Ability to toggle assertion linter for interfaces

[dopey]

errors can have interfaces - e.g., StackTracer, Logger, Renderable, etc.

In order to check if an error implements an interface (to check if, for example, we can call e.StackTrace()) we do a type assertion. There isn't an easy way to change this to use errors.As because we can't marshal the error into an interface.

I would be nice to be able to turn off errors about type assertion against interfaces.

[polyfloyd]

Hi,

Actually, you can use errors.As with interfaces. Consider the following example:

package main

import (
    "errors"
    "fmt"
)

func main() {
    err := geterr()

    var thing interface {
        Foo()
    }
    if errors.As(err, &thing) {
        thing.Foo()
    }
    fmt.Println(err)
}

func geterr() error {
    return fmt.Errorf("geterr: %w", Fooer{})
}

type Fooer struct{}

func (Fooer) Error() string {
    return "fooer"
}

func (Fooer) Foo() {
    fmt.Println("foo")
}

This will print:

foo
geterr: fooer

[dopey]

This is great! Thanks for the response.