WIP: json using reqwest/serde

native/Cargo.toml

@@ -11,6 +11,11 @@ crate-type = ["cdylib"]
 [dependencies]
 rustler = "0.22.0"
 rustler_codegen = "0.22.0"
+bytes = "1.0.1"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+serde_rustler = { git = "https://github.com/satoren/serde_rustler", branch = "rustler_0.22" }
+serde-transcode = "1.1"
 lazy_static = "1.0.0"
 reqwest = { version = "0.11", features = ["native-tls", "cookies"] }
 tokio = { version = "1", features = ["rt-multi-thread", "sync"] }

native/src/lib.rs

@@ -9,6 +9,7 @@ use std::sync::RwLock;
 use std::thread;
 use std::time::Duration;
 use tokio::runtime::{Handle, Runtime};
+use bytes::BufMut;
 
 mod atoms {
     rustler::atoms! {
@@ -26,6 +27,7 @@ mod atoms {
         headers,
         https_only,
         identity,
+        json,
         method,
         ok,
         pool_idle_timeout,
@@ -333,7 +335,14 @@ fn req_async_internal(
     };
     if let Ok(term) = req.map_get(atoms::body().encode(env)) {
         req_builder = req_builder.body(term.decode::<Binary>()?.as_slice().to_owned());
-    };
+    } else if let Ok(term) = req.map_get(atoms::json().encode(env)) {
+        let mut buf = vec![].writer();
+        serde_transcode::transcode(
+            serde_rustler::Deserializer::from(term),
+            &mut serde_json::Serializer::new(&mut buf)
+        ).or(Err(rustler::Error::RaiseAtom("json_encode_error")))?;
+        req_builder = req_builder.body(buf.into_inner());
+    }
     if let Ok(term) = req.map_get(atoms::timeout().encode(env)) {
         if let Some(timeout) = maybe_timeout(term.decode()?) {
             req_builder = req_builder.timeout(timeout);

src/erqwest.erl

@@ -45,10 +45,12 @@
                 , method := method()
                 , headers => [header()]
                 , body => binary()
+                , json => term()
                 , timeout => timeout_ms()
                 }.
 -type req_opts() :: #{ headers => [header()]
                      , body => binary()
+                     , json => term()
                      , timeout => timeout_ms()
                      }.
 -type resp() :: #{ status := 100..599

test/erqwest_SUITE.erl

@@ -76,6 +76,7 @@ groups() ->
      , get_http
      , https_only
      , post
+     , json
      , timeout
      , timeout_default
      , timeout_infinity
@@ -143,6 +144,15 @@ post(_Config) ->
                   , body => <<"!@#$%^&*()">>}),
   #{<<"data">> := <<"!@#$%^&*()">>} = jsx:decode(Body).
 
+json(_Config) ->
+  Json = #{<<"data">> => <<"!@#$%^&*()">>},
+  {ok, #{status := 200, body := Body, headers := Headers}} =
+  erqwest:post(default, <<"https://httpbin.org/post">>,
+                 #{json => Json}),
+  #{<<"data">> := JsonData} = jsx:decode(Body),
+  {<<"content-type">>, <<"application/json">>} = proplists:lookup(<<"content-type">>, Headers),
+  Json = jsx:decode(JsonData).
+
 timeout(_Config) ->
   {error, #{code := timeout}} =
     erqwest:get(default, <<"https://httpbin.org/delay/1">>, #{timeout => 500}).