feat: check if we have already compiled agent

Author: NSEcho

main.go

@@ -17,6 +17,10 @@ import (
 	"syscall"
 )
 
+const (
+	agentFilename = "_agent.js"
+)
+
 //go:embed script.ts
 var scriptContent []byte
 
@@ -202,6 +206,15 @@ var rootCmd = &cobra.Command{
 
 		os.MkdirAll(tempDir, os.ModePerm)
 
+		// save current directory because we might change it to compile the script
+		currentDir, _ := os.Getwd()
+
+		if _, err = os.Stat(filepath.Join(tempDir, "script.ts")); os.IsNotExist(err) {
+			for fl, data := range tempFiles {
+				os.WriteFile(filepath.Join(tempDir, fl), data, os.ModePerm)
+			}
+		}
+
 		if _, err = os.Stat(filepath.Join(tempDir, "node_modules")); os.IsNotExist(err) {
 			// Install modules
 			command := exec.Command("npm", "install")
@@ -210,28 +223,40 @@ var rootCmd = &cobra.Command{
 			}
 		}
 
-		for fl, data := range tempFiles {
-			os.WriteFile(filepath.Join(tempDir, fl), data, os.ModePerm)
-		}
+		agentPath := filepath.Join(tempDir, agentFilename)
+		var scriptBody string
 
-		currentDir, _ := os.Getwd()
+		// check if we have script.ts already compiled
+		if _, err = os.Stat(agentPath); os.IsNotExist(err) {
+			os.Chdir(tempDir)
 
-		os.Chdir(tempDir)
+			comp := frida.NewCompiler()
 
-		comp := frida.NewCompiler()
+			comp.On("finished", func() {
+				logger.Infof("Done compiling script")
+			})
 
-		comp.On("finished", func() {
-			logger.Infof("Done compiling script")
-		})
+			bundle, err := comp.Build("script.ts")
+			if err != nil {
+				return fmt.Errorf("error compiling script: %v", err)
+			}
 
-		bundle, err := comp.Build("script.ts")
-		if err != nil {
-			logger.Errorf("Error compiling script: %v", err)
-		}
+			if err := os.WriteFile(agentPath, []byte(bundle), os.ModePerm); err != nil {
+				return fmt.Errorf("error saving agent script: %v", err)
+			}
 
-		os.Chdir(currentDir)
+			scriptBody = bundle
+
+			os.Chdir(currentDir)
+		} else {
+			data, err := os.ReadFile(agentPath)
+			if err != nil {
+				return fmt.Errorf("error reading agent script: %v", err)
+			}
+			scriptBody = string(data)
+		}
 
-		script, err := session.CreateScript(bundle)
+		script, err := session.CreateScript(scriptBody)
 		if err != nil {
 			return err
 		}