Merge pull request #309 from roc-lang/http-send-result

Modify `Http.send` to that it returns a `Result`

crates/roc_host/src/lib.rs

@@ -540,7 +540,7 @@ pub extern "C" fn roc_fx_send_request(
                 .unwrap_or_else(|_err| roc_http::ResponseToAndFromHost {
                     status: 408,
                     headers: RocList::empty(),
-                    body: "Request Timeout".as_bytes().into(),
+                    body: roc_http::REQUEST_TIMEOUT_BODY.into(),
                 }),
             None => rt.block_on(async_send_request(request)),
         }
@@ -570,7 +570,17 @@ async fn async_send_request(request: hyper::Request<String>) -> roc_http::Respon
 
             let status = status.as_u16();
 
-            let bytes = hyper::body::to_bytes(response.into_body()).await.unwrap();
+            let bytes = match hyper::body::to_bytes(response.into_body()).await {
+                Ok(bytes) => bytes,
+                Err(_) => {
+                    return roc_http::ResponseToAndFromHost {
+                        status: 500,
+                        headers: RocList::empty(),
+                        body: roc_http::REQUEST_BAD_BODY.into(),
+                    };
+                }
+            };
+
             let body: RocList<u8> = RocList::from_iter(bytes);
 
             roc_http::ResponseToAndFromHost {
@@ -584,19 +594,19 @@ async fn async_send_request(request: hyper::Request<String>) -> roc_http::Respon
                 roc_http::ResponseToAndFromHost {
                     status: 408,
                     headers: RocList::empty(),
-                    body: "Request Timeout".as_bytes().into(),
+                    body: roc_http::REQUEST_TIMEOUT_BODY.into(),
                 }
             } else if err.is_connect() || err.is_closed() {
                 roc_http::ResponseToAndFromHost {
                     status: 500,
                     headers: RocList::empty(),
-                    body: "Network Error".as_bytes().into(),
+                    body: roc_http::REQUEST_NETWORK_ERR.into(),
                 }
             } else {
                 roc_http::ResponseToAndFromHost {
                     status: 500,
                     headers: RocList::empty(),
-                    body: err.to_string().as_bytes().into(),
+                    body: format!("OTHER ERROR\n{}", err).as_bytes().into(),
                 }
             }
         }

crates/roc_http/src/lib.rs

@@ -6,6 +6,10 @@ use std::io::{BufRead, BufReader, ErrorKind, Read, Write};
 use std::net::TcpStream;
 use std::sync::OnceLock;
 
+pub const REQUEST_TIMEOUT_BODY: &[u8] = "RequestTimeout".as_bytes();
+pub const REQUEST_NETWORK_ERR: &[u8] = "Network Error".as_bytes();
+pub const REQUEST_BAD_BODY: &[u8] = "Bad Body".as_bytes();
+
 pub fn heap() -> &'static ThreadSafeRefcountedResourceHeap<BufReader<TcpStream>> {
     // TODO: Should this be a BufReader and BufWriter of the tcp stream?
     // like this: https://stackoverflow.com/questions/58467659/how-to-store-tcpstream-with-bufreader-and-bufwriter-in-a-data-structure/58491889#58491889

examples/http-get.roc

@@ -16,7 +16,7 @@ main! = \_args ->
             body: [],
             timeout_ms: TimeoutMilliseconds(5000),
         },
-    )
+    )?
 
     body = (Str.from_utf8(response.body))?
 

platform/Http.roc

@@ -56,19 +56,32 @@ header = \(name, value) -> { name, value }
 ## ```
 ## # Prints out the HTML of the Roc-lang website.
 ## response =
-##     Http.send!({ Http.default_request & url: "https://www.roc-lang.org" })
+##     Http.send!({ Http.default_request & url: "https://www.roc-lang.org" })?
 ##
-## response.body
-## |> Str.from_utf8
+##
+## Str.from_utf8(response.body)
 ## |> Result.with_default("Invalid UTF-8")
 ## |> Stdout.line
 ## ```
-send! : Request => Response
+send! : Request => Result Response [HttpErr [Timeout, NetworkError, BadBody, Other (List U8)]]
 send! = \request ->
-    request
-    |> InternalHttp.to_host_request
-    |> Host.send_request!
-    |> InternalHttp.from_host_response
+
+    host_request = InternalHttp.to_host_request(request)
+
+    response = Host.send_request!(host_request) |> InternalHttp.from_host_response
+
+    other_error_prefix = Str.to_utf8("OTHER ERROR\n")
+
+    if response.status == 408 && response.body == Str.to_utf8("Request Timeout") then
+        Err(HttpErr Timeout)
+    else if response.status == 500 && response.body == Str.to_utf8("Network Error") then
+        Err(HttpErr NetworkError)
+    else if response.status == 500 && response.body == Str.to_utf8("Bad Body") then
+        Err(HttpErr BadBody)
+    else if response.status == 500 && List.starts_with(response.body, other_error_prefix) then
+        Err(HttpErr (Other List.drop_first(response.body, List.len(other_error_prefix))))
+    else
+        Ok(response)
 
 ## Try to perform an HTTP get request and convert (decode) the received bytes into a Roc type.
 ## Very useful for working with Json.
@@ -79,16 +92,16 @@ send! = \request ->
 ## # On the server side we send `Encode.to_bytes {foo: "Hello Json!"} Json.utf8`
 ## { foo } = Http.get!("http://localhost:8000", Json.utf8)?
 ## ```
-get! : Str, fmt => Result body [HttpDecodingFailed] where body implements Decoding, fmt implements DecoderFormatting
+get! : Str, fmt => Result body [HttpDecodingFailed, HttpErr _] where body implements Decoding, fmt implements DecoderFormatting
 get! = \uri, fmt ->
-    response = send!({ default_request & uri })
+    response = send!({ default_request & uri })?
 
     Decode.from_bytes(response.body, fmt)
     |> Result.map_err(\_ -> HttpDecodingFailed)
 
-get_utf8! : Str => Result Str [BadBody Str]
+get_utf8! : Str => Result Str [BadBody Str, HttpErr _]
 get_utf8! = \uri ->
-    response = send!({ default_request & uri })
+    response = send!({ default_request & uri })?
 
     response.body
     |> Str.from_utf8