feat: add validate command

.gitignore

@@ -2,7 +2,6 @@
 .idea/
 /lefthook
 /lefthook-local.yml
-/gen_schema
 
 tmp/
 dist/

cmd/commands.go

@@ -20,4 +20,5 @@ var commands = [...]command{
 	run{},
 	dump{},
 	selfUpdate{},
+	validate{},
 }

cmd/commands_no_self_update.go

@@ -19,4 +19,5 @@ var commands = [...]command{
 	uninstall{},
 	run{},
 	dump{},
+	validate{},
 }

cmd/validate.go

@@ -0,0 +1,24 @@
+package cmd
+
+import (
+	_ "embed"
+
+	"github.com/spf13/cobra"
+
+	"github.com/evilmartians/lefthook/internal/lefthook"
+)
+
+type validate struct{}
+
+func (validate) New(opts *lefthook.Options) *cobra.Command {
+	return &cobra.Command{
+		Use:     "validate",
+		Short:   "Validate lefthook config",
+		Long:    addDoc,
+		Example: "lefthook validate",
+		Args:    cobra.NoArgs,
+		RunE: func(_cmd *cobra.Command, _args []string) error {
+			return lefthook.Validate(opts)
+		},
+	}
+}

go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/creack/pty v1.1.24
 	github.com/gobwas/glob v0.2.3
 	github.com/invopop/jsonschema v0.13.0
+	github.com/kaptinlin/jsonschema v0.2.2
 	github.com/knadh/koanf/maps v0.1.1
 	github.com/knadh/koanf/parsers/json v0.1.0
 	github.com/knadh/koanf/parsers/toml/v2 v2.1.0
@@ -23,7 +24,6 @@ require (
 	github.com/schollz/progressbar/v3 v3.17.1
 	github.com/spf13/afero v1.11.0
 	github.com/spf13/cobra v1.8.1
-	github.com/stoewer/go-strcase v1.3.0
 	github.com/stretchr/testify v1.9.0
 )
 
@@ -34,6 +34,11 @@ require (
 	github.com/charmbracelet/x/ansi v0.4.2 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/go-viper/mapstructure/v2 v2.1.0 // indirect
+	github.com/goccy/go-json v0.10.3 // indirect
+	github.com/goccy/go-yaml v1.13.4 // indirect
+	github.com/gotnospirit/makeplural v0.0.0-20180622080156-a5f48d94d976 // indirect
+	github.com/gotnospirit/messageformat v0.0.0-20221001023931-dfe49f1eb092 // indirect
+	github.com/kaptinlin/go-i18n v0.1.3 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db // indirect
@@ -47,7 +52,7 @@ require (
 
 require (
 	github.com/alessio/shellescape v1.4.1
-	github.com/fatih/color v1.14.1 // indirect
+	github.com/fatih/color v1.18.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
@@ -59,6 +64,6 @@ require (
 	github.com/spf13/pflag v1.0.5 // indirect
 	golang.org/x/sys v0.27.0 // indirect
 	golang.org/x/term v0.26.0 // indirect
-	golang.org/x/text v0.14.0 // indirect
+	golang.org/x/text v0.19.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1
 )

