Autocomplete/IntelliSense works only under very specific circumstances

[lukebarton]

Originally posted in flow-for-vscode but I imagine the issue actually lies with the language server since the behaviour is identical in Atom, so raising here retrospectively.

Maybe I'm doing something completely wrong but I've been trying to get flow working nicely in VSCode for several hours. I've concluded that IntelliSense with flow has some real issues and recorded this gif showing two ways I believe it's broken:

1. Chaining causes IntelliSense to stop working.
2. Trying to use it preceding an anonymous function without a semicolon somewhere between causes IntelliSense to stop working.

These issues may be related. Needless to say, it's making Flow pretty difficult to work with.

flow 0.69.0
flow-for-vscode 0.8.0

[namuol]

@lukebarton Are you using the flow.useLSP: true in your VSCode config?

https://github.com/flowtype/flow-for-vscode/blob/438cad0395be64cb4cf337648d595742354fd5b7/package.json#L55-L58

[lukebarton]

Yes, but the option makes no difference. I think I jumped the gun a bit - I didn't realise that the language server wasn't the default implementation yet. I think the issue lies somewhere more core to flow than just the language server or the vscode implementation. It seems what flow itself is returning isn't as expected.

[namuol]

@lukebarton Hmm -- technically flow-language-server does implement autocompletion, as far as I can tell:

https://github.com/flowtype/flow-language-server/blob/daa83c3bc5d6323f0e1ce17bfd38c04ad43f52b9/packages/flow-language-server/src/Completion.js#L43-L46

Try disabling @builtin typescript in VSCode and enabling useLSP, like so.

After doing that, give it another try -- sometimes the issue is just that Flow itself doesn't know enough about the type 🤞 Good luck!

[lukebarton]

TypeScript builtin is disabled. I tried both LSP on and off. The behaviour is the same in Atom as with VS Code.

[namuol]

@lukebarton If you're using LSP and autocomplete isn't working, my guess would be that Flow actually doesn't know enough about the type of the symbol you're interacting with to provide you with completion features -- try hovering over the symbol to see what Flow reports its type as.

Otherwise, it may indeed be a bug with the LSP implementation -- without more detailed information it'll be hard for us to know; @wbinnssmith any recommendations on how to provide debugging information to bug reports like this one?

[lukebarton]

1. It works, just in limited situations.
2. I posted a gif in the original post showing what happens.
3. You can see all of the code.
4. It was the first project I started in VS Code. (Clean install) I disabled the TypeScript plugin.
5. I also tried it in Atom. Exactly the same behaviour.

If that's just how flow works then that's okay with me

[namuol]

I posted a gif in the original post showing what happens.

Yeah I just wasn't sure if that gif was still the exact behavior, as you mentioned you may have posted that while not using useLSP:

I think I jumped the gun a bit - I didn't realise that the language server wasn't the default implementation yet.

Didn't mean to belittle your experience! The behavior in the gif is really confusing/frustrating, for sure. I'm just trying to clarify so we can track down the issue with precision -- Thanks! 🙇

[lukebarton]

So I tried with LSP on and off, no difference. On/Off/VS Code/Atom all the same. It's probably a flow core thing.

Sorry for replying with a numbered list. It's been a long day and I didn't want to write the fluffy nice stuff you usually have to - there's no beef/ill feeling 👍

[namuol]

Sorry for replying with a numbered list.

No worries 😂 Thanks for replying 👍

So I tried with LSP on and off, no difference. On/Off/VS Code/Atom all the same.

It's probably a flow core thing.

Maybe, but the behavior in that gif still looks really odd. When you find the time, would you mind recording the same sequences of behaviors with LSP on in VSCode? It may be some combination of both Flow's core "type of symbol" reporting that can be addressed in the LSP integration 🤔