# vue-codemod

⚠️Attention: This repo is forked from https://github.com/vuejs/vue-codemod (opens new window).

vue-codemod is a Vue2 to Vue3 migration tool, which can directly upgrade most of the Vue2 syntax to Vue3 syntax. With vue-codemod transformation and a small amount of manual modification, users can complete the smooth migration from Vue2 to Vue3.

# Transformation Rates


Manually Upgraded: Number of patterns require manually upgrade

Auto Upgraded: Number of patterns upgraded by vue-codemod

No. Project Manually Upgraded Auto Upgraded Transformation Rates
1 vue2-element-touzi-admin (opens new window) 8 63 88.73%
2 vue-web-os (opens new window) 19 19 50.00%
3 amKnow (opens new window) 10 30 75.00%
4 vue-template (opens new window) 61 28 31.46%
5 coreui-free-vue-admin-template (opens new window) 4 63 94.03%
6 vue-weixin (opens new window) 1 54 98.19%
7 vue-WeChat (opens new window) 9 35 79.55%
8 vue2-management-platform (opens new window) 2 11 84.62%
9 vue-netease-music (opens new window) 18 37 67.27%
10 Mall-Vue (opens new window) 2 26 92.86%
11 vue-demo-kugou (opens new window) 4 13 76.47%
12 codemod-demo (opens new window) 0 24 100%

# Getting Started

# Installation

npm/yarn install is recommended. Users can also try beta version from GitHub

# Install from npm/yarn

npm install @originjs/vue-codemod -g
// or
yarn global add @originjs/vue-codemod

# Install form GitHub

  1. Clone from dev
git clone https://github.com/originjs/vue-codemod
  1. Install Dependencies
cd vue-codemod
npm install
// or
yarn install
  1. Install vue-codemod Globally
npm run build
npm install . -g
// or
yarn run build
yarn global add .

# Usage

vue-codemod consists of different migration rules. Those rules are defined in transformation/index.ts and vue-transformation/index.ts.

npx vue-codemod <path> -t/-a [transformation params][...additional options]
  1. <path> indicates the path of execution, which can be files and folders
  2. -a means executing all rules.
  3. -t means executing one specific rule (Conflicts with -a). When -t is used, parameter is required.

# Execute All Rules

npx vue-codemod src -a

src indicates the path of execution. -a means executing all rules.

# Execute Specific Rule

npx vue-codemod src -t new-global-api

src indicates the path of execution. -t new-global-api means only executing the rule of new-global-api .

Here is the detailed rule list.

# Output Format

npx vue-codemod src -a -f log

The -f option is used to specify the output format. The optional parameters are table, detail,log. If no parameters are specified, the default is table.

table : output the executed rules as a table

detail : list transformed files for each rule

log : output a report in the form of log file Here is a sample output of -f table:

║ Rule Names                    │ Count ║
║ new-component-api             │   1   ║
║ new-global-api                │   1   ║
║ vue-router-v4                 │   1   ║
║ vuex-v4                       │   1   ║
║ new-directive-api             │   1   ║
║ remove-vue-set-and-delete     │   2   ║
║ rename-lifecycle              │   2   ║
║ add-emit-declarations         │   1   ║
║ tree-shaking                  │   1   ║
║ slot-attribute                │   1   ║
║ slot-default                  │   1   ║
║ slot-scope-attribute          │   1   ║
║ v-for-template-key            │   2   ║
║ v-else-if-key                 │   3   ║
║ transition-group-root         │   1   ║
║ v-for-v-if-precedence-changed │   1   ║
║ remove-listeners              │   1   ║
║ remove-v-on-native            │   1   ║

# Manual Migration Guide

During the operation of vue-codemod, the patterns that need to be manually upgraded will be identified and printed to the console as an object (will create a log file if -f log is declared). For more details, please refer to Manual Migration Guide.

Here is the example:

The list that you need to migrate your codes mannually:
index: 1
  path: 'src/main.js',
  position: '[33,0]',
  name: 'remove Vue(global api)',
  suggest: "The rule of thumb is any APIs that globally mutate Vue's behavior are now moved to the app instance.",
  website: 'https://v3.vuejs.org/guide/migration/global-api.html#a-new-global-api-createapp'

# Help

npx vue-codemod --help


npx vue-codemod --help
Usage: vue-codemod [file pattern]
  -t, --transformation        Name or path of the transformation module [string]
  -p, --params                Custom params to the transformation
  -a, --runAllTransformation  run all transformation module            [boolean]
  -f, --reportFormatter       Specify an output report formatter
                                                    [string] [default: "detail"]
  -h, --help                  Show help                                [boolean]
  -v, --version               Show version number                      [boolean]
  npx vue-codemod ./src -a                  Run all rules to convert all
                                            relevant files in the ./src folder
  npx vue-codemod                           Run slot-attribute rule to convert
  ./src/components/HelloWorld.vue -t        HelloWorld.vue