go.sum

@@ -20,21 +20,41 @@ github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46t
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/creack/pty v1.1.24 h1:bJrF4RRfyJnbTJqzRLHzcGaZK1NeM5kTC9jGgovnR1s=
 github.com/creack/pty v1.1.24/go.mod h1:08sCNb52WyoAwi2QDyzUCTgcvVFhUzewun7wtTfvcwE=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/fatih/color v1.14.1 h1:qfhVLaG5s+nCROl1zJsZRxFeYrHLqWroPOQ8BWiNb4w=
-github.com/fatih/color v1.14.1/go.mod h1:2oHN61fhTpgcxD3TSWCgKDiH1+x4OiDVVGH8WlgGZGg=
+github.com/fatih/color v1.18.0 h1:S8gINlzdQ840/4pfAwic/ZE0djQEH3wM94VfqLTZcOM=
+github.com/fatih/color v1.18.0/go.mod h1:4FelSpRwEGDpQ12mAdzqdOukCy4u8WUtOY6lkT/6HfU=
+github.com/gabriel-vasile/mimetype v1.4.3 h1:in2uUcidCuFcDKtdcBxlR0rJ1+fsokWf+uqxgUFjbI0=
+github.com/gabriel-vasile/mimetype v1.4.3/go.mod h1:d8uq/6HKRL6CGdk+aubisF/M5GcPfT7nKyLpA0lbSSk=
+github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/oXslEjJA=
+github.com/go-playground/locales v0.14.1/go.mod h1:hxrqLVvrK65+Rwrd5Fc6F2O76J/NuW9t0sjnWqG1slY=
+github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJnYK9S473LQFuzCbDbfSFY=
+github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY=
+github.com/go-playground/validator/v10 v10.22.1 h1:40JcKH+bBNGFczGuoBYgX4I6m/i27HYW8P9FDk5PbgA=
+github.com/go-playground/validator/v10 v10.22.1/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
 github.com/go-viper/mapstructure/v2 v2.1.0 h1:gHnMa2Y/pIxElCH2GlZZ1lZSsn6XMtufpGyP1XxdC/w=
 github.com/go-viper/mapstructure/v2 v2.1.0/go.mod h1:oJDH3BJKyqBA2TXFhDsKDGDTlndYOZ6rGS0BRZIxGhM=
 github.com/gobwas/glob v0.2.3 h1:A4xDbljILXROh+kObIiy5kIaPYD8e96x1tgBhUI5J+Y=
 github.com/gobwas/glob v0.2.3/go.mod h1:d3Ez4x06l9bZtSvzIay5+Yzi0fmZzPgnTbPcKjJAkT8=
+github.com/goccy/go-json v0.10.3 h1:KZ5WoDbxAIgm2HNbYckL0se1fHD6rz5j4ywS6ebzDqA=
+github.com/goccy/go-json v0.10.3/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
+github.com/goccy/go-yaml v1.13.4 h1:XOnLX9GqT+kH/gB7YzCMUiDBFU9B7pm3HZz6kyeDPkk=
+github.com/goccy/go-yaml v1.13.4/go.mod h1:IjYwxUiJDoqpx2RmbdjMUceGHZwYLon3sfOGl5Hi9lc=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/gotnospirit/makeplural v0.0.0-20180622080156-a5f48d94d976 h1:b70jEaX2iaJSPZULSUxKtm73LBfsCrMsIlYCUgNGSIs=
+github.com/gotnospirit/makeplural v0.0.0-20180622080156-a5f48d94d976/go.mod h1:ZGQeOwybjD8lkCjIyJfqR5LD2wMVHJ31d6GdPxoTsWY=
+github.com/gotnospirit/messageformat v0.0.0-20221001023931-dfe49f1eb092 h1:c7gcNWTSr1gtLp6PyYi3wzvFCEcHJ4YRobDgqmIgf7Q=
+github.com/gotnospirit/messageformat v0.0.0-20221001023931-dfe49f1eb092/go.mod h1:ZZAN4fkkful3l1lpJwF8JbW41ZiG9TwJ2ZlqzQovBNU=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/invopop/jsonschema v0.13.0 h1:KvpoAJWEjR3uD9Kbm2HWJmqsEaHt8lBUpd0qHcIi21E=
 github.com/invopop/jsonschema v0.13.0/go.mod h1:ffZ5Km5SWWRAIN6wbDXItl95euhFz2uON45H2qjYt+0=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
+github.com/kaptinlin/go-i18n v0.1.3 h1:Zmc2sp3N3eNxAPEiyfdbZgF+QF8LZdOdZNR1gHefUe4=
+github.com/kaptinlin/go-i18n v0.1.3/go.mod h1:giU+qqtzFZ2U0ksKKVuSxtIFzBLkMA/vlKTeJDyyM2c=
+github.com/kaptinlin/jsonschema v0.2.2 h1:aspDbCaqAJ/GSnzmtaSesC0+lnTOjLRamFB/k8mo60s=
+github.com/kaptinlin/jsonschema v0.2.2/go.mod h1:HkWM5Yd1hA7K5nvRx/A67wQw/khr6b0/DHrP5CWgAbY=
 github.com/knadh/koanf/maps v0.1.1 h1:G5TjmUh2D7G2YWf5SQQqSiHRJEjaicvU0KpypqB3NIs=
 github.com/knadh/koanf/maps v0.1.1/go.mod h1:npD/QZY3V6ghQDdcQzl1W4ICNVTkohC8E73eI2xW4yI=
 github.com/knadh/koanf/parsers/json v0.1.0 h1:dzSZl5pf5bBcW0Acnu20Djleto19T0CfHcvZ14NJ6fU=
@@ -51,6 +71,8 @@ github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ=
+github.com/leodido/go-urn v1.4.0/go.mod h1:bvxc+MVxLKB4z00jd1z+Dvzr47oO32F/QSNjSBOlFxI=
 github.com/lucasb-eyer/go-colorful v1.2.0 h1:1nnpGOrhyZZuNyfu1QjKiUICQ74+3FNCN69Aj6K7nkY=
 github.com/lucasb-eyer/go-colorful v1.2.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=
@@ -77,7 +99,6 @@ github.com/muesli/termenv v0.15.2/go.mod h1:Epx+iuz8sNs7mNKhxzH4fWXGNpZwUaJKRS1n
 github.com/pelletier/go-toml/v2 v2.2.3 h1:YmeHyLY8mFWbdkNWwpr+qIL2bEqT0o95WSdkNHvL12M=
 github.com/pelletier/go-toml/v2 v2.2.3/go.mod h1:MfCQTFTvCcUyyvvwm1+G6H/jORL20Xlb6rzQu9GuUkc=
 github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
@@ -95,31 +116,28 @@ github.com/spf13/cobra v1.8.1 h1:e5/vxKd/rZsfSJMUX1agtjeTDf+qv1/JdBF8gg5k9ZM=
 github.com/spf13/cobra v1.8.1/go.mod h1:wHxEcudfqmLYa8iTfL+OuZPbBZkmvliBWKIezN3kD9Y=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
-github.com/stoewer/go-strcase v1.3.0 h1:g0eASXYtp+yvN9fK8sH94oCIk0fau9uV1/ZdJ0AVEzs=
-github.com/stoewer/go-strcase v1.3.0/go.mod h1:fAH5hQ5pehh+j3nZfvwdk2RgEgQjAoM8wodgtPmh1xo=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
-github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
-github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/test-go/testify v1.1.4 h1:Tf9lntrKUMHiXQ07qBScBTSA0dhYQlu83hswqelv1iE=
+github.com/test-go/testify v1.1.4/go.mod h1:rH7cfJo/47vWGdi4GPj16x3/t1xGOj2YxzmNQzk2ghU=
 github.com/wk8/go-ordered-map/v2 v2.1.8 h1:5h/BUHu93oj4gIdvHHHGsScSTMijfx5PeYkE/fJgbpc=
 github.com/wk8/go-ordered-map/v2 v2.1.8/go.mod h1:5nJHM5DyteebpVlHnWMV0rPz6Zp7+xBAnxjb1X5vnTw=
+golang.org/x/crypto v0.28.0 h1:GBDwsMXVQi34v5CCYUm2jkJvu4cbtru2U4TN2PSyQnw=
+golang.org/x/crypto v0.28.0/go.mod h1:rmgy+3RHxRZMyY0jjAJShp2zgEdOqj2AO7U0pYmeQ7U=
+golang.org/x/net v0.30.0 h1:AcW1SDZMkb8IpzCdQUaIq2sP4sZ4zw+55h6ynffypl4=
+golang.org/x/net v0.30.0/go.mod h1:2wGyMJ5iFasEhkwi13ChkO/t1ECNC4X4eBKkVFyYFlU=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.27.0 h1:wBqf8DvsY9Y/2P8gAfPDEYNuS30J4lPHJxXSb/nJZ+s=
 golang.org/x/sys v0.27.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.26.0 h1:WEQa6V3Gja/BhNxg540hBip/kkaYtRg3cxg4oXSw4AU=
 golang.org/x/term v0.26.0/go.mod h1:Si5m1o57C5nBNQo5z1iq+XDijt21BDBDp2bK0QI8e3E=
-golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
-golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
+golang.org/x/text v0.19.0 h1:kTxAhCbGbxhK0IwgSKiMO5awPoDQ0RpfiVYBfK860YM=
+golang.org/x/text v0.19.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
 golang.org/x/tools v0.22.0 h1:gqSGLZqv+AI9lIQzniJ0nZDRG5GBPsSi+DRNHWNz6yA=
 golang.org/x/tools v0.22.0/go.mod h1:aCwcsjqvq7Yqt6TNyX7QMU2enbQ/Gt0bo6krSeEri+c=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/config/command.go

