index 6c3f75178a..870d541c06 100644
--- a/packages/@vue/cli/lib/Creator.js
+++ b/packages/@vue/cli/lib/Creator.js
@@ -136,10 +136,11 @@ module.exports = class Creator {
       context,
       pkg,
       plugins,
-      preset.useConfigFiles,
       createCompleteCbs
     )
-    await generator.generate()
+    await generator.generate({
+      extractConfigFiles: preset.useConfigFiles
+    })
 
     // install additional deps (injected by generators)
     log(`📦  Installing additional dependencies...`)
diff --git a/packages/@vue/cli/lib/Generator.js b/packages/@vue/cli/lib/Generator.js
index a1f80ea97c..a9f35fbfe5 100644
--- a/packages/@vue/cli/lib/Generator.js
+++ b/packages/@vue/cli/lib/Generator.js
@@ -1,16 +1,17 @@
 const ejs = require('ejs')
 const slash = require('slash')
 const debug = require('debug')
-const configMap = require('./util/configMap')
 const GeneratorAPI = require('./GeneratorAPI')
 const sortObject = require('./util/sortObject')
 const writeFileTree = require('./util/writeFileTree')
+const configTransforms = require('./util/configTransforms')
 
 module.exports = class Generator {
-  constructor (context, pkg, plugins, extractConfigFiles, completeCbs = []) {
+  constructor (context, pkg, plugins, completeCbs = []) {
     this.context = context
     this.plugins = plugins
-    this.pkg = pkg
+    this.originalPkg = pkg
+    this.pkg = Object.assign({}, pkg)
     this.completeCbs = completeCbs
 
     // for conflict resolution
@@ -27,11 +28,14 @@ module.exports = class Generator {
       const api = new GeneratorAPI(id, this, options, rootOptions || {})
       apply(api, options, rootOptions)
     })
-    // extract configs from package.json into dedicated files.
-    this.extractConfigFiles(extractConfigFiles)
   }
 
-  async generate () {
+  async generate ({
+    extractConfigFiles = false,
+    checkExisting = false
+  } = {}) {
+    // extract configs from package.json into dedicated files.
+    this.extractConfigFiles(extractConfigFiles, checkExisting)
     // wait for file resolve
     await this.resolveFiles()
     // set package.json
@@ -41,21 +45,32 @@ module.exports = class Generator {
     await writeFileTree(this.context, this.files)
   }
 
-  extractConfigFiles (all) {
+  extractConfigFiles (extractAll, checkExisting) {
     const extract = key => {
-      if (configMap[key]) {
+      if (
+        configTransforms[key] &&
+        this.pkg[key] &&
+        // do not extract if the field exists in original package.json
+        !this.originalPkg[key]
+      ) {
         const value = this.pkg[key]
-        const { transform, filename } = configMap[key]
-        this.files[filename] = transform(value)
+        const transform = configTransforms[key]
+        const res = transform(
+          value,
+          checkExisting,
+          this.context
+        )
+        const { content, filename } = res
+        this.files[filename] = content
         delete this.pkg[key]
       }
     }
-    if (all) {
+    if (extractAll) {
       for (const key in this.pkg) {
         extract(key)
       }
     } else if (!process.env.VUE_CLI_TEST) {
-      // by default, extract vue.config.js
+      // by default, always extract vue.config.js
       extract('vue')
     }
   }
diff --git a/packages/@vue/cli/lib/GeneratorAPI.js b/packages/@vue/cli/lib/GeneratorAPI.js
index af3c86e3de..a825df262c 100644
--- a/packages/@vue/cli/lib/GeneratorAPI.js
+++ b/packages/@vue/cli/lib/GeneratorAPI.js
@@ -100,10 +100,9 @@ class GeneratorAPI {
    * Tool configuration fields may be extracted into standalone files before
    * files are written to disk.
    *
-   * @param {object} fields - Fields to merge.
-   * @param {object} [options] - pass { merge: false } to disable deep merging.
+   * @param {object | () => object} fields - Fields to merge.
    */
-  extendPackage (fields, options = { merge: true }) {
+  extendPackage (fields) {
     const pkg = this.generator.pkg
     const toMerge = isFunction(fields) ? fields(pkg) : fields
     for (const key in toMerge) {
@@ -117,7 +116,7 @@ class GeneratorAPI {
           value,
           this.generator.depSources
         )
-      } else if (!options.merge || !(key in pkg)) {
+      } else if (!(key in pkg)) {
         pkg[key] = value
       } else if (Array.isArray(value) && Array.isArray(existing)) {
         pkg[key] = existing.concat(value)
diff --git a/packages/@vue/cli/lib/invoke.js b/packages/@vue/cli/lib/invoke.js
index 1b79cf0fa2..5a8f8a922f 100644
--- a/packages/@vue/cli/lib/invoke.js
+++ b/packages/@vue/cli/lib/invoke.js
@@ -81,13 +81,15 @@ async function invoke (pluginName, options = {}, context = process.cwd()) {
     context,
     pkg,
     [plugin],
-    isTestOrDebug ? false : loadOptions().useConfigFiles,
     createCompleteCbs
   )
 
