Example
This type of testing is popular technique for testing with predefined input and output values.
Create a file called main.go with content:
package main
import (
"fmt"
)
func main() {
fmt.Println(Sum(4, 5))
}
func Sum(a, b int) int {
return a + b
}
After you run it with, you will see that the output is 9. Although the Sum function looks pretty simple, it is a good idea to test your code. In order to do this, we create another file named main_test.go in the same folder as main.go, containing the following code:
package main
import (
"testing"
)
// Test methods start with Test
func TestSum(t *testing.T) {
// Note that the data variable is of type array of anonymous struct,
// which is very handy for writing table-driven unit tests.
data := []struct {
a, b, res int
}{
{1, 2, 3},
{0, 0, 0},
{1, -1, 0},
{2, 3, 5},
{1000, 234, 1234},
}
for _, d := range data {
if got := Sum(d.a, d.b); got != d.res {
t.Errorf("Sum(%d, %d) == %d, want %d", d.a, d.b, got, d.res)
}
}
}
As you can see, a slice of anonymous structs is created, each with a set of inputs and the expected result. This allows a large number of test cases to be created all together in one place, then executed in a loop, reducing code repetition and improving clarity.
