feat: add only option (#478)

docs/configuration.md

@@ -15,6 +15,7 @@
   - [`config`](#config)
 - [Hook](#git-hook)
   - [`skip`](#skip)
+  - [`only`](#only)
   - [`files`](#files-global)
   - [`parallel`](#parallel)
   - [`piped`](#piped)
@@ -25,6 +26,7 @@
 - [Command](#command)
   - [`run`](#run)
   - [`skip`](#skip)
+  - [`only`](#only)
   - [`tags`](#tags)
   - [`glob`](#glob)
   - [`files`](#files)
@@ -37,6 +39,7 @@
 - [Script](#script)
   - [`runner`](#runner)
   - [`skip`](#skip)
+  - [`only`](#only)
   - [`tags`](#tags)
   - [`env`](#env)
   - [`fail_text`](#fail_text)
@@ -718,6 +721,49 @@ pre-commit:
       skip: true
 ```
 
+### `only`
+
+You can force a command, script, or the whole hook to execute only in certain conditions. This option acts like the opposite of [`skip`](#skip). It accepts the same values but skips execution only if the condition is not satisfied.
+
+**Note**
+
+`skip` option takes precedence over `only` option, so if you have conflicting conditions the execution will be skipped.
+
+**Example**
+
+Execute a hook only for `dev/*` branches.
+
+```yml
+# lefthook.yml
+
+pre-commit:
+  only:
+    - ref: dev/*
+  commands:
+    lint:
+      run: yarn lint
+    test:
+      run: yarn test
+```
+
+When rebasing execute quick linter but skip usual linter and tests.
+
+```yml
+# lefthook.yml
+
+pre-commit:
+  commands:
+    lint:
+      skip: rebase
+      run: yarn lint
+    test:
+      skip: rebase
+      run: yarn test
+    lint-on-rebase:
+      only: rebase
+      run: yarn lint-quickly
+```
+
 ### `tags`
 
 You can specify tags for commands and scripts. This is useful for [excluding](#exclude_tags). You can specify more than one tag using comma or space.

internal/config/command.go

@@ -15,6 +15,7 @@ type Command struct {
 	Run string `mapstructure:"run"`
 
 	Skip  interface{}       `mapstructure:"skip"`
+	Only  interface{}       `mapstructure:"only"`
 	Tags  []string          `mapstructure:"tags"`
 	Glob  string            `mapstructure:"glob"`
 	Files string            `mapstructure:"files"`
@@ -37,10 +38,7 @@ func (c Command) Validate() error {
 }
 
 func (c Command) DoSkip(gitState git.State) bool {
-	if value := c.Skip; value != nil {
-		return isSkip(gitState, value)
-	}
-	return false
+	return doSkip(gitState, c.Skip, c.Only)
 }
 
 type commandRunReplace struct {

internal/config/hook.go

@@ -30,6 +30,7 @@ type Hook struct {
 	Piped       bool        `mapstructure:"piped"`
 	ExcludeTags []string    `mapstructure:"exclude_tags"`
 	Skip        interface{} `mapstructure:"skip"`
+	Only        interface{} `mapstructure:"only"`
 	Follow      bool        `mapstructure:"follow"`
 }
 
@@ -42,10 +43,7 @@ func (h *Hook) Validate() error {
 }
 
 func (h *Hook) DoSkip(gitState git.State) bool {
-	if value := h.Skip; value != nil {
-		return isSkip(gitState, value)
-	}
-	return false
+	return doSkip(gitState, h.Skip, h.Only)
 }
 
 func unmarshalHooks(base, extra *viper.Viper) (*Hook, error) {

internal/config/load_test.go

@@ -97,7 +97,7 @@ pre-commit:
       run: docker exec -it ruby:2.7 {cmd}
   scripts:
     "format.sh":
-      skip: true
+      only: true
 
 pre-push:
   commands:
@@ -128,7 +128,7 @@ pre-push:
 						},
 						Scripts: map[string]*Script{
 							"format.sh": {
-								Skip:   true,
+								Only:   true,
 								Runner: "bash",
 							},
 						},
