feature: Add support for git lfs (#306)

* feature: Add support for Git LFS

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

* docs: Add notes about Git LFS

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

docs/full_guide.md

@@ -549,6 +549,15 @@ SHA1=$3
 # ...
 ```
 
+## Git LFS support
+
+Lefthook runs LFS hooks internally for the following hooks:
+
+- post-checkout
+- post-commit
+- post-merge
+- pre-push
+
 ## Change directory for script files
 
 You can do this through this config keys:

internal/git/lfs.go

@@ -0,0 +1,35 @@
+package git
+
+import (
+	"os/exec"
+)
+
+const (
+	LFSRequiredFile = ".lfs-required"
+	LFSConfigFile   = ".lfsconfig"
+)
+
+var lfsHooks = [...]string{
+	"post-checkout",
+	"post-commit",
+	"post-merge",
+	"pre-push",
+}
+
+// IsLFSAvailable returns 'true' if git-lfs is installed.
+func IsLFSAvailable() bool {
+	_, err := exec.LookPath("git-lfs")
+
+	return err == nil
+}
+
+// IsLFSHook returns whether the hookName is supported by Git LFS.
+func IsLFSHook(hookName string) bool {
+	for _, lfsHookName := range lfsHooks {
+		if lfsHookName == hookName {
+			return true
+		}
+	}
+
+	return false
+}

internal/lefthook/run.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"path/filepath"
 	"strings"
 	"time"
 
@@ -110,10 +109,8 @@ Run 'lefthook install' manually.`,
 
 	go func() {
 		run.RunAll(
-			[]string{
-				filepath.Join(cfg.SourceDir, hookName),
-				filepath.Join(cfg.SourceDirLocal, hookName),
-			},
+			hookName,
+			[]string{cfg.SourceDir, cfg.SourceDirLocal},
 		)
 		close(resultChan)
 	}()

internal/lefthook/runner/execute_unix.go

@@ -6,6 +6,7 @@ package runner
 import (
 	"bytes"
 	"io"
+	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
@@ -30,3 +31,11 @@ func (e CommandExecutor) Execute(root string, args []string) (*bytes.Buffer, err
 
 	return out, command.Wait()
 }
+
+func (e CommandExecutor) RawExecute(command string, args ...string) error {
+	cmd := exec.Command(command, args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	return cmd.Run()
+}

internal/lefthook/runner/execute_windows.go

@@ -25,3 +25,11 @@ func (e CommandExecutor) Execute(root string, args []string) (*bytes.Buffer, err
 	}
 	return &out, command.Wait()
 }
+
+func (e CommandExecutor) RawExecute(command string, args ...string) error {
+	cmd := exec.Command(command, args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	return cmd.Run()
+}

internal/lefthook/runner/executor.go

@@ -8,4 +8,5 @@ import (
 // It is used here for testing purpose mostly.
 type Executor interface {
 	Execute(root string, args []string) (*bytes.Buffer, error)
+	RawExecute(command string, args ...string) error
 }

internal/lefthook/runner/runner.go

@@ -1,6 +1,7 @@
 package runner
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -50,15 +51,25 @@ func NewRunner(
 	}
 }
 
-func (r *Runner) RunAll(scriptDirs []string) {
+func (r *Runner) RunAll(hookName string, sourceDirs []string) {
+	if err := r.runLFSHook(hookName); err != nil {
+		log.Error(err)
+	}
+
 	log.StartSpinner()
+	defer log.StopSpinner()
+
+	scriptDirs := make([]string, len(sourceDirs))
+	for _, sourceDir := range sourceDirs {
+		scriptDirs = append(scriptDirs, filepath.Join(
+			r.repo.RootPath, sourceDir, hookName,
+		))
+	}
 
 	for _, dir := range scriptDirs {
 		r.runScripts(dir)
 	}
 	r.runCommands()
-
-	log.StopSpinner()
 }
 
 func (r *Runner) fail(name, text string) {
@@ -70,6 +81,51 @@ func (r *Runner) success(name string) {
