buf: impl size_hint for str types + reorg tests (#1012)

tokio-buf/tests/string.rs

@@ -0,0 +1,39 @@
+extern crate bytes;
+extern crate futures;
+extern crate tokio_buf;
+
+use bytes::Buf;
+use futures::Async::*;
+use std::fmt;
+use tokio_buf::BufStream;
+
+#[macro_use]
+mod support;
+
+fn test_hello_world<B>(mut bs: B)
+where
+    B: BufStream + fmt::Debug,
+    B::Item: fmt::Debug,
+    B::Error: fmt::Debug,
+{
+    let hint = bs.size_hint();
+    assert_eq!(hint.lower(), 11);
+    assert_eq!(hint.upper(), Some(11));
+
+    assert_buf_eq!(bs.poll_buf(), "hello world");
+
+    let hint = bs.size_hint();
+    assert_eq!(hint.lower(), 0);
+    assert_eq!(hint.upper(), Some(0));
+    assert_none!(bs.poll_buf());
+}
+
+#[test]
+fn string() {
+    test_hello_world("hello world".to_string());
+}
+
+#[test]
+fn str() {
+    test_hello_world("hello world");
+}