   log()
   logWithSpinner('🚀', `Invoking generator for ${id}...`)
-  await generator.generate()
+  await generator.generate({
+    extractConfigFiles: true,
+    checkExisting: true
+  })
 
   const newDeps = generator.pkg.dependencies
   const newDevDeps = generator.pkg.devDependencies
@@ -115,9 +117,11 @@ async function invoke (pluginName, options = {}, context = process.cwd()) {
   log(`   Successfully invoked generator for plugin: ${chalk.cyan(id)}`)
   if (!process.env.VUE_CLI_TEST && hasGit()) {
     const { stdout } = await execa('git', ['ls-files', '--exclude-standard', '--modified', '--others'])
-    log(`   The following files have been updated / added:\n`)
-    log(chalk.red(stdout.split(/\r?\n/g).map(line => `     ${line}`).join('\n')))
-    log()
+    if (stdout.trim()) {
+      log(`   The following files have been updated / added:\n`)
+      log(chalk.red(stdout.split(/\r?\n/g).map(line => `     ${line}`).join('\n')))
+      log()
+    }
   }
   log(`   You should review and commit the changes.`)
   log()
diff --git a/packages/@vue/cli/lib/util/__tests__/extendJSConfig.spec.js b/packages/@vue/cli/lib/util/__tests__/extendJSConfig.spec.js
new file mode 100644
index 0000000000..34d6ffdff4
--- /dev/null
+++ b/packages/@vue/cli/lib/util/__tests__/extendJSConfig.spec.js
@@ -0,0 +1,59 @@
+const extend = require('../extendJSConfig')
+
+test(`basic`, () => {
+  const value = {
+    foo: true,
+    css: {
+      modules: true
+    }
+  }
+  const source =
+`module.exports = {
+  foo: false,
+  css: {
+    modules: false
+  }
+}`
+  expect(extend(value, source)).toMatch(
+    `module.exports = {
+  foo: true,
+  css: {
+    modules: true
+  }
+}`
+  )
+})
+
+test(`adding new property`, () => {
+  const value = {
+    foo: true
+  }
+  const source =
+`module.exports = {
+  bar: 123
+}`
+  expect(extend(value, source)).toMatch(
+    `module.exports = {
+  bar: 123,
+  foo: true
+}`
+  )
+})
+
+test(`non direct assignment`, () => {
+  const value = {
+    foo: true
+  }
+  const source =
+`const config = {
+  bar: 123
+}
+module.exports = config`
+  expect(extend(value, source)).toMatch(
+    `const config = {
+  bar: 123,
+  foo: true
+}
+module.exports = config`
+  )
+})
diff --git a/packages/@vue/cli/lib/util/configMap.js b/packages/@vue/cli/lib/util/configMap.js
deleted file mode 100644
index e9a1d1be04..0000000000
--- a/packages/@vue/cli/lib/util/configMap.js
+++ /dev/null
@@ -1,37 +0,0 @@
-const stringifyJS = require('javascript-stringify')
-const json = value => JSON.stringify(value, null, 2)
-const js = value => `module.exports = ${stringifyJS(value, null, 2)}`
-
-module.exports = {
-  vue: {
-    filename: 'vue.config.js',
-    transform: js
-  },
-  babel: {
-    filename: '.babelrc',
-    transform: json
-  },
-  postcss: {
-    filename: '.postcssrc',
-    transform: json
-  },
-  eslintConfig: {
-    filename: '.eslintrc',
-    transform: json
-  },
-  jest: {
-    filename: 'jest.config.js',
-    transform: js
-  }
-
-  // these are less likely to be edited frequently
-
-  // browserslist: {
-  //   filename: '.browserslistrc',
-  //   transform: value => value.join('\n')
-  // },
-  // 'lint-staged': {
-  //   filename: '.lintstagedrc',
-  //   transform: json
-  // }
-}
diff --git a/packages/@vue/cli/lib/util/configTransforms.js b/packages/@vue/cli/lib/util/configTransforms.js
new file mode 100644
index 0000000000..5b82e78fe8
--- /dev/null
+++ b/packages/@vue/cli/lib/util/configTransforms.js
@@ -0,0 +1,75 @@
+const fs = require('fs')
+const path = require('path')
+const extendJSConfig = require('./extendJSConfig')
+const stringifyJS = require('javascript-stringify')
+
+function makeJSTransform (filename) {
+  return function transformToJS (value, checkExisting, context) {
+    const absolutePath = path.resolve(context, filename)
+    if (checkExisting && fs.existsSync(absolutePath)) {
+      return {
+        filename,
+        content: extendJSConfig(value, fs.readFileSync(absolutePath, 'utf-8'))
+      }
+    } else {
+      return {
+        filename,
+        content: `module.exports = ${stringifyJS(value, null, 2)}`
+      }
+    }
+  }
+}
+
+function makeJSONTransform (filename) {
+  return function transformToJSON (value, checkExisting, context) {
+    let existing = {}
+    const absolutePath = path.resolve(context, filename)
+    if (checkExisting && fs.existsSync(absolutePath)) {
+      existing = JSON.parse(fs.readFileSync(absolutePath, 'utf-8'))
+    }
