Add json method for Response

Cargo.toml

@@ -10,7 +10,16 @@ keywords = ["webassembly", "wasm", "wasi"]
 repository = "https://github.com/wacker-dev/wasi-http-client"
 license = "Apache-2.0"
 
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
 [dependencies]
 anyhow = "1.0.83"
 wasi = "0.13.0"
 url = "2.5.0"
+serde = { version = "1.0.201", optional = true }
+serde_json = { version = "1.0.117", optional = true }
+
+[features]
+json = ["dep:serde", "dep:serde_json"]

src/response.rs

@@ -1,4 +1,8 @@
 use anyhow::{anyhow, Result};
+#[cfg(feature = "json")]
+use serde::de::DeserializeOwned;
+#[cfg(feature = "json")]
+use serde_json;
 use std::collections::HashMap;
 use wasi::http::types::{IncomingResponse, StatusCode};
 use wasi::io::streams::StreamError;
@@ -57,4 +61,15 @@ impl Response {
     pub fn body(&self) -> &Vec<u8> {
         &self.body
     }
+
+    /// Deserialize the response body as JSON.
+    ///
+    /// # Optional
+    ///
+    /// This requires the `json` feature enabled.
+    #[cfg(feature = "json")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "json")))]
+    pub fn json<T: DeserializeOwned>(&self) -> Result<T> {
+        Ok(serde_json::from_slice(&self.body)?)
+    }
 }

tests/program/Cargo.toml

@@ -21,6 +21,7 @@ package = "component:wasi-http-client-test-program"
 "wasi:random" = { path = "wit/deps/random" }
 
 [dependencies]
-wasi-http-client = { path = "../../../wasi-http-client" }
+wasi-http-client = { path = "../../../wasi-http-client", features = ["json"] }
 
 wit-bindgen-rt = { version = "0.24.0", features = ["bitflags"] }
+serde = { version = "1.0.201", features = ["derive"] }

tests/program/src/lib.rs

@@ -2,13 +2,21 @@
 mod bindings;
 
 use bindings::exports::wasi::cli::run::Guest;
+use serde::Deserialize;
 use std::time::Duration;
 use wasi_http_client::Client;
 
 struct Component;
 
 bindings::export!(Component with_types_in bindings);
 
+#[derive(Debug, Deserialize)]
+#[allow(dead_code)]
+struct Data {
+    origin: String,
+    url: String,
+}
+
 impl Guest for Component {
     fn run() -> Result<(), ()> {
         // get with query
@@ -22,6 +30,15 @@ impl Guest for Component {
             String::from_utf8_lossy(resp.body())
         );
 
+        // get with json response
+        let resp = Client::new().get("https://httpbin.org/get").send().unwrap();
+        let json_data = resp.json::<Data>().unwrap();
+        println!(
+            "GET https://httpbin.org/get, status code: {}, body:\n{:?}\n",
+            resp.status(),
+            json_data,
+        );
+
         // post with json data
         let resp = Client::new()
             .post("https://httpbin.org/post")