feat: add next-version command

somebadcode · somebadcode · commit 4441f157e2f4 · 2025-06-15T01:38:46.000+02:00
diff --git a/cmd/app.go b/cmd/app.go
@@ -50,6 +50,7 @@ type CLI struct {
 
 	// Commands:
 	Lint        LintCommand        `kong:"cmd,default='',help='lint the commit messages in a git repository'"`
+	NextVersion NextVersionCommand `kong:"cmd,help='get next version (lint is recommended prior to running this)'"`
 	Version     VersionCommand     `kong:"cmd,help='show program version'"`
 }
 
diff --git a/cmd/nextversion.go b/cmd/nextversion.go
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2025 Tobias Dahlberg
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"log/slog"
+	"os"
+
+	"github.com/go-git/go-git/v5"
+	"github.com/go-git/go-git/v5/plumbing"
+
+	"github.com/somebadcode/commit-tool/nextversion"
+)
+
+type NextVersionCommand struct {
+	Repository     *git.Repository   `kong:"arg,placeholder='path',default='.',help='repository to lint'"`
+	Revision       plumbing.Revision `kong:"arg,name='revision',aliases='rev',optional,default='HEAD',placeholder='REVISION',help='revision to start at'"`
+	Output         string            `kong:"arg,type='path',default='-',help='where to output the next version'"`
+	VSuffix        bool              `kong:"default='true',negatable,help='output with v-suffix, i.e. v1.3.2'"`
+	WithPrerelease string            `kong:"optional,help='add prerelease information to tag'"`
+	WithMetadata   string            `kong:"optional,help='add metadata to tag'"`
+}
+
+func (cmd *NextVersionCommand) Run(ctx context.Context, l *slog.Logger) error {
+	var f io.WriteCloser
+	if cmd.Output == "-" {
+		f = os.Stdout
+	} else {
+		var err error
+		f, err = os.OpenFile(cmd.Output, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o666)
+		if err != nil {
+			return fmt.Errorf("opening output file: %w", err)
+		}
+
+		defer func() {
+			_ = f.Close()
+		}()
+	}
+
+	next := nextversion.NextVersion{
+		Repository: cmd.Repository,
+		Revision:   cmd.Revision,
+		VSuffix:    cmd.VSuffix,
+		Prerelease: cmd.WithPrerelease,
+		Metadata:   cmd.WithMetadata,
+		Writer:     f,
+		Logger:     l,
+	}
+
+	return next.Run(ctx)
+}
diff --git a/nextversion/nextversion.go b/nextversion/nextversion.go
@@ -0,0 +1,226 @@
+/*
+ * Copyright 2025 Tobias Dahlberg
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package nextversion
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"os"
+
+	"github.com/Masterminds/semver/v3"
+	"github.com/go-git/go-git/v5"
+	"github.com/go-git/go-git/v5/plumbing"
+	"github.com/go-git/go-git/v5/plumbing/object"
+	"github.com/go-git/go-git/v5/plumbing/storer"
+
+	"github.com/somebadcode/commit-tool/commitparser"
+)
+
+var (
+	ErrRepositoryRequired = errors.New("repository is required")
+)
+
+type NextVersion struct {
+	Repository *git.Repository
+	Revision   plumbing.Revision
+	Writer     io.Writer
+	Logger     *slog.Logger
+	Prerelease string
+	Metadata   string
+	VSuffix    bool
+}
+
+func (nv *NextVersion) Validate() error {
+	if nv.Repository == nil {
+		return ErrRepositoryRequired
+	}
+
+	if nv.Revision == "" {
+		nv.Revision = plumbing.Revision(plumbing.HEAD)
+	}
+
+	if nv.Logger == nil {
+		nv.Logger = slog.New(slog.DiscardHandler)
+	}
+
+	if nv.Writer == nil {
+		nv.Writer = os.Stdout
+	}
+
+	return nil
+}
+
+func (nv *NextVersion) Run(ctx context.Context) error {
+	if err := nv.Validate(); err != nil {
+		return err
+	}
+
+	hash, err := nv.Repository.ResolveRevision(nv.Revision)
+	if err != nil {
+		return fmt.Errorf("failed to resolve revision %q: %w", nv.Revision, err)
+	}
+
