Initial commit: JavaScript to WebAssembly compilation comparison

- 5 different JS-to-WASM implementations analyzed
- QuickJS (283KB) and Javy Static (519KB) are Wasmer-compatible
- Comprehensive size analysis and runtime compatibility testing
- Complete documentation and build automation
- Wasmer v6.1.0-rc.2 dynamic linking analysis included

implementations/goja/main.go

@@ -0,0 +1,130 @@
+//go:build js && wasm
+// +build js,wasm
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"syscall/js"
+
+	"github.com/dop251/goja"
+)
+
+// promisify wraps a Go function to return a JavaScript Promise
+func promisify(fn func([]js.Value) (string, error)) js.Func {
+	return js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+		// Create a new Promise
+		handler := js.FuncOf(func(this js.Value, promiseArgs []js.Value) interface{} {
+			resolve := promiseArgs[0]
+			reject := promiseArgs[1]
+
+			// Run the function in a goroutine
+			go func() {
+				defer func() {
+					if r := recover(); r != nil {
+						errorConstructor := js.Global().Get("Error")
+						errorObj := errorConstructor.New(fmt.Sprintf("panic occurred: %v", r))
+						reject.Invoke(errorObj)
+					}
+				}()
+
+				// Pass the original args to the function, not the promise args
+				result, err := fn(args)
+				if err != nil {
+					errorConstructor := js.Global().Get("Error")
+					errorObj := errorConstructor.New(err.Error())
+					reject.Invoke(errorObj)
+				} else {
+					resolve.Invoke(result)
+				}
+			}()
+
+			return nil
+		})
+
+		promiseConstructor := js.Global().Get("Promise")
+		return promiseConstructor.New(handler)
+	})
+}
+
+// transformData takes a JSON string and JavaScript code, processes it using Goja JavaScript engine, and returns a JSON string
+func transformData(args []js.Value) (string, error) {
+	js.Global().Get("console").Call("log", "🔄 transformData called with", len(args), "arguments")
+
+	if len(args) < 2 {
+		return "", fmt.Errorf("expected two arguments: JSON string and JavaScript code")
+	}
+
+	// Get the input JSON string
+	inputJSON := args[0].String()
+	js.Global().Get("console").Call("log", "📥 Input JSON:", inputJSON)
+
+	// Get the JavaScript transformation code
+	transformJS := args[1].String()
+	js.Global().Get("console").Call("log", "📜 JavaScript code length:", len(transformJS), "characters")
+
+	// Parse the input JSON
+	var inputData interface{}
+	if err := json.Unmarshal([]byte(inputJSON), &inputData); err != nil {
+		return "", fmt.Errorf("failed to parse input JSON: %v", err)
+	}
+
+	// Create a new Goja runtime
+	vm := goja.New()
+
+	// Execute the JavaScript code to define the transform function
+	_, err := vm.RunString(transformJS)
+	if err != nil {
+		return "", fmt.Errorf("failed to execute JavaScript transformation code: %v", err)
+	}
+
+	// Get the transform function
+	transformFunc, ok := goja.AssertFunction(vm.Get("transform"))
+	if !ok {
+		return "", fmt.Errorf("transform function not found in JavaScript code")
+	}
+
+	// Convert Go data to Goja value
+	gojaInput := vm.ToValue(inputData)
+
+	// Call the JavaScript transform function
+	result, err := transformFunc(goja.Undefined(), gojaInput)
+	if err != nil {
+		return "", fmt.Errorf("JavaScript transformation failed: %v", err)
+	}
+
+	// Export the result back to Go
+	transformedData := result.Export()
+
+	// Convert back to JSON
+	outputJSON, err := json.Marshal(transformedData)
+	if err != nil {
+		return "", fmt.Errorf("failed to marshal output JSON: %v", err)
+	}
+
+	resultStr := string(outputJSON)
+	js.Global().Get("console").Call("log", "📤 Output JSON:", resultStr)
+
+	return resultStr, nil
+}
+
+func main() {
+	js.Global().Get("console").Call("log", "🚀 Go WASM module loaded (Goja implementation)")
+
+	// Expose the transformData function to JavaScript
+	js.Global().Set("transformData", promisify(transformData))
+
+	// Add a simple health check function
+	js.Global().Set("healthCheck", promisify(func(args []js.Value) (string, error) {
+		js.Global().Get("console").Call("log", "💓 Health check called")
+		return `{"status": "healthy", "message": "Go WASM module with Goja is running"}`, nil
+	}))
+
+	js.Global().Get("console").Call("log", "✅ Functions exposed to JavaScript:")
+	js.Global().Get("console").Call("log", "  - transformData(jsonString, jsCode)")
+	js.Global().Get("console").Call("log", "  - healthCheck()")
+
+	// Keep the program running
+	<-make(chan bool)
+}