tsconfig.json

{
    "compilerOptions": {
        "rootDir": "./source",
        "outDir": "./www",
        "target": "es5",
        "module": "commonjs",
        "moduleResolution": "node",
        "allowSyntheticDefaultImports": true,
        "declaration": true,
        "declarationMap": true,
        "importHelpers": true,
        "alwaysStrict": true,
        "sourceMap": false,
        "forceConsistentCasingInFileNames": true,
        "noFallthroughCasesInSwitch": true,
        "noImplicitReturns": true,
        "noUnusedLocals": true,
        "noUnusedParameters": true,
        "noImplicitAny": false,
        "noImplicitThis": false,
        "strictNullChecks": false,
        "lib": [
            "es2015",
            "es2016",
            "es2017",
            "esnext"
        ],
        "typeRoots": [
            "types"
        ],
        "baseUrl": "types"
    },
    "include": [
        "source/**/*",
        "__tests__/**/*"
    ]
}