tsconfig.lib.json

{
    "extends": "./tsconfig.json",
    "compilerOptions": {
        "allowJs": false,       // Necessary to make "declaration": true work
        "declaration": true,    // We want .d.ts files
        "declarationMap": true, // We want .d.ts files for source maps for editor integration
        "rootDir": ".",
        "outDir": "lib",
        "baseUrl": "."
    }
}