Fix using the entire available buffer

src/response/chunked.rs

@@ -156,7 +156,7 @@ where
         };
 
         let mut len = 0;
-        while len < reader.raw_body.buffer.buffer.len() {
+        while !reader.raw_body.buffer.buffer.is_empty() {
             // Read some
             let read = reader.fill_buf().await?.len();
             len += read;

src/response/mod.rs

@@ -604,6 +604,21 @@ mod tests {
         assert!(conn.is_exhausted());
     }
 
+    #[tokio::test]
+    async fn can_read_to_end_into_a_small_buffer() {
+        let mut conn = FakeSingleReadConnection::new(
+            b"HTTP/1.1 200 OK\r\nTransfer-Encoding: chunked\r\n\r\n5\r\nHELLO\r\n6\r\n WORLD\r\n1\r\n \r\n5\r\nHELLO\r\n6\r\n WORLD\r\n1\r\n \r\n5\r\nHELLO\r\n6\r\n WORLD\r\n0\r\n\r\n",
+        );
+        conn.read_length = 10;
+        let mut header_buf = [0; 50]; // buffer is long enough to hold the complete response
+        let response = Response::read(&mut conn, Method::GET, &mut header_buf).await.unwrap();
+
+        let body = response.body().read_to_end().await.unwrap();
+
+        assert_eq!(b"HELLO WORLD HELLO WORLD HELLO WORLD", body);
+        assert!(conn.is_exhausted());
+    }
+
     #[tokio::test]
     async fn can_read_to_end_of_connection_with_same_buffer() {
         let mut conn = FakeSingleReadConnection::new(b"HTTP/1.1 200 OK\r\n\r\nHELLO WORLD");