tsconfig.json

{
  "extends": "@tsconfig/svelte/tsconfig.json",
  "compilerOptions": {
    "target": "ESNext",
    "useDefineForClassFields": true,
    "module": "ESNext",
    "resolveJsonModule": true,
    /**
     * Typecheck JS in `.svelte` and `.js` files by default.
     * Disable checkJs if you'd like to use dynamic types in JS.
     * Note that setting allowJs false does not prevent the use
     * of JS in `.svelte` files.
     */
    "allowJs": true,
    "checkJs": true,
    "isolatedModules": true,
    "moduleDetection": "force",
    "strict": true,
    "noFallthroughCasesInSwitch": true,
    "noImplicitAny": true,
    "noImplicitReturns": true,
    "noUncheckedIndexedAccess": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noImplicitOverride": true,
    "forceConsistentCasingInFileNames": true
  },
  "include": ["src/**/*.ts", "src/**/*.js", "src/**/*.svelte"],
  "references": [{ "path": "./tsconfig.node.json" }]
}