fix: fix composition wrapper by adding URL.canParse to polyfill

composition-go/Makefile

@@ -0,0 +1,5 @@
+test:
+	go test -v ./...
+	go test -v -tags=wg_composition_v8 ./...
+
+.PHONY: test

composition-go/composition_test.go

@@ -35,6 +35,7 @@ var subgraphs = []*Subgraph{
 			name: String
 		  }`,
 		SubscriptionProtocol: "ws",
+		URL:                  "https://example.com/subgraph-a",
 	},
 	{
 		Name: "B",
@@ -58,6 +59,7 @@ var subgraphs = []*Subgraph{
 			age: Int @authenticated
 		  }`,
 		SubscriptionProtocol: "ws",
+		URL:                  "https://example.com/subgraph-b",
 	},
 }
 

composition-go/polyfill.go

@@ -62,3 +62,8 @@ func urlParse(rawURL string, base string) (*urlShim, error) {
 		Username: u.User.Username(),
 	}, nil
 }
+
+func urlCanParse(rawURL string, base string) bool {
+	_, err := urlParse(rawURL, base)
+	return err == nil
+}

composition-go/shim/src/polyfill.js

@@ -10,4 +10,8 @@ class URL {
             this[prop] = result[prop]
         }
     }
+
+    static canParse(url, base = undefined) {
+        return urlCanParse(url, base || '');
+    }
 }

composition-go/vm_goja.go

@@ -76,6 +76,10 @@ func newVM() (*gojaVm, error) {
 	if err := runtime.Set("urlParse", urlParse); err != nil {
 		return nil, err
 	}
+	if err := runtime.Set("urlCanParse", urlCanParse); err != nil {
+		return nil, err
+	}
+
 	return &gojaVm{
 		runtime:                  runtime,
 		federateSubgraphs:        federateSubgraphs,

composition-go/vm_v8.go

@@ -239,6 +239,20 @@ func urlParseV8(info *v8.FunctionCallbackInfo) *v8.Value {
 	return value
 }
 
+func urlCanParseV8(info *v8.FunctionCallbackInfo) *v8.Value {
+	isolate := info.Context().Isolate()
+	args := info.Args()
+	url := args[0].String()
+	base := args[1].String()
+
+	result := urlCanParse(url, base)
+	value, err := v8.NewValue(isolate, result)
+	if err != nil {
+		panic(err)
+	}
+	return value
+}
+
 func newVM() (*v8Vm, error) {
 	isolate := v8.NewIsolate()
 
@@ -254,6 +268,11 @@ func newVM() (*v8Vm, error) {
 		return nil, err
 	}
 
+	urlCanParse := v8.NewFunctionTemplate(isolate, urlCanParseV8)
+	if err := global.Set("urlCanParse", urlCanParse, v8.ReadOnly); err != nil {
+		return nil, err
+	}
+
 	ctx := v8.NewContext(isolate, global)
 
 	if _, err := ctx.RunScript(jsPrelude, "prelude.js"); err != nil {