config source of truth?

[llllvvuu]

Some things I observed when I stumbled upon #2665:

1. The config which is passed into WagmiConfig is not used much. Most of the hooks just call @wagmi/core.
2. The reason we can just call @wagmi/core outside of the React tree, and even call with no config variable, is because createConfig (both the React version and the core version) has the side effect of setting a global variable. This global variable is the source of truth. This side-effect is non-obvious since given the name createConfig and it's not documented.

While it's nice that we can do 2., it comes at the cost of the pitfalls of global variables (#2665) and not being the React way. Why not either go all the way and have no Provider, or go all the way and use useConfig() everywhere as the source of truth (the idiomatic React way / developer expectation)?

One way to incrementally adopt useConfig() could be to add an optional wagmiConfig parameter to the @wagmi/core functions so that lines like const config = getConfig() become const config = wagmiConfig ?? getConfig(). Then the hooks can call like:

const config = useConfig()
const watchAccount = useCallback(callback => watchAccountCore(callback, undefined, config), [config])

^this would be mostly backwards-compatible, though technically still breaking, because JavaScript lets you pass in extra junk parameters and some users could be doing that

One could then go further and make a more breaking change like:

• rename @wagmi/core's createConfig to setConfig and document the side effect
• keep wagmi (React)'s createConfig as createConfig but remove the side effect (React users can then no longer call vanilla @wagmi/core without passing in config)

Thoughts? Open to the idea? Open to contributions?

[tmm]

Nice spot! This is something we are working on addressing in v2.