chore: add missing tests for var-declarations, fix any/interface{} type issue

[denisvmedia]

Fixes #1152

[chavacava]

IMO, in cases of the form var <id> any = <value> where value is not nil the rule must warn with should omit type any from declaration of var <id>; it will be inferred from the right-hand side because var <id> = <value> is equivalent

[denisvmedia]

To be clear, are you saying that var <id> any = <non_nil_value> is the same as var <id> = <value>?

[chavacava]

Yes

https://go.dev/play/p/TORLftc7jlR with any
https://go.dev/play/p/dYvM0OlUstA without any

both outputs are the same

a value's is 100 and it is of type int

[chavacava]

if an initial value is provided then declaring the variable of being type any has no utility

[denisvmedia]

Still, I think there is a difference. With any it is a dynamic type and it can be changed to any value later. Consider this:

package main

func main() {
	var a1 = 1
	// a1 = "string" // fail to compile
	var a2 any = 1
	a2 = "string" // this will compile
	_ = a1
	_ = a2
}

[denisvmedia]

declaring the variable of being type any has no utility

I believe there can be a reason to declare an any type variable in case if you plan to have an arbitrary value for it later.

[chavacava]

Ooops; you are right... I did not think in these kind of (ugly) cases

[denisvmedia]

@chavacava I updated the tests. Are you fine with the current state?

[ccoVeille]

I don't understand the last commit that provide a strange import order

[denisvmedia]

It reverts what I committed by mistake.