+    value = Object.assign(existing, value)
+    return {
+      filename,
+      content: JSON.stringify(value, null, 2)
+    }
+  }
+}
+
+function makeMutliExtensionJSONTransform (filename) {
+  return function transformToMultiExtensions (value, checkExisting, context) {
+    if (!checkExisting) {
+      return makeJSONTransform(filename)(value, checkExisting, context)
+    }
+    const absolutePath = path.resolve(context, filename)
+    if (fs.existsSync(absolutePath)) {
+      return makeJSONTransform(filename)(value, checkExisting, context)
+    } else if (fs.existsSync(`${absolutePath}.json`)) {
+      return makeJSONTransform(`${filename}.json`)(value, checkExisting, context)
+    } else if (fs.existsSync(`${absolutePath}.js`)) {
+      return makeJSTransform(`${filename}.js`)(value, checkExisting, context)
+    } else if (fs.existsSync(`${absolutePath}.yaml`)) {
+      return transformYAML(value, `${filename}.yaml`, fs.readFileSync(`${absolutePath}.yaml`, 'utf-8'))
+    } else if (fs.existsSync(`${absolutePath}.yml`)) {
+      return transformYAML(value, `${filename}.yml`, fs.readFileSync(`${absolutePath}.yml`, 'utf-8'))
+    } else {
+      return makeJSONTransform(filename)(value, false, context)
+    }
+  }
+}
+
+function transformYAML (value, filename, source) {
+  const yaml = require('js-yaml')
+  const existing = yaml.safeLoad(source)
+  return {
+    filename,
+    content: yaml.safeDump(Object.assign(existing, value))
+  }
+}
+
+module.exports = {
+  vue: makeJSTransform('vue.config.js'),
+  babel: makeJSONTransform('.babelrc'),
+  postcss: makeMutliExtensionJSONTransform('.postcssrc'),
+  eslintConfig: makeMutliExtensionJSONTransform('.eslintrc'),
+  jest: makeJSTransform('jest.config.js')
+}
diff --git a/packages/@vue/cli/lib/util/extendJSConfig.js b/packages/@vue/cli/lib/util/extendJSConfig.js
new file mode 100644
index 0000000000..fbf77336ea
--- /dev/null
+++ b/packages/@vue/cli/lib/util/extendJSConfig.js
@@ -0,0 +1,60 @@
+module.exports = function extendJSConfig (value, source) {
+  const recast = require('recast')
+  const stringifyJS = require('javascript-stringify')
+
+  let exportsIdentifier = null
+
+  const ast = recast.parse(source)
+
+  recast.types.visit(ast, {
+    visitAssignmentExpression ({ node }) {
+      if (
+        node.left.type === 'MemberExpression' &&
+        node.left.object.name === 'module' &&
+        node.left.property.name === 'exports'
+      ) {
+        if (node.right.type === 'ObjectExpression') {
+          augmentExports(node.right)
+        } else if (node.right.type === 'Identifier') {
+          // do a second pass
+          exportsIdentifier = node.right.name
+        }
+        return false
+      }
+    }
+  })
+
+  if (exportsIdentifier) {
+    recast.types.visit(ast, {
+      visitVariableDeclarator ({ node }) {
+        if (
+          node.id.name === exportsIdentifier &&
+          node.init.type === 'ObjectExpression'
+        ) {
+          augmentExports(node.init)
+        }
+        return false
+      }
+    })
+  }
+
+  function augmentExports (node) {
+    const valueAST = recast.parse(`(${stringifyJS(value, null, 2)})`)
+    const props = valueAST.program.body[0].expression.properties
+    const existingProps = node.properties
+    for (const prop of props) {
+      const existing = existingProps.findIndex(p => {
+        return !p.computed && p.key.name === prop.key.name
+      })
+      if (existing > -1) {
+        // replace
+        existingProps[existing].value = prop.value
+      } else {
+        // append
+        existingProps.push(prop)
+      }
+    }
+  }
+
+  return recast.print(ast).code
+}
diff --git a/packages/@vue/cli/package.json b/packages/@vue/cli/package.json
index 00ac6160bb..0f33c102ae 100644
--- a/packages/@vue/cli/package.json
+++ b/packages/@vue/cli/package.json
@@ -38,10 +38,12 @@
     "inquirer": "^4.0.1",
     "isbinaryfile": "^3.0.2",
     "javascript-stringify": "^1.6.0",
+    "js-yaml": "^3.10.0",
     "klaw-sync": "^3.0.2",
     "lodash.clonedeep": "^4.5.0",
     "minimist": "^1.2.0",
     "mkdirp": "^0.5.1",
+    "recast": "^0.13.0",
     "resolve": "^1.5.0",
     "rimraf": "^2.6.2",
     "semver": "^5.4.1",
diff --git a/yarn.lock b/yarn.lock
index f2b66e21da..f592e236e0 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1046,7 +1046,7 @@ assign-symbols@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/assign-symbols/-/assign-symbols-1.0.0.tgz#59667f41fadd4f20ccbc2bb96b8d4f7f78ec0367"
 
