TS1259

Module can only be default-imported using the 'esModuleInterop' flag

Broken Code ❌

main.ts
import api from 'api';
tsconfig.json
{
  "compilerOptions": {
    "lib": ["dom", "es6"],
    "module": "commonjs",
    "moduleResolution": "node",
    "outDir": "dist",
    "rootDir": "src",
    "target": "es6"
  }
}

Fixed Code ✔️

tsconfig.json
{
  "compilerOptions": {
    "esModuleInterop": true,
    "lib": ["dom", "es6"],
    "module": "commonjs",
    "moduleResolution": "node",
    "outDir": "dist",
    "rootDir": "src",
    "target": "es6"
  }
}

Note: You can enable the 'esModuleInterop' flag also via the CLI:

tsc main.ts --esModuleInterop