react-redux-typescript-boilerplate | bare minimum frontend boilerplate with React | Frontend Framework library

Your thinking is correct with regards to what the code is doing.

1. Yes, the compiler infers whether it refers to the type alias or the namespace based on the usage.

For example: https://github.com/rokoroku/react-redux-typescript-boilerplate/blob/master/src/app/components/TodoList/index.tsx#L10

Here, TodoActions is used as a type, so the compiler knows that it refers to the exported type alias.

Another example: https://github.com/rokoroku/react-redux-typescript-boilerplate/blob/master/src/app/reducers/todos.ts#L16

Here, TodoActions.Type.ADD_TODO is used to create a property, so the compiler, again, knows that it refers to the namespace.

You can actually see this if you hover over the identifier in VS Code:

1. and 3.) It can be a little confusing at first, but this is intended behavior. I personally would avoid it though, as it can cause unnecessary confusion.

The following article explains the exact question you have: https://www.typescriptlang.org/docs/handbook/declaration-files/deep-dive.html