chore: add integration testing for service bindings

Adds integration testing for service bindings by creating a new worker
in the worker-sandbox directory and mounting it with Miniflare.

worker-sandbox/remote-service/package.json

@@ -0,0 +1,3 @@
+{
+    "main": "./service.js"
+}

worker-sandbox/remote-service/service.js

@@ -0,0 +1,3 @@
+addEventListener('fetch', event => {
+    event.respondWith(new Response('hello world'))
+})

worker-sandbox/remote-service/wrangler.toml

@@ -0,0 +1,2 @@
+name = "remote-service"
+type = "javascript"

worker-sandbox/src/lib.rs

@@ -646,6 +646,17 @@ pub async fn main(req: Request, env: Env, _ctx: worker::Context) -> Result<Respo
                 Ok(resp)
             }
         })
+        .get_async("/remote-by-request", |req, ctx| async move {
+            let fetcher = ctx.service("remote")?;
+            fetcher.fetch_request(req).await
+        })
+        .get_async("/remote-by-path", |req, ctx| async move {
+            let fetcher = ctx.service("remote")?;
+            let mut init = RequestInit::new();
+            init.with_method(Method::Post);
+
+            fetcher.fetch(req.url()?.to_string(), Some(init)).await
+        })
         .or_else_any_method_async("/*catchall", |_, ctx| async move {
             console_log!(
                 "[or_else_any_method_async] caught: {}",

worker-sandbox/tests/requests.rs

@@ -469,3 +469,12 @@ fn cache_api() {
     let body: serde_json::Value = post(delete_endpoint.as_str(), |r| r).json().unwrap();
     assert_eq!("ResponseNotFound", body);
 }
+
+#[test]
+fn test_service_binding() {
+    let body: String = get("remote-by-request", |r| r).text().unwrap();
+    assert_eq!(body, "hello world");
+
+    let body: String = get("remote-by-path", |r| r).text().unwrap();
+    assert_eq!(body, "hello world");
+}

worker-sandbox/wrangler.toml

@@ -11,6 +11,13 @@ kv_namespaces = [
 
 vars = { SOME_VARIABLE = "some value" }
 
+[[services]]
+binding = "remote"
+service = "remote-service"
+
+[miniflare.mounts]
+remote-service = "./remote-service"
+
 [durable_objects]
 bindings = [{ name = "COUNTER", class_name = "Counter" }, { name = "ALARM", class_name = "AlarmObject" }]
 

worker/src/fetcher.rs

@@ -2,19 +2,19 @@ use wasm_bindgen::{JsCast, JsValue};
 use wasm_bindgen_futures::JsFuture;
 use worker_sys::{Fetcher as FetcherSys, Response as ResponseSys};
 
-use crate::{Request, RequestInit, Response, Result, env::EnvBinding};
+use crate::{env::EnvBinding, Request, RequestInit, Response, Result};
 
 /// A struct for invoking fetch events to other Workers.
 pub struct Fetcher(FetcherSys);
 
 impl Fetcher {
-    /// Invoke a fetch event in a worker with a path and optionally a [RequestInit].
+    /// Invoke a fetch event in a worker with a url and optionally a [RequestInit].
     pub async fn fetch(
         &self,
-        path: impl Into<String>,
+        url: impl Into<String>,
         init: Option<RequestInit>,
     ) -> Result<Response> {
-        let path = path.into();
+        let path = url.into();
         let promise = match init {
             Some(ref init) => self.0.fetch_with_str_and_init(&path, &init.into()),
             None => self.0.fetch_with_str(&path),

worker/src/router.rs

@@ -10,7 +10,7 @@ use crate::{
     http::Method,
     request::Request,
     response::Response,
-    Result, Fetcher,
+    Fetcher, Result,
 };
 
 type HandlerFn<D> = fn(Request, RouteContext<D>) -> Result<Response>;