tsconfig.json

{
  "compilerOptions": {
    "target": "esnext",
    "module": "esnext",
    // Search under node_modules for non-relative imports.
    "moduleResolution": "node",
    // Enable strictest settings like strictNullChecks & noImplicitAny.
    "strict": true,
    // Disallow features that require cross-file information for emit.
    "isolatedModules": true,
    // Support Preact
    "jsx": "react",
    "jsxFactory": "h",
    // Allow processing & inferring types from .js files.
    // (Needed for ts-jest to run code from NPM module JSX-DOM.)
    "allowJs": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true
  },
  "include": ["src_js"],

  // Most ts-node options can be specified here using their programmatic names.
  "ts-node": {
    // It is faster to skip typechecking.
    "transpileOnly": true,
    "files": true,
    "compilerOptions": {
      // compilerOptions specified here will override those declared above,
      // but *only* in ts-node.
      "lib": ["esnext"],
      "module": "commonjs",
      "target": "esnext",

      "esModuleInterop": true,
      "skipLibCheck": true,
      "forceConsistentCasingInFileNames": true
    }
  }
}