add http caller example

Author: vedhavyas

bridge.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"log"
 	"math"
+	"net/http"
 	"reflect"
 	"sync"
 	"syscall"
@@ -107,7 +108,9 @@ func (b *Bridge) addValues() {
 		false,
 		&object{
 			props: map[string]interface{}{
-				"Object":       propObject("Object", nil),
+				"Object": &object{name: "Object", new: func(args []interface{}) interface{} {
+					return &object{name: "ObjectInner", props: map[string]interface{}{}}
+				}},
 				"Array":        propObject("Array", nil),
 				"Int8Array":    typedArray,
 				"Int16Array":   typedArray,
@@ -137,6 +140,28 @@ func (b *Bridge) addValues() {
 						return rand.Read(arr.data())
 					}),
 				}),
+				"AbortController": &object{name: "AbortController", new: func(args []interface{}) interface{} {
+					return &object{name: "AbortControllerInner", props: map[string]interface{}{
+						"signal": propObject("signal", map[string]interface{}{}),
+					}}
+				}},
+				"Headers": &object{name: "Headers", new: func(args []interface{}) interface{} {
+					headers := http.Header{}
+					obj := &object{name: "HeadersInner", props: map[string]interface{}{
+						"headers": headers,
+						"append": Func(func(args []interface{}) (interface{}, error) {
+							headers.Add(args[0].(string), args[1].(string))
+							return nil, nil
+						}),
+					}}
+
+					return obj
+				}},
+				"fetch": Func(func(args []interface{}) (interface{}, error) {
+					// TODO(ved): implement fetch
+					log.Fatalln(args)
+					return nil, nil
+				}),
 				"fs": propObject("fs", map[string]interface{}{
 					"constants": propObject("constants", map[string]interface{}{
 						"O_WRONLY": syscall.O_WRONLY,
@@ -494,6 +519,15 @@ func Bytes(v interface{}) ([]byte, error) {
 	return arr.data(), nil
 }
 
+func String(v interface{}) (string, error) {
+	str, ok := v.(string)
+	if !ok {
+		return "", fmt.Errorf("got %t instead of string", v)
+	}
+
+	return str, nil
+}
+
 func Error(v interface{}) (errVal error, err error) {
 	str, ok := v.(string)
 	if !ok {

examples/http-caller/main.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"context"
+	"log"
+
+	"github.com/vedhavyas/go-wasm"
+)
+
+func main() {
+	b, err := wasm.BridgeFromFile("test", "./examples/http/main.wasm", nil)
+	if err != nil {
+		panic(err)
+	}
+
+	ctx, canc := context.WithCancel(context.Background())
+	defer canc()
+	init := make(chan error)
+	go b.Run(ctx, init)
+	if err := <-init; err != nil {
+		panic(err)
+	}
+
+	res, err := b.CallFunc("call", []interface{}{"https://google.com"})
+	if err != nil {
+		panic(err)
+	}
+
+	str, err := wasm.String(res)
+	if err != nil {
+		panic(err)
+	}
+
+	log.Println("Result:", str)
+}

examples/http/main.go

@@ -0,0 +1,29 @@
+// +build js,wasm
+
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"syscall/js"
+)
+
+func call(this js.Value, args []js.Value) interface{} {
+	res, err := http.Get(args[0].String())
+	if err != nil {
+		panic(err)
+	}
+
+	f := fmt.Sprintln(res.Status, res.StatusCode, res.ContentLength)
+	err = res.Body.Close()
+	if err != nil {
+		panic(err)
+	}
+
+	return f
+}
+
+func main() {
+	js.Global().Set("call", js.FuncOf(call))
+	select {}
+}