add runtime context

cloudflare/env.go

@@ -1,10 +1,12 @@
 package cloudflare
 
-import "github.com/syumai/workers/internal/jsutil"
+import (
+	"context"
+)
 
 // Getenv gets a value of an environment variable.
 //   - https://developers.cloudflare.com/workers/platform/environment-variables/
-//   - Technically, this function is just an alias for js.Global().Get(env_name).String().
+//   - This function panics when a runtime context is not found.
-func Getenv(name string) string {
+func Getenv(ctx context.Context, name string) string {
-	return jsutil.Global.Get(name).String()
+	return getRuntimeContextEnv(ctx).Get(name).String()
 }

cloudflare/kv.go

@@ -1,6 +1,7 @@
 package cloudflare
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"syscall/js"
@@ -17,9 +18,10 @@ type KVNamespace struct {
 
 // NewKVNamespace returns KVNamespace for given variable name.
 //   - variable name must be defined in wrangler.toml as kv_namespace's binding.
-//   - if the given variable name doesn't exist on Global object, returns error.
+//   - if the given variable name doesn't exist on runtime context, returns error.
-func NewKVNamespace(varName string) (*KVNamespace, error) {
+//   - This function panics when a runtime context is not found.
-	inst := js.Global().Get(varName)
+func NewKVNamespace(ctx context.Context, varName string) (*KVNamespace, error) {
+	inst := getRuntimeContextEnv(ctx).Get(varName)
 	if inst.IsUndefined() {
 		return nil, fmt.Errorf("%s is undefined", varName)
 	}

cloudflare/r2bucket.go

@@ -1,6 +1,7 @@
 package cloudflare
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"syscall/js"
@@ -18,9 +19,10 @@ type R2Bucket struct {
 // NewR2Bucket returns R2Bucket for given variable name.
 //   - variable name must be defined in wrangler.toml.
 //   - see example: https://github.com/syumai/workers/tree/main/examples/r2-image-viewer
-//   - if the given variable name doesn't exist on Global object, returns error.
+//   - if the given variable name doesn't exist on runtime context, returns error.
-func NewR2Bucket(varName string) (*R2Bucket, error) {
+//   - This function panics when a runtime context is not found.
-	inst := js.Global().Get(varName)
+func NewR2Bucket(ctx context.Context, varName string) (*R2Bucket, error) {
+	inst := getRuntimeContextEnv(ctx).Get(varName)
 	if inst.IsUndefined() {
 		return nil, fmt.Errorf("%s is undefined", varName)
 	}

cloudflare/runtimecontext.go

@@ -0,0 +1,35 @@
+package cloudflare
+
+import (
+	"context"
+	"syscall/js"
+
+	"github.com/syumai/workers/internal/runtimecontext"
+)
+
+/**
+ *  The type definition of RuntimeContext for Cloudflare Worker expects:
+ *  ```ts
+ *  type RuntimeContext {
+ *    env: Env;
+ *    ctx: ExecutionContext;
+ *  }
+ *  ```
+ * This type is based on the type definition of ExportedHandlerFetchHandler.
+ * - see: https://github.com/cloudflare/workers-types/blob/c8d9533caa4415c2156d2cf1daca75289d01ae70/index.d.ts#LL564
+ */
+
+// getRuntimeContextEnv gets object which holds environment variables bound to Cloudflare worker.
+// - see: https://github.com/cloudflare/workers-types/blob/c8d9533caa4415c2156d2cf1daca75289d01ae70/index.d.ts#L566
+func getRuntimeContextEnv(ctx context.Context) js.Value {
+	runtimeCtxValue := runtimecontext.MustExtract(ctx)
+	return runtimeCtxValue.Get("env")
+}
+
+// getExecutionContext gets ExecutionContext object from context.
+// - see: https://github.com/cloudflare/workers-types/blob/c8d9533caa4415c2156d2cf1daca75289d01ae70/index.d.ts#L567
+// - see also: https://github.com/cloudflare/workers-types/blob/c8d9533caa4415c2156d2cf1daca75289d01ae70/index.d.ts#L554
+func getExecutionContext(ctx context.Context) js.Value {
+	runtimeCtxValue := runtimecontext.MustExtract(ctx)
+	return runtimeCtxValue.Get("ctx")
+}

handler.go

@@ -1,12 +1,14 @@
 package workers
 
 import (
+	"context"
 	"fmt"
 	"io"
 	"net/http"
 	"syscall/js"
 
 	"github.com/syumai/workers/internal/jsutil"
+	"github.com/syumai/workers/internal/runtimecontext"
 )
 
 var httpHandler http.Handler
@@ -14,15 +16,20 @@ var httpHandler http.Handler
 func init() {
 	var handleRequestCallback js.Func
 	handleRequestCallback = js.FuncOf(func(this js.Value, args []js.Value) any {
-		if len(args) != 1 {
+		if len(args) > 2 {
 			panic(fmt.Errorf("too many args given to handleRequest: %d", len(args)))
 		}
+		reqObj := args[0]
+		runtimeCtxObj := js.Null()
+		if len(args) > 1 {
+			runtimeCtxObj = args[1]
+		}
 		var cb js.Func
 		cb = js.FuncOf(func(_ js.Value, pArgs []js.Value) any {
 			defer cb.Release()
 			resolve := pArgs[0]
 			go func() {
-				res, err := handleRequest(args[0])
+				res, err := handleRequest(reqObj, runtimeCtxObj)
 				if err != nil {
 					panic(err)
 				}
@@ -36,7 +43,7 @@ func init() {
 }
 
 // handleRequest accepts a Request object and returns Response object.
-func handleRequest(reqObj js.Value) (js.Value, error) {
+func handleRequest(reqObj js.Value, runtimeCtxObj js.Value) (js.Value, error) {
 	if httpHandler == nil {
 		return js.Value{}, fmt.Errorf("Serve must be called before handleRequest.")
 	}
@@ -44,6 +51,8 @@ func handleRequest(reqObj js.Value) (js.Value, error) {
 	if err != nil {
 		panic(err)
 	}
+	ctx := runtimecontext.New(context.Background(), runtimeCtxObj)
+	req = req.WithContext(ctx)
 	reader, writer := io.Pipe()
 	w := &responseWriterBuffer{
 		header:     http.Header{},

internal/runtimecontext/context.go

@@ -0,0 +1,25 @@
+package runtimecontext
+
+import (
+	"context"
+	"errors"
+	"syscall/js"
+)
+
+type runtimeCtxKey struct{}
+
+func New(ctx context.Context, runtimeCtxObj js.Value) context.Context {
+	return context.WithValue(ctx, runtimeCtxKey{}, runtimeCtxObj)
+}
+
+var ErrRuntimeContextNotFound = errors.New("runtime context was not found")
+
+// MustExtract extracts runtime context object from context.
+// This function panics when runtime context object was not found.
+func MustExtract(ctx context.Context) js.Value {
+	v, ok := ctx.Value(runtimeCtxKey{}).(js.Value)
+	if !ok {
+		panic(ErrRuntimeContextNotFound)
+	}
+	return v
+}