Add an AppendBuf

test/test.rs

@@ -4,6 +4,7 @@ extern crate bytes;
 extern crate rand;
 extern crate byteorder;
 
+mod test_append;
 mod test_buf;
 mod test_buf_fill;
 mod test_buf_take;

test/test_append.rs

@@ -0,0 +1,30 @@
+use bytes::{ByteStr, Buf, MutBuf};
+use bytes::buf::AppendBuf;
+
+#[test]
+pub fn test_initial_buf_empty() {
+    // Run in a loop a bunch in hope that if there is a memory issue, it will
+    // be exposed
+    for _ in 0..1000 {
+        let mut buf = AppendBuf::with_capacity(100);
+        let mut dst: Vec<u8> = vec![];
+
+        assert_eq!(buf.remaining(), 128);
+
+        buf.write_slice(b"hello world");
+        assert_eq!(buf.remaining(), 117);
+        assert_eq!(buf.bytes(), b"hello world");
+
+        let view1 = buf.slice(0, 11);
+        view1.buf().copy_to(&mut dst).unwrap();
+
+        assert_eq!(dst, b"hello world");
+        assert_eq!(view1, buf.slice(0, 11));
+
+        drop(buf);
+        let mut buf = AppendBuf::with_capacity(100);
+        buf.write_slice(b"zomg no no no no");
+
+        assert_eq!(dst, b"hello world");
+    }
+}