+	var iter object.CommitIter
+
+	iter, err = nv.Repository.Log(&git.LogOptions{
+		From:  *hash,
+		Order: git.LogOrderBSF,
+	})
+
+	if err != nil {
+		return fmt.Errorf("could not iterate over commits: %w", err)
+	}
+
+	var tags map[plumbing.Hash]*semver.Version
+
+	tags, err = findTags(ctx, nv.Repository)
+	if err != nil {
+		return fmt.Errorf("could not find tags: %w", err)
+	}
+
+	if len(tags) > 0 && nv.Logger.Enabled(ctx, slog.LevelDebug) {
+		attrs := make([]slog.Attr, len(tags))
+
+		for h, v := range tags {
+			attrs = append(attrs, slog.String(v.String(), h.String()))
+		}
+
+		nv.Logger.LogAttrs(ctx, slog.LevelDebug, "discovered tags",
+			slog.Any("tags", slog.GroupValue(attrs...)),
+		)
+	}
+
+	var major, minor, patch bool
+
+	var version *semver.Version
+
+	err = iter.ForEach(func(commit *object.Commit) error {
+		if ctx.Err() != nil {
+			if nv.Logger.Enabled(ctx, slog.LevelDebug) {
+				nv.Logger.LogAttrs(ctx, slog.LevelDebug, "cancelling finding tags",
+					slog.String("hash", commit.Hash.String()),
+					slog.String("cause", ctx.Err().Error()),
+				)
+			}
+
+			return ctx.Err()
+		}
+
+		if version = tags[commit.Hash]; version != nil {
+			return storer.ErrStop
+		}
+
+		var msg commitparser.CommitMessage
+
+		msg, err = commitparser.Parse(commit.Message)
+		if err != nil {
+			return fmt.Errorf("could not parse commit message: %w", err)
+		}
+
+		if msg.Breaking {
+			major = true
+
+			return nil
+		}
+
+		switch msg.Type {
+		case "feat":
+			minor = true
+		case "fix", "sec":
+			patch = true
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		return fmt.Errorf("failed to calculate next version: %w", err)
+	}
+
+	if version == nil {
+		version = semver.MustParse("0.0.0")
+	}
+
+	switch {
+	case major && version.Major() > 0:
+		*version = version.IncMajor()
+	case minor || (major && version.Major() > 0):
+		*version = version.IncMinor()
+	case patch:
+		*version = version.IncPatch()
+	}
+
+	*version, err = version.SetPrerelease(nv.Prerelease)
+	if err != nil {
+		return fmt.Errorf("could not set prerelease version: %w", err)
+	}
+
+	*version, err = version.SetMetadata(nv.Metadata)
+	if err != nil {
+		return fmt.Errorf("could not set metadata version: %w", err)
+	}
+
+	if nv.VSuffix {
+		_, err = nv.Writer.Write([]byte{'v'})
+		if err != nil {
+			return fmt.Errorf("could not write version suffix: %w", err)
+		}
+	}
+
+	_, err = nv.Writer.Write([]byte(version.String()))
+	if err != nil {
+		return fmt.Errorf("could not write next version: %w", err)
+	}
+
+	return nil
+}
+
+func findTags(ctx context.Context, repo *git.Repository) (map[plumbing.Hash]*semver.Version, error) {
+	iter, err := repo.Tags()
+	if err != nil {
+		return nil, fmt.Errorf("could not get tags: %w", err)
+	}
+
+	defer iter.Close()
+
+	tags := make(map[plumbing.Hash]*semver.Version)
+
+	err = iter.ForEach(func(ref *plumbing.Reference) error {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+
+		var v *semver.Version
+		v, err = semver.NewVersion(ref.Name().Short())
+		if err != nil {
+			return nil
+		}
+
+		tags[ref.Hash()] = v
+
+		return nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	return tags, nil
+}

Original file line number	Diff line number	Diff line change
`@@ -50,6 +50,7 @@ type CLI struct {`
`50`	`50`
`51`	`51`	`// Commands:`
`52`	`52`	Lint LintCommand `kong:"cmd,default='',help='lint the commit messages in a git repository'"`
	`53`	+ NextVersion NextVersionCommand `kong:"cmd,help='get next version (lint is recommended prior to running this)'"`
`53`	`54`	Version VersionCommand `kong:"cmd,help='show program version'"`
`54`	`55`	`}`
`55`	`56`