add async reader test

Cargo.toml

@@ -37,6 +37,7 @@ quickcheck = { version = "0.7", default-features = false }
 tokio-io = "0.1.11"
 tokio-tcp = "0.1.3"
 tokio-threadpool = "0.1.10"
+futures = "0.1"
 
 [features]
 default = ["miniz-sys"]

tests/async-reader.rs

@@ -0,0 +1,78 @@
+extern crate flate2;
+extern crate tokio_io;
+extern crate futures;
+
+use flate2::read::GzDecoder;
+use std::cmp;
+use std::fs::File;
+use std::io::{self, Read};
+use tokio_io::AsyncRead;
+use tokio_io::io::read_to_end;
+use futures::prelude::*;
+use futures::task;
+
+
+struct BadReader<T> {
+    reader: T,
+    x: bool
+}
+
+impl<T> BadReader<T> {
+    fn new(reader: T) -> BadReader<T> {
+        BadReader { reader, x: true }
+    }
+}
+
+impl<T: Read> Read for BadReader<T> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        if self.x {
+            self.x = false;
+            let len = cmp::min(buf.len(), 1);
+            self.reader.read(&mut buf[..len])
+        } else {
+            self.x = true;
+            Err(io::ErrorKind::WouldBlock.into())
+        }
+    }
+}
+
+struct AssertAsync<T>(T);
+
+impl<T: Read> Read for AssertAsync<T> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.0.read(buf)
+    }
+}
+
+impl<T: Read> AsyncRead for AssertAsync<T> {}
+
+struct AlwaysNotify<T>(T);
+
+impl<T: Future> Future for AlwaysNotify<T> {
+    type Item = T::Item;
+    type Error = T::Error;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        let ret = self.0.poll();
+        if let Ok(Async::NotReady) = &ret {
+            task::current().notify();
+        }
+        ret
+    }
+}
+
+#[test]
+fn test_gz_asyncread() {
+    let f = File::open("tests/good-file.gz").unwrap();
+
+    let fut = read_to_end(AssertAsync(GzDecoder::new(BadReader::new(f))), Vec::new());
+    let (_, content) = AlwaysNotify(fut).wait().unwrap();
+
+    let mut expected = Vec::new();
+    File::open("tests/good-file.txt")
+        .unwrap()
+        .read_to_end(&mut expected)
+        .unwrap();
+
+    assert!(content == expected);
+}