ESLint: Parsing error: Unexpected token :

Issue

Hi everyone I am migrating my vue3 project from js to typescript, I run into this problem :

Here is my code in .vue file

<script setup lang="ts">
const toto = (msg: string) => {
  console.log(msg)
}
</script>

And here is my eslintrc.js

module.exports = {
  'env': {
    'browser': true,
    'es2021': true
  },
  'extends': [
    'eslint:recommended',
    'plugin:vue/vue3-essential'
  ],
  'parserOptions': {
    'ecmaVersion': 13,
    'sourceType': 'module'
  },
  'plugins': [
    'vue'
  ],
  'rules': {
    'vue/multi-word-component-names': 'off',
    'vue/object-curly-spacing': [2, 'always'],
    'vue/html-closing-bracket-spacing': [2, {
      'selfClosingTag': 'always'
    }],
    'vue/max-attributes-per-line': [2, {
      'singleline': {
        'max': 1
      },
      'multiline': {
        'max': 1
      }
    }],
    'semi': [2, 'never']
  }
}

Solution

You need to configure eslint to support typescript as eslint doesn't support it out of the box. First, you need to install @typescript-eslint/parser and then @typescript-eslint/eslint-plugin. Once you have installed these, update your config as follows-

module.exports = {
    'env': {
        'browser': true,
        'es2021': true,
        node: true
    },
    'extends': [
        'eslint:recommended',
        'plugin:vue/vue3-essential'
    ],
    'parserOptions': {
        'ecmaVersion': 12,
        'sourceType': 'module',
        parser: '@typescript-eslint/parser'
    },
    'plugins': [
        'vue',
        '@typescript-eslint'
    ],
    'rules': {
        'vue/multi-word-component-names': 'off',
        'vue/object-curly-spacing': [2, 'always'],
        'vue/html-closing-bracket-spacing': [2, {
            'selfClosingTag': 'always'
        }],
        'vue/max-attributes-per-line': [2, {
            'singleline': {
                'max': 1
            },
            'multiline': {
                'max': 1
            }
        }],
        'semi': [2, 'never']
    }
}

Answered By - RHN CHN