I use a lib react-international-phone for phone input integration and it exposes UsePhoneInputConfig type, which looks like this,

type UsePhoneInputConfig = {
  onChange?: (data: { phone: string }) => void;
};

Now in my wrapper component over this lib, i’ve handleOnChange, which calls onChange prop, and is assigned to the function type from the lib.

  const handleOnChange: UsePhoneInputConfig['onChange'] = useCallback((data) => {
    onChange(data.phone);
  }, [onChange]);

And I was expecting the data type to be the object { phone: string }, but it says Parameter 'data' implicitly has an 'any' type.ts(7006), when I make the onChange a required type from UsePhoneInputConfig, it infers the type properly.

Here is my tsconfig.json

{
  "compilerOptions": {
    "lib": ["dom", "dom.iterable", "esnext"],
    "allowJs": true,
    "skipLibCheck": true,
    "strict": true,
    "noEmit": true,
    "esModuleInterop": true,
    "module": "esnext",
    "moduleResolution": "bundler",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "jsx": "preserve",
    "incremental": true,
    "downlevelIteration": true,
    "target": "ES2021",
    "plugins": [
      {
        "name": "next"
      }
    ],
    "paths": {
      "@/*": ["./src/*"],
      "@test/*": ["./test/*"],
    }
  },
  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
  "exclude": ["node_modules"]
}

Note: With typescript lang demo it does work properly, and not sure which tsconfig options is making this issue.