tokio: add AsyncBufReadExt::lines

1 files changed, 53 insertions, 0 deletions

diff --git a/tokio/tests/io_lines.rs b/tokio/tests/io_lines.rs
new file mode 100644
index 00000000..02ce6149
--- /dev/null
+++ b/tokio/tests/io_lines.rs
@@ -0,0 +1,53 @@
+#![deny(warnings, rust_2018_idioms)]
+#![feature(async_await)]
+
+use futures_util::StreamExt;
+use tokio::io::{AsyncBufRead, AsyncBufReadExt, AsyncRead};
+use tokio_test::assert_ok;
+
+use std::io;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+#[tokio::test]
+async fn lines() {
+    struct Rd {
+        val: &'static [u8],
+    }
+
+    impl AsyncRead for Rd {
+        fn poll_read(
+            self: Pin<&mut Self>,
+            _: &mut Context<'_>,
+            _: &mut [u8],
+        ) -> Poll<io::Result<usize>> {
+            unimplemented!()
+        }
+    }
+
+    impl AsyncBufRead for Rd {
+        fn poll_fill_buf<'a>(
+            self: Pin<&'a mut Self>,
+            _: &mut Context<'_>,
+        ) -> Poll<io::Result<&'a [u8]>> {
+            Poll::Ready(Ok(self.val))
+        }
+
+        fn consume(mut self: Pin<&mut Self>, amt: usize) {
+            self.val = &self.val[amt..];
+        }
+    }
+
+    let rd = Rd {
+        val: b"hello\r\nworld\n\n",
+    };
+    let mut st = rd.lines();
+
+    let b = assert_ok!(st.next().await.unwrap());
+    assert_eq!(b, "hello");
+    let b = assert_ok!(st.next().await.unwrap());
+    assert_eq!(b, "world");
+    let b = assert_ok!(st.next().await.unwrap());
+    assert_eq!(b, "");
+    assert!(st.next().await.is_none());
+}