Pnpm suppport (#6)

* fix: resolves issues #3 and #4

* feat: add pnpm support & introduce pkg manager wrap for npm

cmd/npm/npm.go

@@ -0,0 +1,49 @@
+package npm
+
+import (
+	_ "embed"
+	"fmt"
+	"os"
+
+	"github.com/safedep/pmg/pkg/common/utils"
+	"github.com/safedep/pmg/pkg/registry"
+	"github.com/safedep/pmg/pkg/wrapper"
+	"github.com/spf13/cobra"
+)
+
+func NewNpmCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:                "npm [action] [package]",
+		Short:              "Scan packages from npm registry",
+		DisableFlagParsing: true,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			execPath, err := utils.GetExecutablePath(string(registry.RegistryNPM))
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "npm not found: %v\n", err)
+				return err
+			}
+
+			if len(args) >= 2 && utils.IsInstallCommand(string(registry.RegistryNPM), args[0]) {
+				if err := utils.ValidateEnvVars(); err != nil {
+					return err
+				}
+
+				pmw := wrapper.NewPackageManagerWrapper(registry.RegistryNPM)
+				pmw.Action = args[0]
+				pmw.PackageName = args[1]
+
+				if err := pmw.Wrap(); err != nil {
+					os.Exit(1)
+				}
+				return nil
+			}
+
+			if err := utils.ExecCmd(execPath, args, []string{}); err != nil {
+				os.Exit(1)
+			}
+			os.Exit(0)
+			return nil
+		},
+	}
+	return cmd
+}