Updated tests and add new functions for versioning

Signed-off-by: Mihael Rodek <mihael.rodek1@gmail.com>

cmd/helm/plugin_update.go

@@ -29,8 +29,7 @@ import (
 )
 
 type pluginUpdateOptions struct {
-	names   map[string]string
-	version string
+	names map[string]string
 }
 
 const pluginUpdateDesc = `
@@ -41,7 +40,7 @@ func newPluginUpdateCmd(out io.Writer) *cobra.Command {
 	o := &pluginUpdateOptions{}
 
 	cmd := &cobra.Command{
-		Use:     "update <plugin:[version]>...",
+		Use:     "update <plugin[:version]>...",
 		Aliases: []string{"up"},
 		Short:   "update one or more Helm plugins",
 		Long:    pluginUpdateDesc,
@@ -55,7 +54,6 @@ func newPluginUpdateCmd(out io.Writer) *cobra.Command {
 			return o.run(out)
 		},
 	}
-	cmd.Flags().StringVar(&o.version, "version", "", "specify a version constraint. If this is not specified, the latest version is installed")
 	return cmd
 }
 
@@ -109,7 +107,13 @@ func updatePlugin(p *plugin.Plugin, version string) error {
 		return err
 	}
 
-	i, err := installer.FindSource(absExactLocation, version)
+	var i installer.Installer
+
+	if version != "" {
+		i, err = installer.FindSourceWithVersion(absExactLocation, version)
+	} else {
+		i, err = installer.FindSource(absExactLocation)
+	}
 	if err != nil {
 		return err
 	}

pkg/plugin/installer/installer.go

@@ -75,8 +75,17 @@ func NewForSource(source, version string) (Installer, error) {
 }
 
 // FindSource determines the correct Installer for the given source.
-func FindSource(location, version string) (Installer, error) {
-	installer, err := existingVCSRepo(location, version)
+func FindSource(location string) (Installer, error) {
+	installer, err := existingVCSRepo(location)
+	if err != nil && err.Error() == "Cannot detect VCS" {
+		return installer, errors.New("cannot get information about plugin source")
+	}
+	return installer, err
+}
+
+// FindSourceWithVersion determines the correct Installer for the given source with provided version.
+func FindSourceWithVersion(location, version string) (Installer, error) {
+	installer, err := existingVCSRepoWithVersion(location, version)
 	if err != nil && err.Error() == "Cannot detect VCS" {
 		return installer, errors.New("cannot get information about plugin source")
 	}

pkg/plugin/installer/vcs_installer.go

@@ -16,11 +16,11 @@ limitations under the License.
 package installer // import "helm.sh/helm/v3/pkg/plugin/installer"
 
 import (
-	"github.com/Masterminds/vcs"
 	"os"
 	"sort"
 
 	"github.com/Masterminds/semver/v3"
+	"github.com/Masterminds/vcs"
 	"github.com/pkg/errors"
 
 	"helm.sh/helm/v3/internal/third_party/dep/fs"
@@ -35,7 +35,19 @@ type VCSInstaller struct {
 	base
 }
 
-func existingVCSRepo(location, version string) (Installer, error) {
+func existingVCSRepo(location string) (Installer, error) {
+	repo, err := vcs.NewRepo("", location)
+	if err != nil {
+		return nil, err
+	}
+	i := &VCSInstaller{
+		Repo: repo,
+		base: newBase(repo.Remote()),
+	}
+	return i, nil
+}
+
+func existingVCSRepoWithVersion(location, version string) (Installer, error) {
 	repo, err := vcs.NewRepo("", location)
 	if err != nil {
 		return nil, err