package underscore_test import ( "testing" "github.com/stretchr/testify/assert" u "github.com/rjNemo/underscore" ) var ( zero = u.Tuple[int, string]{Left: 0, Right: "Zero"} one = u.Tuple[int, string]{Left: 1, Right: "One"} two = u.Tuple[int, string]{Left: 2, Right: "Two"} three = u.Tuple[int, string]{Left: 3, Right: "Three"} ) func Test_Join_Can_Join_Two_Slices_Together(t *testing.T) { left := []u.Tuple[int, string]{zero, one, two, three} right := []u.Tuple[int, string]{one, three, two, three, two, three} selector := func(x u.Tuple[int, string]) int { return x.Left } joined := u.Join(left, right, selector, selector) want := []u.Tuple[u.Tuple[int, string], []u.Tuple[int, string]]{ {Left: zero, Right: nil}, {Left: one, Right: []u.Tuple[int, string]{one}}, {Left: two, Right: []u.Tuple[int, string]{two, two}}, {Left: three, Right: []u.Tuple[int, string]{three, three, three}}, } assert.Equal(t, want, joined) } func Test_Join_Can_Join_and_Project_Two_Slices_Together(t *testing.T) { left := []u.Tuple[int, string]{zero, one, two, three} right := []u.Tuple[int, string]{one, three, two, three, two, three} selector := func(x u.Tuple[int, string]) int { return x.Left } project := func(x u.Tuple[u.Tuple[int, string], []u.Tuple[int, string]]) int { return len(x.Right) // projecting to a could of how many } joined := u.JoinProject(left, right, selector, selector, project) want := []int{0, 1, 2, 3} assert.Equal(t, want, joined) }