tsconfig.service-worker.json

{
    "compilerOptions": {
        "target": "es6",
        "module": "es6",
        "lib": ["es6", "webworker", "ES2021.String"],

        /* Strict Type-Checking Options */
        /* Enable all strict type-checking options. */
        "strictNullChecks": true,

        "moduleResolution": "node",
        "outDir": "build",
        "composite": true,
        "sourceMap": true,
        "allowSyntheticDefaultImports": true,
        "types": ["chrome", "node", "firefox-webext-browser"]
    },
    "include": ["src/extension_service_worker.ts"]
}