From 94f29ebdf119a5cac32acbe22a80fc149fe787f8 Mon Sep 17 00:00:00 2001
From: syumai <syumai@gmail.com>
Date: Thu, 1 Feb 2024 09:33:52 +0900
Subject: [PATCH] move fetch's stream logic to jshttp.ToStreamResponse

---
 cloudflare/fetch/bind.go    | 16 +---------------
 internal/jshttp/response.go | 34 +++++++++++++++++++++++++---------
 2 files changed, 26 insertions(+), 24 deletions(-)

diff --git a/cloudflare/fetch/bind.go b/cloudflare/fetch/bind.go
index 28c08e5..72e69dd 100644
--- a/cloudflare/fetch/bind.go
+++ b/cloudflare/fetch/bind.go
@@ -3,7 +3,6 @@ package fetch
 import (
 	"errors"
 	"net/http"
-	"strconv"
 	"syscall/js"
 
 	"github.com/syumai/workers/internal/jshttp"
@@ -31,18 +30,5 @@ func fetch(namespace js.Value, req *http.Request, init *RequestInit) (*http.Resp
 		return nil, err
 	}
 
-	// Create TransformStream
-	ts := js.Global().Get("IdentityTransformStream").New()
-	readable := ts.Get("readable")
-	writable := ts.Get("writable")
-	jsRes.Get("body").Call("pipeTo", writable)
-
-	// Create response
-	res := new(http.Response)
-	res.StatusCode = jsRes.Get("status").Int()
-	res.Status = strconv.Itoa(res.StatusCode) + " " + jsRes.Get("statusText").String()
-	res.Header = jshttp.ToHeader(jsRes.Get("headers"))
-	res.Body = jsutil.ConvertReadableStreamToReadCloser(readable)
-
-	return res, nil
+	return jshttp.ToStreamResponse(jsRes)
 }
diff --git a/internal/jshttp/response.go b/internal/jshttp/response.go
index 3f48c34..407ee37 100644
--- a/internal/jshttp/response.go
+++ b/internal/jshttp/response.go
@@ -9,15 +9,8 @@ import (
 	"github.com/syumai/workers/internal/jsutil"
 )
 
-// ToResponse converts JavaScript sides Response to *http.Response.
-//   - Response: https://developer.mozilla.org/docs/Web/API/Response
-func ToResponse(res js.Value) (*http.Response, error) {
+func toResponse(res js.Value, body io.ReadCloser) (*http.Response, error) {
 	status := res.Get("status").Int()
-	promise := res.Call("blob")
-	blob, err := jsutil.AwaitPromise(promise)
-	if err != nil {
-		return nil, err
-	}
 	header := ToHeader(res.Get("headers"))
 	contentLength, _ := strconv.ParseInt(header.Get("Content-Length"), 10, 64)
 
@@ -25,11 +18,34 @@ func ToResponse(res js.Value) (*http.Response, error) {
 		Status:        strconv.Itoa(status) + " " + res.Get("statusText").String(),
 		StatusCode:    status,
 		Header:        header,
-		Body:          jsutil.ConvertReadableStreamToReadCloser(blob.Call("stream")),
+		Body:          body,
 		ContentLength: contentLength,
 	}, nil
 }
 
+// ToResponse converts JavaScript sides Response to *http.Response.
+//   - Response: https://developer.mozilla.org/docs/Web/API/Response
+func ToResponse(res js.Value) (*http.Response, error) {
+	promise := res.Call("blob")
+	blob, err := jsutil.AwaitPromise(promise)
+	if err != nil {
+		return nil, err
+	}
+	body := jsutil.ConvertReadableStreamToReadCloser(blob.Call("stream"))
+	return toResponse(res, body)
+}
+
+// ToStreamResponse pipes JavaScript sides Response to TransformStream and converts to *http.Response.
+//   - see: https://developers.cloudflare.com/workers/runtime-apis/streams/
+func ToStreamResponse(res js.Value) (*http.Response, error) {
+	ts := js.Global().Get("IdentityTransformStream").New()
+	readable := ts.Get("readable")
+	writable := ts.Get("writable")
+	res.Get("body").Call("pipeTo", writable)
+	body := jsutil.ConvertReadableStreamToReadCloser(readable)
+	return toResponse(res, body)
+}
+
 // ToJSResponse converts *http.Response to JavaScript sides Response class object.
 func ToJSResponse(res *http.Response) js.Value {
 	return newJSResponse(res.StatusCode, res.Header, res.Body, nil)