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use futures::future;
use futures::stream;
use futures_test::future::FutureTestExt;
use futures_test::{assert_stream_done, assert_stream_next, assert_stream_pending};
#[test]
fn unfold1() {
let mut stream = stream::unfold(0, |state| {
if state <= 2 {
future::ready(Some((state * 2, state + 1))).pending_once()
} else {
future::ready(None).pending_once()
}
});
// Creates the future with the closure
// Not ready (delayed future)
assert_stream_pending!(stream);
// Future is ready, yields the item
assert_stream_next!(stream, 0);
// Repeat
assert_stream_pending!(stream);
assert_stream_next!(stream, 2);
assert_stream_pending!(stream);
assert_stream_next!(stream, 4);
// No more items
assert_stream_pending!(stream);
assert_stream_done!(stream);
}