addInt_test.go

You might have also noticed in TestSimpleVariadicToSlice that we duplicated a lot of logic, while the only varying factor was the input and expected values. One style of testing, known as Table-driven development, defines a table of all the required data to run a test, iterates over the "rows" of the table and runs tests against them.

Let's look at the tests we will be testing against no arguments and variadic arguments:

// addInt_test.go 
 
package main 
 
import ( 
    "testing" 
) 
 
func TestAddInt(t *testing.T) { 
    testCases := []struct { 
        Name     string 
        Values   []int 
        Expected int 
    }{ 
        {"addInt() -> 0", []int{}, 0}, 
        {"addInt([]int{10, 20, 100}) -> 130", []int{10, 20, 100}, 130}, 
    } 
 
    for _, tc := range testCases { 
        t.Run(tc.Name, func(t *testing.T) { 
            sum := addInt(tc.Values...) 
            if sum != tc.Expected { 
                t.Errorf("%d != %d", sum, tc.Expected) 
            } else { 
                t.Logf("%d == %d", sum, tc.Expected) 
            } 
        }) 
    } 
}