Option to show expanded type instead of type alias on hover

[vishwa-raj]

Can we have an option to show the expanded types instead of the type alias on hover ?

If one uses type aliases to shorten and reuse type hint definitions and there are nested type alias definitions across files, then it becomes very difficult to track down the actual type values.

[judej]

This is similar to #562. Will look at adding a toggle depending on upvotes

[jakebailey]

See my comment here: #562 (comment)

This current behavior is pretty deliberate.

[vishwa-raj]

@jakebailey Yes, I did realize that this behavior is deliberate after going through other related issues (though missed 562).
Hence I requested to make it optional instead of a complete change.

@judej Thanks. Waiting for sufficient upvotes then on 562.

[jakebailey]

This issue (that you opened) would be the place to vote; #562 actually turned out to reveal a bug and has since been fixed.

[vishwa-raj]

@jakebailey Ah, thanks for clarifying.

[vishwa-raj]

@jakebailey I just realised that type aliases do expand on hover or in suggestions when they are part of a Union.
If only there was an option to expand them otherwise as well 🙂

[jakebailey]

They expand because Unions are normalized and type alias names get lost.

TypeScript recently changed this behavior themselves (as they used to do what we do), but we had been pondering adopting their method to preserve type names as much as possible (which is probably the opposite direction you were hoping for).

[vishwa-raj]

@jakebailey Think about it this way:

A type alias allows us to define a large and complex type annotation once and use it multiple times throughout our code, helping to keep it concise and clear.

Now say I import the function func, in the above screenshot, in a file and try to call it by providing the arguments.
The tooltip, like in the second screenshot, will show me ANIMAL_T instead of the actual values, and to know the actual values I'll have to navigate to the source file and check the definition for ANIMAL_T.
And if I have to navigate to the source file to get that info, what's the point of having the suggestion tooltips in the first place ?

[vishwa-raj]

In PyCharm too we get the expanded view in tooltips.

[macintacos]

To share my experience with this, I find it to be a little abrasive from a "developer experience" point of view to need to go-to-def on a type alias that I created more-so to save me from typing out a complicated type, not to "hide" the type.

Granted, at some point one must realize that you're probably just abusing the type system and should refactor 😅 but occasionally I stop myself from creating an alias simply so that I can still see the type information at a glance (or, at-least easier than doing a go-to-def on the alias itself). I'd really appreciate the ability to just see the whole type when hovering, or perhaps show the alias and the type it expands to side-by-side when I hover on a variable that uses the alias. The current implementation seems to actively want to discourage type aliasing because of the reasons previously stated (and the reasons other folks have mentioned in this thread).

All of this to just say - I'd really like for this to be implemented 🙂