feature: Store lefthook checksum in non-hook file (#280)

* feature: Store lefthook checksum in non-hook file

Signed-off-by: Valentin Kiselev <mrexox@evilmartians.com>

* chore: Remove redundant code

Signed-off-by: Valentin Kiselev <mrexox@evilmartians.com>

* feature: Store commit hash in a version

Signed-off-by: Valentin Kiselev <mrexox@evilmartians.com>

Makefile

@@ -1,5 +1,7 @@
+COMMIT_HASH = $(shell git rev-parse HEAD)
+
 build:
-	go build -o lefthook
+	go build -ldflags "-X github.com/evilmartians/lefthook/internal/version.commit=$(COMMIT_HASH)" -o lefthook
 
 test:
 	go test -cpu 24 -race -count=1 -timeout=30s ./...

cmd/version.go

@@ -9,13 +9,20 @@ import (
 )
 
 func newVersionCmd(opts *lefthook.Options) *cobra.Command {
+	var verbose bool
+
 	versionCmd := cobra.Command{
 		Use:   "version",
 		Short: "Show lefthook version",
 		Run: func(cmd *cobra.Command, args []string) {
-			log.Println(version.Version)
+			log.Println(version.Version(verbose))
 		},
 	}
 
+	versionCmd.Flags().BoolVarP(
+		&verbose, "full", "f", false,
+		"full version with commit hash",
+	)
+
 	return &versionCmd
 }

internal/config/available_hooks.go

@@ -1,7 +1,10 @@
 package config
 
-// ChecksumHookName - git hook, which is used just to store the current config checksum version.
-const ChecksumHookName = "prepare-commit-msg"
+// ChecksumFileName - the file, which is used just to store the current config checksum version.
+const ChecksumFileName = "lefthook.checksum"
+
+// GhostHookName - the hook which logs are not shown and which is used for synchronizing hooks.
+const GhostHookName = "prepare-commit-msg"
 
 // AvailableHooks - list of hooks taken from https://git-scm.com/docs/githooks.
 var AvailableHooks = [...]string{

internal/git/repository.go

@@ -13,6 +13,7 @@ import (
 const (
 	cmdRootPath    = "git rev-parse --show-toplevel"
 	cmdHooksPath   = "git rev-parse --git-path hooks"
+	cmdInfoPath    = "git rev-parse --git-path info"
 	cmdGitPath     = "git rev-parse --git-dir"
 	cmdStagedFiles = "git diff --name-only --cached"
 	cmdAllFiles    = "git ls-files --cached"
@@ -25,6 +26,7 @@ type Repository struct {
 	HooksPath string
 	RootPath  string
 	GitPath   string
+	InfoPath  string
 }
 
 // NewRepository returns a Repository or an error, if git repository it not initialized.
@@ -42,6 +44,14 @@ func NewRepository(fs afero.Fs) (*Repository, error) {
 		hooksPath = filepath.Join(rootPath, hooksPath)
 	}
 
+	infoPath, err := execGit(cmdInfoPath)
+	if err != nil {
+		return nil, err
+	}
+	if exists, _ := afero.DirExists(fs, filepath.Join(rootPath, infoPath)); exists {
+		infoPath = filepath.Join(rootPath, infoPath)
+	}
+
 	gitPath, err := execGit(cmdGitPath)
 	if err != nil {
 		return nil, err
@@ -55,6 +65,7 @@ func NewRepository(fs afero.Fs) (*Repository, error) {
 		HooksPath: hooksPath,
 		RootPath:  rootPath,
 		GitPath:   gitPath,
+		InfoPath:  infoPath,
 	}, nil
 }
 

internal/lefthook/add.go

@@ -35,7 +35,7 @@ func (l *Lefthook) Add(args *AddArgs) error {
 		return err
 	}
 
-	err = l.addHook(args.Hook, "")
+	err = l.addHook(args.Hook)
 	if err != nil {
 		return err
 	}

internal/lefthook/install.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"path/filepath"
 	"regexp"
+	"strconv"
 	"strings"
 
 	"github.com/spf13/afero"
@@ -18,11 +19,14 @@ import (
 
 const (
 	configFileMode    = 0o666
+	checksumFileMode  = 0o644
 	configDefaultName = "lefthook.yml"
 	configGlob        = "lefthook.y*ml"
+	timestampBase     = 10
+	timestampBitsize  = 64
 )
 
-var lefthookChecksumRegexp = regexp.MustCompile(`(?:#\s*lefthook_version:\s+)(\w+)`)
+var lefthookChecksumRegexp = regexp.MustCompile(`(\w+)\s+(\d+)`)
 
 type InstallArgs struct {
 	Force, Aggressive bool
@@ -44,7 +48,7 @@ func (l *Lefthook) Install(args *InstallArgs) error {
 		return err
 	}
 
