Merge pull request #31 from aki-0421/fetch-transport

Add ability to use fetch as a http.Client

cloudflare/fetch/bind.go

@@ -0,0 +1,33 @@
+package fetch
+
+import (
+	"errors"
+	"net/http"
+	"syscall/js"
+
+	"github.com/syumai/workers/internal/jshttp"
+	"github.com/syumai/workers/internal/jsutil"
+)
+
+// fetch is a function that reproduces cloudflare fetch.
+// Docs: https://developers.cloudflare.com/workers/runtime-apis/fetch/
+func fetch(namespace js.Value, req *http.Request /* TO DO: options here */) (*http.Response, error) {
+	if namespace.IsUndefined() {
+		return nil, errors.New("fetch function not found")
+	}
+
+	promise := namespace.Call("fetch",
+		// The Request object to fetch.
+		// Docs: https://developers.cloudflare.com/workers/runtime-apis/request
+		jshttp.ToJSRequest(req),
+		// The content of the request.
+		// Docs: https://developers.cloudflare.com/workers/runtime-apis/request#requestinit
+		jsutil.NewObject(),
+	)
+	jsRes, err := jsutil.AwaitPromise(promise)
+	if err != nil {
+		return nil, err
+	}
+
+	return jshttp.ToResponse(jsRes)
+}

cloudflare/fetch/client.go

@@ -1,6 +1,7 @@
 package fetch
 
 import (
+	"net/http"
 	"syscall/js"
 
 	"github.com/syumai/workers/internal/jsutil"
@@ -19,6 +20,15 @@ func (c *Client) applyOptions(opts []ClientOption) {
 	}
 }
 
+// HTTPClient returns *http.Client.
+func (c *Client) HTTPClient() *http.Client {
+	return &http.Client{
+		Transport: &transport{
+			namespace: c.namespace,
+		},
+	}
+}
+
 // ClientOption is a type that represents an optional function.
 type ClientOption func(*Client)
 

cloudflare/fetch/http.go

@@ -2,21 +2,9 @@ package fetch
 
 import (
 	"net/http"
-
-	"github.com/syumai/workers/internal/jshttp"
-	"github.com/syumai/workers/internal/jsutil"
 )
 
 // Do sends an HTTP request and returns an HTTP response
 func (c *Client) Do(req *Request) (*http.Response, error) {
-	jsReq := jshttp.ToJSRequest(req.Request)
-
-	init := jsutil.NewObject()
-	promise := c.namespace.Call("fetch", jsReq, init)
-	jsRes, err := jsutil.AwaitPromise(promise)
-	if err != nil {
-		return nil, err
-	}
-
-	return jshttp.ToResponse(jsRes)
+	return fetch(c.namespace, req.Request)
 }

cloudflare/fetch/transport.go

@@ -0,0 +1,17 @@
+package fetch
+
+import (
+	"net/http"
+	"syscall/js"
+)
+
+// transport is an implementation of http.RoundTripper
+type transport struct {
+	// namespace - Objects that Fetch API belongs to. Default is Global
+	namespace js.Value
+}
+
+// RoundTrip replaces http.DefaultTransport.RoundTrip to use cloudflare fetch
+func (t *transport) RoundTrip(req *http.Request) (*http.Response, error) {
+	return fetch(t.namespace, req)
+}

examples/service-bindings/Makefile

@@ -5,7 +5,8 @@ dev:
 .PHONY: build
 build:
 	mkdir -p dist
-	tinygo build -o ./dist/app.wasm -target wasm ./...
+	#tinygo build -o ./dist/app.wasm -target wasm ./...
+	tinygo build -o ./dist/app.wasm -target wasm -no-debug ./...
 
 .PHONY: publish
 publish:

examples/service-bindings/main.go

@@ -13,17 +13,11 @@ import (
 func main() {
 	handler := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 		ctx := req.Context()
+		bind := cloudflare.GetBinding(ctx, "hello")
+		fc := fetch.NewClient(fetch.WithBinding(bind))
 
-		obj := cloudflare.GetBinding(ctx, "hello")
-		cli := fetch.NewClient(fetch.WithBinding(obj))
-		r, err := fetch.NewRequest(ctx, http.MethodGet, req.URL.String(), nil)
-		if err != nil {
-			fmt.Println(err)
-			w.WriteHeader(http.StatusInternalServerError)
-			return
-		}
-
-		res, err := cli.Do(r)
+		hc := fc.HTTPClient()
+		res, err := hc.Do(req)
 		if err != nil {
 			fmt.Println(err)
 			w.WriteHeader(http.StatusInternalServerError)