Why null-ls returns hoverProvider = true

[ray-x]

Do I need some setup (e.g. add gitsigns, eslint) to make hover work for null-ls? or, should it return false.

ATM if I send hover request, it failed.
Also saw this warnings, not sure if it is related
[WARN Thu 09 Jun 2022 16:32:42] .../pack/packer/opt/null-ls.nvim/lua/null-ls/generators.lua:78: failed to run generator: ...t/null-ls.nvim/lua/null-ls/helpers/generator_factory.lua:64: failed to decode json: Expected value but found invalid token at character 1

I tried to submit an issue, but the template prevents me to do that even if all (*) fields are checked/filled.

[jose-elias-alvarez]

Not sure what's going on with the issue template - I just tried to open a test issue and it worked for me, so I'd recommend trying again, since I don't have enough information to debug your warning.

To answer your first question: since Neovim doesn't yet support dynamic capability registration, null-ls declares all of its capabilities on init, then overrides supports_method to determine whether it can respond to specific requests. In this case, registering a hover provider should be enough - we have one built-in source that's mostly a proof of concept, but you could also make your own.