Check error methods on types

[mmwtsn]

Is there a way to check if the Err method on a type is called?

For example, the standard library's bufio#Scanner type:

package main

import (
        "bufio"
        "fmt"
        "os"
)

func main() {
        scanner := bufio.NewScanner(os.Stdin)
        for scanner.Scan() {
                fmt.Println(scanner.Text())
        }
        if err := scanner.Err(); err != nil {
             fmt.Fprintln(os.Stderr, "reading standard input:", err)
        }
}

Removing the if err := scanner.Err() block is not caught by errcheck.

[kisielk]

No there is not, and I think it's beyond the scope of this tool. I'm not sure it would even be possible to implement this given that Err could be called at any later point in the program, or dynamically via an interface, etc.