Upgrade Vue 2.6 - To 2.7

If you used @vue/runtime-dom or @vue/runtime-core types, remove them. Update vetur to latest:

// webpack.config.js module.exports = module: rules: [ test: /\.vue$/, loader: 'vue-loader', , ], , plugins: [ new (require('vue-loader')).VueLoaderPlugin(), ], ; If using vue-cli (v4 or v5), no action is needed – it handles the update automatically. Vue 2.7 ships with its own TypeScript declarations. Remove any custom shims-vue.d.ts that redeclare .vue modules. upgrade vue 2.6 to 2.7

npm install vue-loader@^15.10.0 --save-dev For Webpack config, ensure .vue files are handled correctly: Remove any custom shims-vue

// vue.config.js (vue-cli) module.exports = chainWebpack: config => config.module .rule('vue') .use('vue-loader') .tap(options => ( ...options, reactivityTransform: true, )); , ; Then write: console.log('mounted')) return count &lt

- this.$scopedSlots.header(data) + this.$slots.header(data) Functional components using the functional: true option or <template functional> still work, but the performance benefit is minimal. Consider migrating to normal components. 4. props validation Default factory functions no longer have access to this . Use arrow functions or external helpers. New Features to Start Using Composition API (no extra import) <script> import ref, onMounted from 'vue' export default setup() const count = ref(0) onMounted(() => console.log('mounted')) return count

</script> <script setup> import ref from 'vue' const count = ref(0) </script> <template> <button @click="count++"> count </button> </template> Optional chaining and nullish coalescing <template> <div> user?.address?.city ?? 'Unknown' </div> </template> Reactivity Transform (opt-in) Enable via vue-loader config:

upgrade vue 2.6 to 2.7