# Migrating from Vue2 to Vue3

  1. Run the -a command: npx vue-codemod <path> -a
  2. Manually migrate some cases which vue-codemod doesn't cover based on Manual Migration Guide.
  3. Make sure to use @vue/compat (opens new window) to build
  4. Serve the app in development mode, fix the runtime deprecation warnings

Note: even though most of the migration process can be automated, please be aware there might still be subtle differences between Vue3 and Vue2 runtime, and the codemods may have uncovered edge cases. Please double check before deploying your Vue3 app into production.

# Typical Migration Case

We forked vue2-element-touzi-admin (opens new window), and try to migrate it from Vue2 to Vue3 with vue-codemod, we have recorded every step of the operation, if you are interested, please see Typical Migration Case

# Rule List

Rule Names Descriptions or links
new-component-api https://v3.vuejs.org/guide/migration/global-api.html#a-new-global-api-createapp
vue-class-component-v8 https://github.com/vuejs/vue-class-component/issues/406
new-global-api https://v3.vuejs.org/guide/migration/global-api.html#a-new-global-api-createapp
vue-router-v4 https://next.router.vuejs.org/guide/migration/index.html#new-router-becomes-createrouter
vuex-v4 new Store (...) => createStore (...)
define-component Vue.extend (...) => defineComponent (...)
new-vue-to-create-app https://v3.vuejs.org/guide/migration/global-api.html#a-new-global-api-createapp
scoped-slots-to-slots https://v3.vuejs.org/guide/migration/slots-unification.html#overview
new-directive-api https://v3.vuejs.org/guide/migration/custom-directives.html#overview
remove-vue-set-and-delete https://v3.vuejs.org/guide/migration/introduction.html#removed-apis
rename-lifecycle https://v3.vuejs.org/guide/migration/introduction.html#other-minor-changes
add-emit-declaration https://v3.vuejs.org/guide/migration/emits-option.html#overview
tree-shaking https://v3.vuejs.org/guide/migration/global-api-treeshaking.html
v-model https://v3.vuejs.org/guide/migration/v-model.html#overview
render-to-resolveComponent https://v3.vuejs.org/guide/migration/render-function-api.html#registered-component
remove-contextual-h-from-render https://v3.vuejs.org/guide/migration/render-function-api.html#render-function-argument
remove-production-tip https://v3.vuejs.org/guide/migration/global-api.html#a-new-global-api-createapp
remove-trivial-root createApp ({ render: () => h (App) }) => createApp (App)
vue-as-namespace-import import Vue from "vue" => import * as Vue from "vue"
slot-attribute https://vuejs.org/v2/guide/components-slots.html#Deprecated-Syntax
slot-default If component tag did not contain a <slot> element, any content provided between its opening and closing tag would be discarded.
slot-scope-attribute https://vuejs.org/v2/guide/components-slots.html#Scoped-Slots-with-the-slot-scope-Attribute
v-for-template-key https://v3.vuejs.org/guide/migration/key-attribute.html#overview
v-else-if-key https://v3.vuejs.org/guide/migration/key-attribute.html#overview
transition-group-root https://v3.vuejs.org/guide/migration/transition-group.html#overview
v-bind-order-sensitive https://v3.vuejs.org/guide/migration/v-bind.html#overview
v-for-v-if-precedence-changed https://v3.vuejs.org/guide/migration/v-if-v-for.html#overview
remove-listeners https://v3.vuejs.org/guide/migration/listeners-removed.html#overview
v-bind-sync https://v3.vuejs.org/guide/migration/v-model.html#overview
remove-v-on-native https://v3.vuejs.org/guide/migration/v-on-native-modifier-removed.html#overview
router-link-event-tag https://next.router.vuejs.org/guide/migration/index.html#removal-of-event-and-tag-props-in-router-link
router-link-exact https://next.router.vuejs.org/guide/migration/index.html#removal-of-the-exact-prop-in-router-link
router-view-keep-alive-transition https://next.router.vuejs.org/guide/migration/index.html#router-view-keep-alive-and-transition

# Post Transformation

  • Running transformations will generally ruin the formatting of your files. A recommended way to solve that problem is by using Prettier (opens new window) or eslint --fix.
  • Even after running prettier its possible to have unnecessary new lines added/removed. This can be solved by ignoring white spaces while staging the changes in git.
git diff --ignore-blank-lines | git apply --cached