add async multipart request handling

tests/async.rs

@@ -1,12 +1,14 @@
 extern crate futures;
 extern crate libflate;
 extern crate reqwest;
+extern crate hyper;
 extern crate tokio;
 
 #[macro_use]
 mod support;
 
 use reqwest::async::Client;
+use reqwest::async::multipart::{Form, Part};
 use futures::{Future, Stream};
 use std::io::Write;
 use std::time::Duration;
@@ -21,6 +23,78 @@ fn async_test_gzip_single_byte_chunks() {
     test_gzip(10, 1);
 }
 
+#[test]
+fn async_test_multipart() {
+    let _ = env_logger::try_init();
+
+    let stream = futures::stream::once::<_, hyper::Error>(Ok(hyper::Chunk::from("part1 part2".to_owned())));
+    let part = Part::stream(stream);
+
+    let form = Form::new()
+        .text("foo", "bar")
+        .part("part_stream", part);
+
+    let expected_body = format!("\
+        24\r\n\
+        --{0}\r\n\r\n\
+        2E\r\n\
+        Content-Disposition: form-data; name=\"foo\"\r\n\r\n\r\n\
+        3\r\n\
+        bar\r\n\
+        2\r\n\
+        \r\n\r\n\
+        24\r\n\
+        --{0}\r\n\r\n\
+        36\r\n\
+        Content-Disposition: form-data; name=\"part_stream\"\r\n\r\n\r\n\
+        B\r\n\
+        part1 part2\r\n\
+        2\r\n\
+        \r\n\r\n\
+        26\r\n\
+        --{0}--\r\n\r\n\
+        0\r\n\r\n\
+    ", form.boundary());
+
+    let server = server! {
+        request: format!("\
+            POST /multipart/1 HTTP/1.1\r\n\
+            user-agent: $USERAGENT\r\n\
+            accept: */*\r\n\
+            content-type: multipart/form-data; boundary={}\r\n\
+            accept-encoding: gzip\r\n\
+            host: $HOST\r\n\
+            transfer-encoding: chunked\r\n\
+            \r\n\
+            {}\
+            ", form.boundary(), expected_body),
+        response: b"\
+            HTTP/1.1 200 OK\r\n\
+            Server: multipart\r\n\
+            Content-Length: 0\r\n\
+            \r\n\
+            "
+    };
+
+    let url = format!("http://{}/multipart/1", server.addr());
+
+    let mut rt = tokio::runtime::current_thread::Runtime::new().expect("new rt");
+
+    let client = Client::new();
+
+    let res_future = client.post(&url)
+        .multipart(form)
+        .send()
+        .and_then(|res| {
+            assert_eq!(res.url().as_str(), &url);
+            assert_eq!(res.status(), reqwest::StatusCode::OK);
+
+            Ok(())
+        });
+
+    rt.block_on(res_future).unwrap();
+}
+
 fn test_gzip(response_size: usize, chunk_size: usize) {
     let content: String = (0..response_size).into_iter().map(|i| format!("test {}", i)).collect();
     let mut encoder = ::libflate::gzip::Encoder::new(Vec::new()).unwrap();