v/vlib/v/tests/array_methods_test.v

33 lines
764 B
V

struct Counter {
mut:
val int
}
// if this is called more than once, the test'll fail
fn (mut c Counter) new_arr(msg string) []int {
if c.val > 0 {
panic(msg)
}
c.val++
return [1, 3, 2]
}
fn test_array_eval_count() {
// `new_arr()` should only be evaluated once, not on every iteration
mut a1 := Counter{}
assert a1.new_arr('map() failed').map(it * 2) == [2, 6, 4]
mut a2 := Counter{}
assert a2.new_arr('filter() failed').filter(it < 3) == [1, 2]
mut a3 := Counter{}
assert a3.new_arr('any() failed').any(it == 2) == true
a3 = Counter{}
assert a3.new_arr('any() failed').any(it < 0) == false
mut a4 := Counter{}
assert a4.new_arr('all() failed').all(it > 0) == true
a4 = Counter{}
assert a4.new_arr('all() failed').all(it == 2) == false
}