tsconfig.json

{
  "compilerOptions": {
    "allowJs": false,
    "checkJs": false,
    "allowSyntheticDefaultImports": true,
    "declaration": true, // emits ".d.ts" files
    "declarationMap": true, // emits ".map" files
    "esModuleInterop": true,
    "experimentalDecorators": true,
    "forceConsistentCasingInFileNames": true,
    "jsx": "react", // ts-jest relies on this
    "lib": ["es7"],
    // "module": "commonjs", // we'll still transpile as CJS to enable use of ts-node locally. We should define a "source" field to allow webpack/rollup to still treeshake
    "module": "ESNext", // must be ES Module output so rollup etc can take advantage
    "moduleResolution": "node",
    "noFallthroughCasesInSwitch": true,
    "noImplicitAny": true,
    "noImplicitReturns": true,
    "noUnusedLocals": false,
    "noUnusedParameters": false,
    "plugins": [],
    "removeComments": true,
    "resolveJsonModule": true,
    "skipLibCheck": true,
    "sourceMap": true,
    "strictNullChecks": true,
    "target": "es2017", // to allow use of Object.values
    // --- base
    "incremental": true,
    "tsBuildInfoFile": "dist/.tsbuildinfo",
    "rootDir": "src",
    "outDir": "dist"
  },
  "include": ["src/**/*", "./typings/index.d.ts"],
  "exclude": [
    "**/__tests__/**/*",
    "**/__mocks__/**/*",
    "**/*.pre-*.*",
    "**/*.post-*.*",
    "**/*.deleteable.*",
    "**/*.ignore.*",
    "**/*.skip.*",
    "**/dist",
  ]
}