@@ -265,7 +265,7 @@ remote:
   config: examples/custom.yml
 
 pre-commit:
-  skip:
+  only:
     - ref: main
   commands:
     global:
@@ -277,11 +277,14 @@ pre-commit:
 pre-commit:
   commands:
     lint:
-      run: yarn lint
-      skip:
+      only:
         - merge
+        - rebase
+      run: yarn lint
   scripts:
     "test.sh":
+      skip:
+        - merge
       runner: bash
 `,
 			remoteConfigPath: filepath.Join(root, ".git", "info", "lefthook-remotes", "lefthook", "examples", "custom.yml"),
@@ -296,11 +299,11 @@ pre-commit:
 				},
 				Hooks: map[string]*Hook{
 					"pre-commit": {
-						Skip: []interface{}{map[string]interface{}{"ref": "main"}},
+						Only: []interface{}{map[string]interface{}{"ref": "main"}},
 						Commands: map[string]*Command{
 							"lint": {
 								Run:  "yarn lint",
-								Skip: []interface{}{"merge"},
+								Only: []interface{}{"merge", "rebase"},
 							},
 							"global": {
 								Run: "echo 'Global!'",
@@ -309,6 +312,7 @@ pre-commit:
 						Scripts: map[string]*Script{
 							"test.sh": {
 								Runner: "bash",
+								Skip:   []interface{}{"merge"},
 							},
 						},
 					},

internal/config/script.go

@@ -13,6 +13,7 @@ type Script struct {
 	Runner string `mapstructure:"runner"`
 
 	Skip interface{}       `mapstructure:"skip"`
+	Only interface{}       `mapstructure:"only"`
 	Tags []string          `mapstructure:"tags"`
 	Env  map[string]string `mapstructure:"env"`
 
@@ -22,10 +23,7 @@ type Script struct {
 }
 
 func (s Script) DoSkip(gitState git.State) bool {
-	if value := s.Skip; value != nil {
-		return isSkip(gitState, value)
-	}
-	return false
+	return doSkip(gitState, s.Skip, s.Only)
 }
 
 type scriptRunnerReplace struct {

internal/config/skip.go

@@ -6,7 +6,21 @@ import (
 	"github.com/evilmartians/lefthook/internal/git"
 )
 
-func isSkip(gitState git.State, value interface{}) bool {
+func doSkip(gitState git.State, skip, only interface{}) bool {
+	if skip != nil {
+		if matches(gitState, skip) {
+			return true
+		}
+	}
+
+	if only != nil {
+		return !matches(gitState, only)
+	}
+
+	return false
+}
+
+func matches(gitState git.State, value interface{}) bool {
 	switch typedValue := value.(type) {
 	case bool:
 		return typedValue

internal/config/skip_test.go

@@ -6,76 +6,114 @@ import (
 	"github.com/evilmartians/lefthook/internal/git"
 )
 
-func TestIsSkip(t *testing.T) {
+func TestDoSkip(t *testing.T) {
 	for _, tt := range [...]struct {
-		name    string
-		skip    interface{}
-		state   git.State
-		skipped bool
+		name       string
+		state      git.State
+		skip, only interface{}
+		skipped    bool
 	}{
 		{
 			name:    "when true",
-			skip:    true,
 			state:   git.State{},
+			skip:    true,
 			skipped: true,
 		},
 		{
 			name:    "when false",
-			skip:    false,
 			state:   git.State{},
+			skip:    false,
 			skipped: false,
 		},
 		{
 			name:    "when merge",
-			skip:    "merge",
 			state:   git.State{Step: "merge"},
+			skip:    "merge",
 			skipped: true,
 		},
 		{
 			name:    "when rebase (but want merge)",
-			skip:    "merge",
 			state:   git.State{Step: "rebase"},
+			skip:    "merge",
 			skipped: false,
 		},
 		{
 			name:    "when rebase",
-			skip:    []interface{}{"rebase"},
 			state:   git.State{Step: "rebase"},
+			skip:    []interface{}{"rebase"},
 			skipped: true,
 		},
 		{