 	r.resultChan <- resultSuccess(name)
 }
 
+func (r *Runner) runLFSHook(hookName string) error {
+	if !git.IsLFSHook(hookName) {
+		return nil
+	}
+
+	lfsRequiredFile := filepath.Join(r.repo.RootPath, git.LFSRequiredFile)
+	lfsConfigFile := filepath.Join(r.repo.RootPath, git.LFSConfigFile)
+
+	requiredExists, err := afero.Exists(r.repo.Fs, lfsRequiredFile)
+	if err != nil {
+		return err
+	}
+	configExists, err := afero.Exists(r.repo.Fs, lfsConfigFile)
+	if err != nil {
+		return err
+	}
+
+	if git.IsLFSAvailable() {
+		log.Debugf(
+			"Executing LFS Hook: `git lfs %s %s", hookName, strings.Join(r.args, " "),
+		)
+		err := r.exec.RawExecute(
+			"git",
+			append(
+				[]string{"lfs", hookName},
+				r.args...,
+			)...,
+		)
+		if err != nil {
+			return errors.New("git-lfs command failed")
+		}
+	} else if requiredExists || configExists {
+		log.Errorf(
+			"This repository requires Git LFS, but 'git-lfs' wasn't found.\n"+
+				"Install 'git-lfs' or consider reviewing the files:\n"+
+				"  - %s\n"+
+				"  - %s\n",
+			lfsRequiredFile, lfsConfigFile,
+		)
+		return errors.New("git-lfs is required")
+	}
+
+	return nil
+}
+
 func (r *Runner) runScripts(dir string) {
 	files, err := afero.ReadDir(r.fs, dir) // ReadDir already sorts files by .Name()
 	if err != nil || len(files) == 0 {

internal/lefthook/runner/runner_test.go

@@ -27,7 +27,13 @@ func (e TestExecutor) Execute(root string, args []string) (out *bytes.Buffer, er
 	return
 }
 
+func (e TestExecutor) RawExecute(command string, args ...string) error {
+	return nil
+}
+
 func TestRunAll(t *testing.T) {
+	hookName := "pre-commit"
+
 	root, err := filepath.Abs("src")
 	if err != nil {
 		t.Errorf("unexpected error: %s", err)
@@ -44,7 +50,7 @@ func TestRunAll(t *testing.T) {
 	for i, tt := range [...]struct {
 		name          string
 		args          []string
-		scriptDirs    []string
+		sourceDirs    []string
 		existingFiles []string
 		hook          *config.Hook
 		success, fail []Result
@@ -179,13 +185,11 @@ func TestRunAll(t *testing.T) {
 			fail: []Result{{Name: "test", Status: StatusErr, Text: "try 'success'"}},
 		},
 		{
-			name: "with simple scripts",
-			scriptDirs: []string{
-				filepath.Join(root, config.DefaultSourceDir),
-			},
+			name:       "with simple scripts",
+			sourceDirs: []string{config.DefaultSourceDir},
 			existingFiles: []string{
-				filepath.Join(root, config.DefaultSourceDir, "script.sh"),
-				filepath.Join(root, config.DefaultSourceDir, "failing.js"),
+				filepath.Join(root, config.DefaultSourceDir, hookName, "script.sh"),
+				filepath.Join(root, config.DefaultSourceDir, hookName, "failing.js"),
 			},
 			hook: &config.Hook{
 				Commands: map[string]*config.Command{},
@@ -226,7 +230,7 @@ func TestRunAll(t *testing.T) {
 		}
 
 		t.Run(fmt.Sprintf("%d: %s", i, tt.name), func(t *testing.T) {
-			runner.RunAll(tt.scriptDirs)
+			runner.RunAll(hookName, tt.sourceDirs)
 			close(resultChan)
 
 			var success, fail []Result
@@ -238,12 +242,12 @@ func TestRunAll(t *testing.T) {
 				}
 			}
 
-			if !resultsMatch(success, tt.success) {
-				t.Errorf("success results are not matching")
+			if !resultsMatch(tt.success, success) {
+				t.Errorf("success results are not matching\n Need: %v\n Was: %v", tt.success, success)
 			}
 
-			if !resultsMatch(fail, tt.fail) {
-				t.Errorf("fail results are not matching")
+			if !resultsMatch(tt.fail, fail) {
+				t.Errorf("fail results are not matching:\n Need: %v\n Was: %v", tt.fail, fail)
 			}
 		})
 	}