Sometimes you need to test the behavior of a process, not just a function.
func Crasher() {
fmt.Println("Going down in flames!")
os.Exit(1)
}To test this code, we invoke the test binary itself as a subprocess:
func TestCrasher(t *testing.T) {
if os.Getenv("BE_CRASHER") == "1" {
Crasher()
return
}
cmd := exec.Command(os.Args[0], "-test.run=TestCrasher")
cmd.Env = append(os.Environ(), "BE_CRASHER=1")
err := cmd.Run()
if e, ok := err.(*exec.ExitError); ok && !e.Success() {
return
}
t.Fatalf("process ran with err %v, want exit status 1", err)
}核心技巧在于os.args[0]可以获取到真实的可执行 test 程序,从而改变环境变量.
原文：https://www.cnblogs.com/baizx/p/9058372.html