Check that Interface value is equal to nil
If interface contains nil, it can be not equal nil, e.g.

func main() { 
  var x interface{}
  var y *int = nil
  x = y

  if x != nil {
    fmt.Println("x != nil") // <-- actual
  } else {
    fmt.Println("x == nil")
  }
  fmt.Println(x) } // x != nil // <nil>

prints

x != nil
<nil>

To correctly check if interface is equal to nil, you can write function, similar to

func IsNil(x interface{}) bool {
  if x == nil {
    return true
  }

  return reflect.ValueOf(x).IsNil()
}

This function will work as expected.
#tip #example
@golang_tips

new vs make
Both make() and new() are used for memory allocation. But make() returns initialized type value, while new() returns nil-pointer to type.

a := new(chan int) // a has *chan int type
b := make(chan int) // b has chan int type

#tip #example
@golang_tips