package validate

import "testing"

func TestLuhn(t *testing.T) {
	tests := []struct {
		name string
		pan  string
		want bool
	}{
		{
			"Mastercard",
			"5555555555554444",
			true,
		},
		{
			"Visa",
			"4111111111111111",
			true,
		},
		{
			"example from wiki",
			"17893729974",
			true,
		},
		{
			"another example",
			"79927398713",
			true,
		},
		{
			"worong check digit",
			"17893729975",
			false,
		},
		{
			"off by one error",
			"27893729974",
			false,
		},
		{
			"empty",
			"",
			false,
		},
		{
			"not a digit",
			"27893a29974",
			false,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := Luhn(tt.pan)
			if got != tt.want {
				t.Errorf("Luhn(%s) = %v, want %v", tt.name, got, tt.want)
			}
		})
	}
}