I'd highly recommend using a type system like Flow to enumerate the shape of possible actions the store should support. This brings numerous advantages:

1. You can use strings for action types, no more need to import constants.

2. No need for action creators for simple actions, you can just create the action object inline and Flow will validate its shape.

3. You can be sure that reducers are unpacking properties that actually exist from the actions.

In other words, your example could simply be:

    // types.js
    type Action =
      | { type: 'ADD_TODO', text: string }

    // TodoList.js
    dispatch({ type: 'ADD_TODO', text })

...and Flow would confirm at 'compile time' that it matches the contract dispatch expects.

This approach has scaled up extremely well for me and no longer feels verbose.