Add skill versioning and version management (#44)

Add semver parsing, bumping, and comparison in internal/skill/version.go.
Add `skern skill version` command with --bump patch|minor|major support.
Add --version flag to `skern skill create` for setting initial version.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: devrimcavusoglu

internal/cli/skill.go

@@ -21,6 +21,7 @@ func newSkillCmd() *cobra.Command {
 	cmd.AddCommand(newSkillInstallCmd())
 	cmd.AddCommand(newSkillUninstallCmd())
 	cmd.AddCommand(newSkillRecommendCmd())
+	cmd.AddCommand(newSkillVersionCmd())
 
 	return cmd
 }

internal/cli/skill_create.go

@@ -22,6 +22,7 @@ func newSkillCreateCmd() *cobra.Command {
 		force          bool
 		fromTemplate   string
 		tags           []string
+		version        string
 	)
 
 	cmd := &cobra.Command{
@@ -105,6 +106,13 @@ func newSkillCreateCmd() *cobra.Command {
 			s := skill.NewSkillWithBody(name, description, author, authorType, authorPlatform, body)
 			s.Tags = tags
 
+			if version != "" {
+				if _, err := skill.ParseVersion(version); err != nil {
+					return &ValidationError{Message: err.Error()}
+				}
+				s.Metadata.Version = version
+			}
+
 			// Validate on create (warnings only, don't block)
 			issues := skill.Validate(s)
 			if len(issues) > 0 {
@@ -136,6 +144,7 @@ func newSkillCreateCmd() *cobra.Command {
 	cmd.Flags().BoolVar(&force, "force", false, "bypass overlap detection block")
 	cmd.Flags().StringVar(&fromTemplate, "from-template", "", "path to a template file for the skill body")
 	cmd.Flags().StringSliceVar(&tags, "tags", nil, "comma-separated tags for the skill")
+	cmd.Flags().StringVar(&version, "version", "", "initial version (default: 0.1.0)")
 
 	return cmd
 }

internal/cli/skill_version.go

@@ -0,0 +1,84 @@
+package cli
+
+import (
+	"fmt"
+	"path/filepath"
+
+	"github.com/devrimcavusoglu/skern/internal/output"
+	"github.com/devrimcavusoglu/skern/internal/skill"
+	"github.com/spf13/cobra"
+)
+
+func newSkillVersionCmd() *cobra.Command {
+	var (
+		scope string
+		bump  string
+	)
+
+	cmd := &cobra.Command{
+		Use:   "version <name>",
+		Short: "Show or bump a skill's version",
+		Long:  "Display the current version of a skill, or bump it with --bump patch|minor|major.",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			ctx := getContext(cmd)
+			name := args[0]
+
+			reg, err := ctx.NewRegistry()
+			if err != nil {
+				return err
+			}
+
+			s, skillDir, foundScope, err := resolveSkill(reg, name, scope)
+			if err != nil {
+				return err
+			}
+
+			if bump == "" {
+				// Show current version
+				result := output.SkillVersionResult{
+					Name:    name,
+					Version: s.Metadata.Version,
+					Scope:   string(foundScope),
+					Bumped:  false,
+				}
+				text := fmt.Sprintf("%s\n", s.Metadata.Version)
+				ctx.Printer.PrintResult(result, text)
+				return nil
+			}
+
+			// Validate bump level
+			if bump != "patch" && bump != "minor" && bump != "major" {
+				return &ValidationError{Message: fmt.Sprintf("invalid bump level %q: must be patch, minor, or major", bump)}
+			}
+
+			previousVersion := s.Metadata.Version
+			newVersion, err := skill.BumpVersion(previousVersion, bump)
+			if err != nil {
+				return fmt.Errorf("bumping version: %w", err)
+			}
+
+			s.Metadata.Version = newVersion
+			manifestPath := filepath.Join(skillDir, "SKILL.md")
+			if err := skill.WriteManifest(s, manifestPath); err != nil {
+				return fmt.Errorf("writing manifest: %w", err)
+			}
+
+			result := output.SkillVersionResult{
+				Name:            name,
+				Version:         newVersion,
+				Scope:           string(foundScope),
+				PreviousVersion: previousVersion,
+				Bumped:          true,
+			}
+			text := fmt.Sprintf("Bumped %q from %s to %s (%s)\n", name, previousVersion, newVersion, bump)
+			ctx.Printer.PrintResult(result, text)
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVar(&scope, "scope", "", "skill scope (user or project)")
+	cmd.Flags().StringVar(&bump, "bump", "", "bump level: patch, minor, or major")
+
+	return cmd
+}

