1 files changed, 107 insertions, 0 deletions
diff --git a/third_party/rust/tokio/tests/io_read_line.rs b/third_party/rust/tokio/tests/io_read_line.rs
new file mode 100644
index 0000000000..15841c9b49
--- /dev/null
+++ b/third_party/rust/tokio/tests/io_read_line.rs
@@ -0,0 +1,107 @@
+#![warn(rust_2018_idioms)]
+#![cfg(feature = "full")]
+
+use std::io::ErrorKind;
+use tokio::io::{AsyncBufReadExt, BufReader, Error};
+use tokio_test::{assert_ok, io::Builder};
+
+use std::io::Cursor;
+
+#[tokio::test]
+async fn read_line() {
+    let mut buf = String::new();
+    let mut rd = Cursor::new(b"hello\nworld\n\n");
+
+    let n = assert_ok!(rd.read_line(&mut buf).await);
+    assert_eq!(n, 6);
+    assert_eq!(buf, "hello\n");
+    buf.clear();
+    let n = assert_ok!(rd.read_line(&mut buf).await);
+    assert_eq!(n, 6);
+    assert_eq!(buf, "world\n");
+    buf.clear();
+    let n = assert_ok!(rd.read_line(&mut buf).await);
+    assert_eq!(n, 1);
+    assert_eq!(buf, "\n");
+    buf.clear();
+    let n = assert_ok!(rd.read_line(&mut buf).await);
+    assert_eq!(n, 0);
+    assert_eq!(buf, "");
+}
+
+#[tokio::test]
+async fn read_line_not_all_ready() {
+    let mock = Builder::new()
+        .read(b"Hello Wor")
+        .read(b"ld\nFizzBuz")
+        .read(b"z\n1\n2")
+        .build();
+
+    let mut read = BufReader::new(mock);
+
+    let mut line = "We say ".to_string();
+    let bytes = read.read_line(&mut line).await.unwrap();
+    assert_eq!(bytes, "Hello World\n".len());
+    assert_eq!(line.as_str(), "We say Hello World\n");
+
+    line = "I solve ".to_string();
+    let bytes = read.read_line(&mut line).await.unwrap();
+    assert_eq!(bytes, "FizzBuzz\n".len());
+    assert_eq!(line.as_str(), "I solve FizzBuzz\n");
+
+    line.clear();
+    let bytes = read.read_line(&mut line).await.unwrap();
+    assert_eq!(bytes, 2);
+    assert_eq!(line.as_str(), "1\n");
+
+    line.clear();
+    let bytes = read.read_line(&mut line).await.unwrap();
+    assert_eq!(bytes, 1);
+    assert_eq!(line.as_str(), "2");
+}
+
+#[tokio::test]
+async fn read_line_invalid_utf8() {
+    let mock = Builder::new().read(b"Hello Wor\xffld.\n").build();
+
+    let mut read = BufReader::new(mock);
+
+    let mut line = "Foo".to_string();
+    let err = read.read_line(&mut line).await.expect_err("Should fail");
+    assert_eq!(err.kind(), ErrorKind::InvalidData);
+    assert_eq!(err.to_string(), "stream did not contain valid UTF-8");
+    assert_eq!(line.as_str(), "Foo");
+}
+
+#[tokio::test]
+async fn read_line_fail() {
+    let mock = Builder::new()
+        .read(b"Hello Wor")
+        .read_error(Error::new(ErrorKind::Other, "The world has no end"))
+        .build();
+
+    let mut read = BufReader::new(mock);
+
+    let mut line = "Foo".to_string();
+    let err = read.read_line(&mut line).await.expect_err("Should fail");
+    assert_eq!(err.kind(), ErrorKind::Other);
+    assert_eq!(err.to_string(), "The world has no end");
+    assert_eq!(line.as_str(), "FooHello Wor");
+}
+
+#[tokio::test]
+async fn read_line_fail_and_utf8_fail() {
+    let mock = Builder::new()
+        .read(b"Hello Wor")
+        .read(b"\xff\xff\xff")
+        .read_error(Error::new(ErrorKind::Other, "The world has no end"))
+        .build();
+
+    let mut read = BufReader::new(mock);
+
+    let mut line = "Foo".to_string();
+    let err = read.read_line(&mut line).await.expect_err("Should fail");
+    assert_eq!(err.kind(), ErrorKind::Other);
+    assert_eq!(err.to_string(), "The world has no end");
+    assert_eq!(line.as_str(), "Foo");
+}