Function TestDynamicDispatch

cel/cel_test.go:2992–3053

(t *testing.T)

}

func TestDynamicDispatch(t *testing.T) {
	env := testEnv(t,
		HomogeneousAggregateLiterals(),
		Function("first",
			MemberOverload("first_list_int", []*Type{ListType(IntType)}, IntType,
				UnaryBinding(func(list ref.Val) ref.Val {
					l := list.(traits.Lister)
					if l.Size() == types.IntZero {
						return types.IntZero
					}
					return l.Get(types.IntZero)
				}),
			),
			MemberOverload("first_list_double", []*Type{ListType(DoubleType)}, DoubleType,
				UnaryBinding(func(list ref.Val) ref.Val {
					l := list.(traits.Lister)
					if l.Size() == types.IntZero {
						return types.Double(0.0)
					}
					return l.Get(types.IntZero)
				}),
			),
			MemberOverload("first_list_string", []*Type{ListType(StringType)}, StringType,
				UnaryBinding(func(list ref.Val) ref.Val {
					l := list.(traits.Lister)
					if l.Size() == types.IntZero {
						return types.String("")
					}
					return l.Get(types.IntZero)
				}),
			),
			MemberOverload("first_list_list_string", []*Type{ListType(ListType(StringType))}, ListType(StringType),
				UnaryBinding(func(list ref.Val) ref.Val {
					l := list.(traits.Lister)
					if l.Size() == types.IntZero {
						return types.DefaultTypeAdapter.NativeToValue([]string{})
					}
					return l.Get(types.IntZero)
				}),
			),
		),
	)
	out, err := interpret(t, env, `
		dyn([]).first() == 0
		&& [1, 2].first() == 1
		&& [1.0, 2.0].first() == 1.0
		&& ["hello", "world"].first() == "hello"
		&& [["hello"], ["world", "!"]].first().first() == "hello"
		&& [[], ["empty"]].first().first() == ""
		&& dyn([1, 2]).first() == 1
		&& dyn([1.0, 2.0]).first() == 1.0
		&& dyn(["hello", "world"]).first() == "hello"
		&& dyn([["hello"], ["world", "!"]]).first().first() == "hello"
	`, map[string]any{},
	)
	if err != nil {
		t.Fatalf("prg.Eval() failed: %v", err)
	}