.eslintrc.json

{
    "env": {
        "browser": true,
        "es2021": true
    },
    "extends": [
        "eslint:recommended",
        "plugin:@typescript-eslint/recommended"
    ],
    "parser": "@typescript-eslint/parser",
    "parserOptions": {
        "ecmaVersion": "latest",
        "sourceType": "module",
        "project": "./tsconfig.json",
        "extraFileExtensions": [".svelte"]
    },
    "plugins": [
        "@typescript-eslint"
    ],
    "rules": {
        "indent": [
            "error",
            4
        ],
        "linebreak-style": [
            "error",
            "unix"
        ],
        "semi": [
            "error",
            "always"
        ]
    },
    "ignorePatterns": ["static/**"],
    "overrides": [
        {
            "files": ["*.svelte"],
            "parser": "svelte-eslint-parser",

            // "Parse" the `<script>` in `.svelte` as TypeScript by adding the following configuration.
            "parserOptions": {
                "parser": "@typescript-eslint/parser"
            }
        }
    ]
}