internal/cli/skill_version_test.go

@@ -0,0 +1,224 @@
+package cli
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/devrimcavusoglu/skern/internal/output"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// --- skill version (show) ---
+
+func TestSkillVersion_Show(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "ver-skill", "--description", "A skill")
+	require.NoError(t, err)
+
+	out, err := runCmd(t, cc, "skill", "version", "ver-skill", "--json")
+	require.NoError(t, err)
+
+	var result output.SkillVersionResult
+	require.NoError(t, json.Unmarshal([]byte(out), &result))
+	assert.Equal(t, "ver-skill", result.Name)
+	assert.Equal(t, "0.1.0", result.Version)
+	assert.Equal(t, "user", result.Scope)
+	assert.False(t, result.Bumped)
+}
+
+func TestSkillVersion_Show_Text(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "ver-text", "--description", "A skill")
+	require.NoError(t, err)
+
+	out, err := runCmd(t, cc, "skill", "version", "ver-text")
+	require.NoError(t, err)
+	assert.Contains(t, out, "0.1.0")
+}
+
+func TestSkillVersion_NotFound(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "version", "nonexistent")
+	assert.Error(t, err)
+}
+
+// --- skill version --bump ---
+
+func TestSkillVersion_BumpPatch(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "bump-patch", "--description", "A skill")
+	require.NoError(t, err)
+
+	out, err := runCmd(t, cc, "skill", "version", "bump-patch", "--bump", "patch", "--json")
+	require.NoError(t, err)
+
+	var result output.SkillVersionResult
+	require.NoError(t, json.Unmarshal([]byte(out), &result))
+	assert.Equal(t, "bump-patch", result.Name)
+	assert.Equal(t, "0.1.1", result.Version)
+	assert.Equal(t, "0.1.0", result.PreviousVersion)
+	assert.True(t, result.Bumped)
+
+	// Verify the change persisted
+	showOut, err := runCmd(t, cc, "skill", "show", "bump-patch", "--json")
+	require.NoError(t, err)
+
+	var showResult output.SkillResult
+	require.NoError(t, json.Unmarshal([]byte(showOut), &showResult))
+	assert.Equal(t, "0.1.1", showResult.Version)
+}
+
+func TestSkillVersion_BumpMinor(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "bump-minor", "--description", "A skill")
+	require.NoError(t, err)
+
+	out, err := runCmd(t, cc, "skill", "version", "bump-minor", "--bump", "minor", "--json")
+	require.NoError(t, err)
+
+	var result output.SkillVersionResult
+	require.NoError(t, json.Unmarshal([]byte(out), &result))
+	assert.Equal(t, "0.2.0", result.Version)
+	assert.Equal(t, "0.1.0", result.PreviousVersion)
+	assert.True(t, result.Bumped)
+}
+
+func TestSkillVersion_BumpMajor(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "bump-major", "--description", "A skill")
+	require.NoError(t, err)
+
+	out, err := runCmd(t, cc, "skill", "version", "bump-major", "--bump", "major", "--json")
+	require.NoError(t, err)
+
+	var result output.SkillVersionResult
+	require.NoError(t, json.Unmarshal([]byte(out), &result))
+	assert.Equal(t, "1.0.0", result.Version)
+	assert.Equal(t, "0.1.0", result.PreviousVersion)
+	assert.True(t, result.Bumped)
+}
+
+func TestSkillVersion_BumpInvalidLevel(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "bump-bad", "--description", "A skill")
+	require.NoError(t, err)
+
+	_, err = runCmd(t, cc, "skill", "version", "bump-bad", "--bump", "invalid")
+	assert.Error(t, err)
+}
+
+func TestSkillVersion_BumpText(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "bump-text", "--description", "A skill")
+	require.NoError(t, err)
+
+	out, err := runCmd(t, cc, "skill", "version", "bump-text", "--bump", "patch")
+	require.NoError(t, err)
+	assert.Contains(t, out, "Bumped")
+	assert.Contains(t, out, "0.1.0")
+	assert.Contains(t, out, "0.1.1")
+}
+
