feat: add prek support as pre-commit alternative (#1040)

prek (https://prek.j178.dev) is a faster Rust-based alternative to
pre-commit that uses the same .pre-commit-config.yaml config files.

Changes:
- Add prek detection pattern in hookManagerPatterns (before pre-commit
  to ensure correct detection since prek hooks may contain 'pre-commit')
- Handle prek in checkManagerBdIntegration using same config parser
- Update init_git_hooks.go to recognize prek-installed hooks
- Rename isPreCommit field to isPreCommitFramework for clarity
- Use regex pattern matching all pre-commit/prek signatures consistently
- Add test cases for prek run and prek hook-impl signatures

Co-authored-by: Ismar Iljazovic <ismar@gmail.com>

cmd/bd/doctor/fix/hooks.go

@@ -27,6 +27,8 @@ type hookManagerConfig struct {
 
 // hookManagerConfigs defines external hook managers in priority order.
 // See https://lefthook.dev/configuration/ for lefthook config options.
+// Note: prek (https://prek.j178.dev) uses the same config files as pre-commit
+// but is a faster Rust-based alternative. We detect both from the same config.
 var hookManagerConfigs = []hookManagerConfig{
 	{"lefthook", []string{
 		// YAML variants
@@ -38,6 +40,7 @@ var hookManagerConfigs = []hookManagerConfig{
 		"lefthook.json", ".lefthook.json", ".config/lefthook.json",
 	}},
 	{"husky", []string{".husky"}},
+	// pre-commit and prek share the same config files; we detect which is active from git hooks
 	{"pre-commit", []string{".pre-commit-config.yaml", ".pre-commit-config.yml"}},
 	{"overcommit", []string{".overcommit.yml"}},
 	{"yorkie", []string{".yorkie"}},
@@ -92,9 +95,12 @@ type hookManagerPattern struct {
 }
 
 // hookManagerPatterns identifies which hook manager installed a git hook (in priority order).
+// Note: prek must come before pre-commit since prek hooks may also contain "pre-commit" in paths.
 var hookManagerPatterns = []hookManagerPattern{
 	{"lefthook", regexp.MustCompile(`(?i)lefthook`)},
 	{"husky", regexp.MustCompile(`(?i)(\.husky|husky\.sh)`)},
+	// prek (https://prek.j178.dev) - faster Rust-based pre-commit alternative
+	{"prek", regexp.MustCompile(`(?i)(prek\s+run|prek\s+hook-impl)`)},
 	{"pre-commit", regexp.MustCompile(`(?i)(pre-commit\s+run|\.pre-commit-config|INSTALL_PYTHON|PRE_COMMIT)`)},
 	{"simple-git-hooks", regexp.MustCompile(`(?i)simple-git-hooks`)},
 }
@@ -470,8 +476,13 @@ func checkManagerBdIntegration(name, path string) *HookIntegrationStatus {
 		return CheckLefthookBdIntegration(path)
 	case "husky":
 		return CheckHuskyBdIntegration(path)
-	case "pre-commit":
+	case "pre-commit", "prek":
-		return CheckPrecommitBdIntegration(path)
+		// prek uses the same config format as pre-commit
+		status := CheckPrecommitBdIntegration(path)
+		if status != nil {
+			status.Manager = name // Use the actual detected manager name
+		}
+		return status
 	default:
 		return nil
 	}

cmd/bd/doctor/fix/hooks_test.go

@@ -586,6 +586,16 @@ func TestDetectActiveHookManager(t *testing.T) {
 			hookContent: "#!/usr/bin/env bash\n# PRE_COMMIT hook\npre-commit run --all-files\n",
 			expected:    "pre-commit",
 		},
+		{
+			name:        "prek run signature",
+			hookContent: "#!/bin/sh\nprek run pre-commit\n",
+			expected:    "prek",
+		},
+		{
+			name:        "prek hook-impl signature",
+			hookContent: "#!/usr/bin/env bash\nexec prek hook-impl --hook-type=pre-commit\n",
+			expected:    "prek",
+		},
 		{
 			name:        "simple-git-hooks signature",
 			hookContent: "#!/bin/sh\n# simple-git-hooks\nnpm run lint\n",

cmd/bd/init_git_hooks.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"regexp"
 	"strings"
 	"time"
 
