tsconfig.json

{
  "extends": "./node_modules/gts/tsconfig-google.json",
  "compilerOptions": {
    "allowSyntheticDefaultImports": true,
    "alwaysStrict": true,
    "esModuleInterop": true,
    "experimentalDecorators": true,
    "lib": ["ESNext"],
    "module": "ES2020",
    "moduleResolution": "Node",
    "newLine": "lf",
    "noImplicitAny": true,
    "noImplicitThis": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "outDir": "build",
    "rootDir": ".",
    "strictBindCallApply": true,
    "strictFunctionTypes": true,
    "strictNullChecks": true,
    "strictPropertyInitialization": true,
    "stripInternal": true,
    "suppressExcessPropertyErrors": true,
    "suppressImplicitAnyIndexErrors": true,
    "target": "es2019",

    "importHelpers": true // canary: will cause runtime error if `tslib` is necessary
  },
  "include": [
    "src/**.ts",
    "test/**.ts"
  ]
}