tsconfig.json

{
  "compilerOptions": {
    "baseUrl": ".",

    // don't write output, only perform type checking
    "noEmit": true,

    // don't allow un-used variables
    "noUnusedLocals": true,

    // Enables all strict type checking options.
    "strict": true,

    // Use commonjs for node, overridden in webpack to keep import statements
    // to maintain support for things like `await import()`
    "module": "commonjs",

    // Allows default imports from modules with no default export. This does not affect code emit, just type checking.
    // We have to enable this option explicitly since `esModuleInterop` doesn't enable it automatically when ES2015 or
    // ESNext module format is used.
    "allowSyntheticDefaultImports": true,

    // Node 8 should support everything output by esnext, we override this
    // in webpack with loader-level compiler options
    "target": "esnext",

    // Support .tsx files and transform JSX into calls to React.createElement
    "jsx": "react",

    // Emits __importStar and __importDefault helpers for runtime babel ecosystem compatibility.
    "esModuleInterop": true,

    // Resolve modules in the same way as Node.js. Aka make `require` works the
    // same in TypeScript as it does in Node.js.
    "moduleResolution": "node",

    // Disallow inconsistently-cased references to the same file.
    "forceConsistentCasingInFileNames": true,

    // Disable the breaking keyof behaviour introduced in TS 2.9.2 until EUI is updated to support that too
    "keyofStringsOnly": true,

    // enables "core language features"
    "lib": [
      // ESNext auto includes previous versions all the way back to es5
      "esnext",
      // includes support for browser APIs
      "dom"
    ]
  },
  "include": [
    "./src/**/*",
    "./src-docs/**/*"
  ]
}