add javascript processor

internal/processing/debug-js.go

@@ -0,0 +1,65 @@
+package processing
+
+import (
+	"context"
+	"fmt"
+
+	"modernc.org/quickjs"
+)
+
+// NOTE(jwetzell): see language definition https://expr-lang.org/docs/language-definition
+type DebugJS struct {
+	config  ProcessorConfig
+	Program string
+}
+
+func (dl *DebugJS) Process(ctx context.Context, payload any) (any, error) {
+
+	vm, err := quickjs.NewVM()
+
+	if err != nil {
+		return nil, err
+	}
+	defer vm.Close()
+	payloadAtom, err := vm.NewAtom("payload")
+
+	if err != nil {
+		return nil, err
+	}
+
+	vm.SetProperty(vm.GlobalObject(), payloadAtom, payload)
+
+	output, err := vm.Eval(dl.Program, quickjs.EvalGlobal)
+	if err != nil {
+		return nil, err
+	}
+
+	return output, nil
+}
+
+func (dl *DebugJS) Type() string {
+	return dl.config.Type
+}
+
+func init() {
+	RegisterProcessor(ProcessorRegistration{
+		Type: "debug.js",
+		New: func(config ProcessorConfig) (Processor, error) {
+			params := config.Params
+
+			program, ok := params["program"]
+
+			if !ok {
+				return nil, fmt.Errorf("debug.js requires a program parameter")
+			}
+
+			programString, ok := program.(string)
+
+			if !ok {
+				return nil, fmt.Errorf("debug.js program must be a string")
+			}
+
+			return &DebugJS{config: config, Program: programString}, nil
+		},
+	})
+}