Coding styles

1. Always add a return type to a function definition.

   This is something that the compiler is able to figure out even we don't add a return type. However, by adding the return type, it's more human-readable.

2. Remove unused import statements

3. Remove unused variables, arguments.

4. Always format code with prettier

5. Catch error from async function

References

• Getting Started - Linting your TypeScript Codebase

• The future of TypeScript on ESLint