stream_assert

Macros to simplify testing of Stream based APIs.

Provides the following assertion macros:

```rust // Assert that the next value is ready and equal to the given expression. assertnexteq!(stream, expression);

// Assert that the next value is ready and matches the given pattern. assertnextmatches!(stream, Enum::Variant { field: 1, .. });

// Assert that the stream is not ready (poll_next returns Pending). assert_pending!(stream);

// Assert that the stream is closed (poll_next returns Ready(None)). assert_closed!(stream); ```