@@ -12,6 +13,11 @@ import (
 	"github.com/steveyegge/beads/internal/ui"
 )
 
+// preCommitFrameworkPattern matches pre-commit or prek framework hooks.
+// Uses same patterns as hookManagerPatterns in doctor/fix/hooks.go for consistency.
+// Includes all detection patterns: pre-commit run, prek run/hook-impl, config file refs, and pre-commit env vars.
+var preCommitFrameworkPattern = regexp.MustCompile(`(?i)(pre-commit\s+run|prek\s+run|prek\s+hook-impl|\.pre-commit-config|INSTALL_PYTHON|PRE_COMMIT)`)
+
 // hooksInstalled checks if bd git hooks are installed
 func hooksInstalled() bool {
 	gitDir, err := git.GetGitDir()
@@ -68,7 +74,7 @@ type hookInfo struct {
 	path                 string
 	exists               bool
 	isBdHook             bool
-	isPreCommit bool
+	isPreCommitFramework bool // true for pre-commit or prek
 	content              string
 }
 
@@ -91,10 +97,10 @@ func detectExistingHooks() []hookInfo {
 			hooks[i].exists = true
 			hooks[i].content = string(content)
 			hooks[i].isBdHook = strings.Contains(hooks[i].content, "bd (beads)")
-			// Only detect pre-commit framework if not a bd hook
+			// Only detect pre-commit/prek framework if not a bd hook
+			// Use regex for consistency with DetectActiveHookManager patterns
 			if !hooks[i].isBdHook {
-				hooks[i].isPreCommit = strings.Contains(hooks[i].content, "pre-commit run") ||
+				hooks[i].isPreCommitFramework = preCommitFrameworkPattern.MatchString(hooks[i].content)
-					strings.Contains(hooks[i].content, ".pre-commit-config")
 			}
 		}
 	}
@@ -108,8 +114,8 @@ func promptHookAction(existingHooks []hookInfo) string {
 	for _, hook := range existingHooks {
 		if hook.exists && !hook.isBdHook {
 			hookType := "custom script"
-			if hook.isPreCommit {
+			if hook.isPreCommitFramework {
-				hookType = "pre-commit framework"
+				hookType = "pre-commit/prek framework"
 			}
 			fmt.Printf("  - %s (%s)\n", hook.name, hookType)
 		}

cmd/bd/init_hooks_test.go

@@ -29,7 +29,7 @@ func TestDetectExistingHooks(t *testing.T) {
 			hookContent              string
 			wantExists               bool
 			wantIsBdHook             bool
-			wantIsPreCommit bool
+			wantIsPreCommitFramework bool
 		}{
 			{
 				name:       "no hook",
@@ -48,7 +48,7 @@ func TestDetectExistingHooks(t *testing.T) {
 				setupHook:                "pre-commit",
 				hookContent:              "#!/bin/sh\n# pre-commit framework\npre-commit run",
 				wantExists:               true,
-				wantIsPreCommit: true,
+				wantIsPreCommitFramework: true,
 			},
 			{
 				name:        "custom hook",
@@ -90,8 +90,8 @@ func TestDetectExistingHooks(t *testing.T) {
 				if found.isBdHook != tt.wantIsBdHook {
 					t.Errorf("isBdHook = %v, want %v", found.isBdHook, tt.wantIsBdHook)
 				}
-				if found.isPreCommit != tt.wantIsPreCommit {
+				if found.isPreCommitFramework != tt.wantIsPreCommitFramework {
-					t.Errorf("isPreCommit = %v, want %v", found.isPreCommit, tt.wantIsPreCommit)
+					t.Errorf("isPreCommitFramework = %v, want %v", found.isPreCommitFramework, tt.wantIsPreCommitFramework)
 				}
 			})
 		}