Initiate the HTTP connection before writing the body stream

test-programs/src/bin/client_post_with_body.rs

@@ -8,15 +8,20 @@ struct Data {
 }
 
 fn main() {
-    let buffer = [0; 5000];
+    // Make sure the final body is larger than 1024*1024, but we cannot allocate
+    // so much memory directly in the wasm program, so we use the `repeat`
+    // method to increase the body size.
+    const LEN: usize = 1024;
+    const REPEAT: usize = 1025;
+    let buffer = [0; LEN];
     let resp = Client::new()
         .post("https://httpbin.org/post")
-        .body(buffer)
+        .body(buffer.repeat(REPEAT))
         .connect_timeout(Duration::from_secs(5))
         .send()
         .unwrap();
     assert_eq!(resp.status_code(), 200);
 
     let data = resp.json::<Data>().unwrap();
-    assert_eq!(data.data.len(), 5000);
+    assert_eq!(data.data.len(), LEN * REPEAT);
 }

waki/src/request.rs

@@ -232,19 +232,20 @@ impl Request {
                 .map_err(|()| anyhow!("failed to set path_with_query"))?;
         }
 
+        let outgoing_body = req
+            .body()
+            .map_err(|_| anyhow!("outgoing request write failed"))?;
+
         let options = RequestOptions::new();
         options
             .set_connect_timeout(self.connect_timeout)
             .map_err(|()| anyhow!("failed to set connect_timeout"))?;
+        let future_response = outgoing_handler::handle(req, Some(options))?;
 
-        let outgoing_body = req
-            .body()
-            .map_err(|_| anyhow!("outgoing request write failed"))?;
         let body = self.body.bytes()?;
         write_to_outgoing_body(&outgoing_body, body.as_slice())?;
         OutgoingBody::finish(outgoing_body, None)?;
 
-        let future_response = outgoing_handler::handle(req, Some(options))?;
         let incoming_response = match future_response.get() {
             Some(result) => result.map_err(|()| anyhow!("response already taken"))?,
             None => {