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staticcheck feature request: add check when user try to modify global variable on other package #1152
Description
user should not be able to modify global variables inside another package because it can result in data race and other undesired behavior
for example, the following code should generate a check error
package main
import (
"errors"
"net/http"
)
func main() {
http.DefaultServeMux = http.NewServeMux() // <-- here
http.ErrAbortHandler = errors.New("override") // <-- or here
}in general, a global identifier should be const, but it is not possible in golang because we need to initialize it with a non-zero value
thanks
Reacted by Ainar Garipov
Activity
ainar-g commentedon Dec 28, 2021
I would love to have this check, but it probably will only be included as an
aggresivecheck, not as a standard one. Some people choose to modify “foreign globals” in tests or, in case withnet/http, to change the settings of the default clients.dominikh commentedon Jan 7, 2022
This can at best be an
aggressivecheck, for the reasons Ainar already mentioned. Expanding on that, it's not correct to say that no foreign globals should ever be assigned to, nor that it cannot be done correctly.I am, however, not sure how useful this check would be in the
aggressivecategory. It seems unlikely to me that someone would assign to a global by accident.soypat commentedon Jul 2, 2023
Maybe implementing a subset of this for assigning to an
errortype would be less agressive? And even less agressive would be implementing this only for standard library errors.