+func TestSkillVersion_MultipleBumps(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "multi-bump", "--description", "A skill")
+	require.NoError(t, err)
+
+	// Bump patch twice
+	_, err = runCmd(t, cc, "skill", "version", "multi-bump", "--bump", "patch")
+	require.NoError(t, err)
+	_, err = runCmd(t, cc, "skill", "version", "multi-bump", "--bump", "patch")
+	require.NoError(t, err)
+
+	out, err := runCmd(t, cc, "skill", "version", "multi-bump", "--json")
+	require.NoError(t, err)
+
+	var result output.SkillVersionResult
+	require.NoError(t, json.Unmarshal([]byte(out), &result))
+	assert.Equal(t, "0.1.2", result.Version)
+}
+
+func TestSkillVersion_Scoped(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "scoped-ver", "--scope", "project", "--description", "A skill")
+	require.NoError(t, err)
+
+	out, err := runCmd(t, cc, "skill", "version", "scoped-ver", "--scope", "project", "--json")
+	require.NoError(t, err)
+
+	var result output.SkillVersionResult
+	require.NoError(t, json.Unmarshal([]byte(out), &result))
+	assert.Equal(t, "project", result.Scope)
+	assert.Equal(t, "0.1.0", result.Version)
+}
+
+// --- skill create --version ---
+
+func TestSkillCreate_WithVersion(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "versioned-skill",
+		"--description", "A skill", "--version", "0.2.0")
+	require.NoError(t, err)
+
+	out, err := runCmd(t, cc, "skill", "show", "versioned-skill", "--json")
+	require.NoError(t, err)
+
+	var result output.SkillResult
+	require.NoError(t, json.Unmarshal([]byte(out), &result))
+	assert.Equal(t, "0.2.0", result.Version)
+}
+
+func TestSkillCreate_WithVersion_JSON(t *testing.T) {
+	cc := testRegistry(t)
+
+	out, err := runCmd(t, cc, "skill", "create", "ver-json-skill",
+		"--description", "A skill", "--version", "1.0.0", "--json")
+	require.NoError(t, err)
+
+	var createResult output.SkillCreateResult
+	require.NoError(t, json.Unmarshal([]byte(out), &createResult))
+	assert.Equal(t, "ver-json-skill", createResult.Name)
+
+	// Verify version was set
+	showOut, err := runCmd(t, cc, "skill", "show", "ver-json-skill", "--json")
+	require.NoError(t, err)
+
+	var showResult output.SkillResult
+	require.NoError(t, json.Unmarshal([]byte(showOut), &showResult))
+	assert.Equal(t, "1.0.0", showResult.Version)
+}
+
+func TestSkillCreate_WithVersion_Invalid(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "bad-ver-skill",
+		"--description", "A skill", "--version", "bad")
+	assert.Error(t, err)
+}
+
+func TestSkillCreate_DefaultVersion(t *testing.T) {
+	cc := testRegistry(t)
+
+	_, err := runCmd(t, cc, "skill", "create", "default-ver",
+		"--description", "A skill")
+	require.NoError(t, err)
+
+	out, err := runCmd(t, cc, "skill", "show", "default-ver", "--json")
+	require.NoError(t, err)
+
+	var result output.SkillResult
+	require.NoError(t, json.Unmarshal([]byte(out), &result))
+	assert.Equal(t, "0.1.0", result.Version)
+}

internal/output/types_skill.go

@@ -106,3 +106,20 @@ type SkillValidateResult struct {
 	Warns  int                     `json:"warnings"`
 	Hints  int                     `json:"hints"`
 }
+
+// SkillVersionResult is the JSON envelope for skill version output.
+type SkillVersionResult struct {
+	Name            string `json:"name"`
+	Version         string `json:"version"`
+	Scope           string `json:"scope"`
+	PreviousVersion string `json:"previous_version,omitempty"`
+	Bumped          bool   `json:"bumped"`
+}
+
+// VersionCompareResult is the JSON envelope for version comparison output.
+type VersionCompareResult struct {
+	Installed string `json:"installed"`
+	Available string `json:"available"`
+	Kind      string `json:"kind,omitempty"`
+	Upgrade   bool   `json:"upgrade"`
+}