added support .nvmrc

Before installing nvm, checks the availability of the .nvmrc file and, if it exists, takes the version from the .nvmrc file and overrides the version in the configuration

internal/manager/serverless/native.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strings"
 )
 
 func (sls *Manager) runNpmInstall(w io.Writer) error {
@@ -33,14 +34,25 @@ func (sls *Manager) runNvm(w io.Writer) error {
 	if len(nvmDir) == 0 {
 		nvmDir = "$HOME/.nvm"
 	}
+	var command string
+	_, err := os.Stat(filepath.Join(sls.App.Path, ".nvmrc"))
+	if os.IsNotExist(err) {
+		command = fmt.Sprintf("source %s/nvm.sh && nvm install %s", nvmDir, sls.App.NodeVersion)
 
-	command := fmt.Sprintf("source %s/nvm.sh && nvm install %s", nvmDir, sls.App.NodeVersion)
+	} else {
+		file, err := os.ReadFile(filepath.Join(sls.App.Path, ".nvmrc"))
+		if err != nil {
+			return fmt.Errorf("can't read .nvmrc: %w", err)
+		}
+		sls.App.NodeVersion = strings.TrimSpace(string(file))
+		command = fmt.Sprintf("source %s/nvm.sh && nvm install %s", nvmDir, sls.App.NodeVersion)
+	}
 
 	cmd := exec.Command("bash", "-c", command)
 	cmd.Stdout = w
 	cmd.Stderr = w
 	cmd.Dir = filepath.Join(sls.App.Path)
-	err := cmd.Run()
+	err = cmd.Run()
 	if err != nil {
 		return err
 	}