package operator

import "testing"

func TestAdd(t *testing.T) {
    got := Add(2, 3)
    if got != 5 {
        t.Fatalf("Add(2,3) = %d; want 5", got)
    }
}

func TestSub(t *testing.T) {
    got := Sub(5, 3)
    if got != 2 {
        t.Fatalf("Sub(5,3) = %d; want 2", got)
    }
}

func TestMul(t *testing.T) {
    got := Mul(4, 3)
    if got != 12 {
        t.Fatalf("Mul(4,3) = %d; want 12", got)
    }
}

func TestDiv(t *testing.T) {
    got, err := Div(7, 2)
    if err != nil {
        t.Fatalf("unexpected error: %v", err)
    }
    if got != 3.5 {
        t.Fatalf("Div(7,2) = %v; want 3.5", got)
    }
}

func TestDivByZero(t *testing.T) {
    _, err := Div(1, 0)
    if err == nil {
        t.Fatalf("expected error when dividing by zero")
    }
}