 			name:    "when rebase (but want merge)",
-			skip:    []interface{}{"merge"},
 			state:   git.State{Step: "rebase"},
+			skip:    []interface{}{"merge"},
 			skipped: false,
 		},
 		{
 			name:    "when branch",
-			skip:    []interface{}{map[string]interface{}{"ref": "feat/skipme"}},
 			state:   git.State{Branch: "feat/skipme"},
+			skip:    []interface{}{map[string]interface{}{"ref": "feat/skipme"}},
 			skipped: true,
 		},
 		{
 			name:    "when branch doesn't match",
-			skip:    []interface{}{map[string]interface{}{"ref": "feat/skipme"}},
 			state:   git.State{Branch: "feat/important"},
+			skip:    []interface{}{map[string]interface{}{"ref": "feat/skipme"}},
 			skipped: false,
 		},
 		{
 			name:    "when branch glob",
-			skip:    []interface{}{map[string]interface{}{"ref": "feat/*"}},
 			state:   git.State{Branch: "feat/important"},
+			skip:    []interface{}{map[string]interface{}{"ref": "feat/*"}},
 			skipped: true,
 		},
 		{
 			name:    "when branch glob doesn't match",
+			state:   git.State{Branch: "feat"},
 			skip:    []interface{}{map[string]interface{}{"ref": "feat/*"}},
+			skipped: false,
+		},
+		{
+			name:    "when only specified",
 			state:   git.State{Branch: "feat"},
+			only:    []interface{}{map[string]interface{}{"ref": "feat"}},
 			skipped: false,
 		},
+		{
+			name:    "when only branch doesn't match",
+			state:   git.State{Branch: "dev"},
+			only:    []interface{}{map[string]interface{}{"ref": "feat"}},
+			skipped: true,
+		},
+		{
+			name:    "when only branch with glob",
+			state:   git.State{Branch: "feat/important"},
+			only:    []interface{}{map[string]interface{}{"ref": "feat/*"}},
+			skipped: false,
+		},
+		{
+			name:    "when only merge",
+			state:   git.State{Step: "merge"},
+			only:    []interface{}{"merge"},
+			skipped: false,
+		},
+		{
+			name:    "when only and skip",
+			state:   git.State{Step: "rebase"},
+			skip:    []interface{}{map[string]interface{}{"ref": "feat/*"}},
+			only:    "rebase",
+			skipped: false,
+		},
+		{
+			name:    "when only and skip applies skip",
+			state:   git.State{Step: "rebase"},
+			skip:    []interface{}{"rebase"},
+			only:    "rebase",
+			skipped: true,
+		},
 	} {
 		t.Run(tt.name, func(t *testing.T) {
-			if isSkip(tt.state, tt.skip) != tt.skipped {
+			if doSkip(tt.state, tt.skip, tt.only) != tt.skipped {
 				t.Errorf("Expected: %v, Was %v", tt.skipped, !tt.skipped)
 			}
 		})

internal/lefthook/runner/prepare_command.go

@@ -17,7 +17,7 @@ type commandArgs struct {
 }
 
 func (r *Runner) prepareCommand(name string, command *config.Command) (*commandArgs, error) {
-	if command.Skip != nil && command.DoSkip(r.Repo.State()) {
+	if command.DoSkip(r.Repo.State()) {
 		return nil, errors.New("settings")
 	}
 

internal/lefthook/runner/prepare_script.go

@@ -10,7 +10,7 @@ import (
 )
 
 func (r *Runner) prepareScript(script *config.Script, path string, file os.FileInfo) ([]string, error) {
-	if script.Skip != nil && script.DoSkip(r.Repo.State()) {
+	if script.DoSkip(r.Repo.State()) {
 		return nil, errors.New("settings")
 	}
 

internal/lefthook/runner/runner.go

@@ -63,7 +63,7 @@ func (r *Runner) RunAll(sourceDirs []string) {
 		log.Error(err)
 	}
 
-	if r.Hook.Skip != nil && r.Hook.DoSkip(r.Repo.State()) {
+	if r.Hook.DoSkip(r.Repo.State()) {
 		r.logSkip(r.HookName, "hook setting")
 		return
 	}