-	return l.createHooks(cfg,
+	return l.createHooksIfNeeded(cfg,
 		args.Force || args.Aggressive || l.Options.Force || l.Options.Aggressive)
 }
 
@@ -90,7 +94,7 @@ func (l *Lefthook) createConfig(path string) error {
 	return nil
 }
 
-func (l *Lefthook) createHooks(cfg *config.Config, force bool) error {
+func (l *Lefthook) createHooksIfNeeded(cfg *config.Config, force bool) error {
 	if !force && l.hooksSynchronized() {
 		return nil
 	}
@@ -106,38 +110,33 @@ func (l *Lefthook) createHooks(cfg *config.Config, force bool) error {
 	for hook := range cfg.Hooks {
 		hookNames = append(hookNames, hook)
 
-		err = l.cleanHook(hook, force)
-		if err != nil {
+		if err = l.cleanHook(hook, force); err != nil {
 			return err
 		}
 
-		err = l.addHook(hook, checksum)
-		if err != nil {
+		if err = l.addHook(hook); err != nil {
 			return err
 		}
 	}
 
-	// Add an informational hook to use for checksum comparation.
-	err = l.addHook(config.ChecksumHookName, checksum)
-	if err != nil {
+	if err = l.addHook(config.GhostHookName); err != nil {
+		return nil
+	}
+
+	if err = l.addChecksumFile(checksum); err != nil {
 		return err
 	}
 
-	hookNames = append(hookNames, config.ChecksumHookName)
-	log.Info(log.Cyan("SERVED HOOKS:"), log.Bold(strings.Join(hookNames, ", ")))
+	if len(hookNames) > 0 {
+		log.Info(log.Cyan("SERVED HOOKS:"), log.Bold(strings.Join(hookNames, ", ")))
+	}
 
 	return nil
 }
 
 func (l *Lefthook) hooksSynchronized() bool {
-	checksum, err := l.configChecksum()
-	if err != nil {
-		return false
-	}
-
 	// Check checksum in a checksum file
-	hookFullPath := filepath.Join(l.repo.HooksPath, config.ChecksumHookName)
-	file, err := l.Fs.Open(hookFullPath)
+	file, err := l.Fs.Open(l.checksumFilePath())
 	if err != nil {
 		return false
 	}
@@ -146,14 +145,56 @@ func (l *Lefthook) hooksSynchronized() bool {
 	scanner := bufio.NewScanner(file)
 	scanner.Split(bufio.ScanLines)
 
+	var storedChecksum string
+	var storedTimestamp int64
+
 	for scanner.Scan() {
 		match := lefthookChecksumRegexp.FindStringSubmatch(scanner.Text())
-		if len(match) > 1 && match[1] == checksum {
-			return true
+		if len(match) > 1 {
+			storedChecksum = match[1]
+			storedTimestamp, err = strconv.ParseInt(match[2], timestampBase, timestampBitsize)
+			if err != nil {
+				return false
+			}
+
+			break
 		}
 	}
 
-	return false
+	if len(storedChecksum) == 0 {
+		return false
+	}
+
+	configTimestamp, err := l.configLastUpdateTimestamp()
+	if err != nil {
+		return false
+	}
+
+	if storedTimestamp == configTimestamp {
+		return true
+	}
+
+	configChecksum, err := l.configChecksum()
+	if err != nil {
+		return false
+	}
+
+	return storedChecksum == configChecksum
+}
+
+func (l *Lefthook) configLastUpdateTimestamp() (timestamp int64, err error) {
+	m, err := afero.Glob(l.Fs, filepath.Join(l.repo.RootPath, configGlob))
+	if err != nil {
+		return
+	}
+
+	info, err := l.Fs.Stat(m[0])
+	if err != nil {
+		return
+	}
+
+	timestamp = info.ModTime().Unix()
+	return
 }
 
 func (l *Lefthook) configChecksum() (checksum string, err error) {
@@ -177,3 +218,18 @@ func (l *Lefthook) configChecksum() (checksum string, err error) {
 	checksum = hex.EncodeToString(hash.Sum(nil)[:16])
 	return
 }
+
+func (l *Lefthook) addChecksumFile(checksum string) error {
+	timestamp, err := l.configLastUpdateTimestamp()
+	if err != nil {
+		return err
+	}
+
+	return afero.WriteFile(
+		l.Fs, l.checksumFilePath(), templates.Checksum(checksum, timestamp), checksumFileMode,
+	)
+}
+
+func (l *Lefthook) checksumFilePath() string {
+	return filepath.Join(l.repo.InfoPath, config.ChecksumFileName)
+}