We're moving Fuego Context from "generic type constrained by an interface" to "interface". We're doing this for two reasons.

First, to unify Fuego framework around one unique interface that every framework will implement, with netHttpContext, ginContext, echoContext. It also allows, like Echo, to provide custom Contexts for testing, and is very flexible.

Second, because the hard thing with Generic Context type constrained by an interface is initialization. We have this ugly initialization function in serve.go called initContext.

With this PR, this unique interface is ContextWithBody[B], ContextNoBody being just an alias to ContextWithBody[any]. I wish there was a nil type, because I want to describe emptiness (nil), not "everything" (any), but Go does not allow that (that I know). When Go1.24 will go out, we will have Context[B, P] as main interface, and we'll keep ContextWithBody[B] as an alias to Context[B, any].

Release notes draft

We're changing Fuego's signature from "generic type constrained by interface" to an interface

Simply replace *fuego.ContextNoBody by fuego.ContextNoBody and *fuego.ContextWithBody by fuego.ContextWithBody

Automatically make all required changes:

For macOS (BSD sed):

find . -type f -exec sed -i '' 's/\*fuego\.ContextNoBody/fuego\.ContextNoBody/g; s/\*fuego\.ContextWithBody/fuego\.ContextWithBody/g' {} +

For Linux (GNU sed):

find . -type f -exec sed -i 's/\*fuego\.ContextNoBody/fuego\.ContextNoBody/g; s/\*fuego\.ContextWithBody/fuego\.ContextWithBody/g' {} +