-ast-types@0.x.x:
+ast-types@0.10.1, ast-types@0.x.x:
   version "0.10.1"
   resolved "https://registry.yarnpkg.com/ast-types/-/ast-types-0.10.1.tgz#f52fca9715579a14f841d67d7f8d25432ab6a3dd"
 
@@ -3573,7 +3573,7 @@ esprima@^2.6.0:
   version "2.7.3"
   resolved "https://registry.yarnpkg.com/esprima/-/esprima-2.7.3.tgz#96e3b70d5779f6ad49cd032673d1c312767ba581"
 
-esprima@^4.0.0:
+esprima@^4.0.0, esprima@~4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/esprima/-/esprima-4.0.0.tgz#4499eddcd1110e0b218bacf2fa7f7f59f55ca804"
 
@@ -5806,7 +5806,7 @@ js-tokens@^3.0.0, js-tokens@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/js-tokens/-/js-tokens-3.0.2.tgz#9866df395102130e38f7f996bceb65443209c25b"
 
-js-yaml@^3.4.3, js-yaml@^3.7.0, js-yaml@^3.8.1, js-yaml@^3.9.0, js-yaml@^3.9.1:
+js-yaml@^3.10.0, js-yaml@^3.4.3, js-yaml@^3.7.0, js-yaml@^3.8.1, js-yaml@^3.9.0, js-yaml@^3.9.1:
   version "3.10.0"
   resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.10.0.tgz#2e78441646bd4682e963f22b6e92823c309c62dc"
   dependencies:
@@ -7959,7 +7959,7 @@ pretty@2.0.0:
     extend-shallow "^2.0.1"
     js-beautify "^1.6.12"
 
-private@^0.1.6, private@^0.1.7:
+private@^0.1.6, private@^0.1.7, private@~0.1.5:
   version "0.1.8"
   resolved "https://registry.yarnpkg.com/private/-/private-0.1.8.tgz#2381edb3689f7a53d653190060fcf822d2f368ff"
 
@@ -8280,6 +8280,15 @@ realpath-native@^1.0.0:
   dependencies:
     util.promisify "^1.0.0"
 
+recast@^0.13.0:
+  version "0.13.0"
+  resolved "https://registry.yarnpkg.com/recast/-/recast-0.13.0.tgz#a343a394a37d24668d700f88ed04b8d2c314d40d"
+  dependencies:
+    ast-types "0.10.1"
+    esprima "~4.0.0"
+    private "~0.1.5"
+    source-map "~0.6.1"
+
 recursive-readdir@^2.1.0:
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/recursive-readdir/-/recursive-readdir-2.2.1.tgz#90ef231d0778c5ce093c9a48d74e5c5422d13a99"