@@ -10,10 +10,10 @@ type Command struct {
 	Run   string `json:"run"             mapstructure:"run"   toml:"run"             yaml:"run"`
 	Files string `json:"files,omitempty" mapstructure:"files" toml:"files,omitempty" yaml:",omitempty"`
 
-	Skip interface{}       `json:"skip,omitempty" jsonschema:"oneof_type=boolean;array" mapstructure:"skip"   toml:"skip,omitempty,inline" yaml:",omitempty"`
-	Only interface{}       `json:"only,omitempty" jsonschema:"oneof_type=boolean;array" mapstructure:"only"   toml:"only,omitempty,inline" yaml:",omitempty"`
-	Tags []string          `json:"tags,omitempty" mapstructure:"tags"                   toml:"tags,omitempty" yaml:",omitempty"`
-	Env  map[string]string `json:"env,omitempty"  mapstructure:"env"                    toml:"env,omitempty"  yaml:",omitempty"`
+	Skip interface{}       `json:"skip,omitempty" jsonschema:"oneof_type=boolean;array" mapstructure:"skip"  toml:"skip,omitempty,inline" yaml:",omitempty"`
+	Only interface{}       `json:"only,omitempty" jsonschema:"oneof_type=boolean;array" mapstructure:"only"  toml:"only,omitempty,inline" yaml:",omitempty"`
+	Tags []string          `json:"tags,omitempty" jsonschema:"oneof_type=string;array"  mapstructure:"tags"  toml:"tags,omitempty"        yaml:",omitempty"`
+	Env  map[string]string `json:"env,omitempty"  mapstructure:"env"                    toml:"env,omitempty" yaml:",omitempty"`
 
 	FileTypes []string `json:"file_types,omitempty" koanf:"file_types" mapstructure:"file_types" toml:"file_types,omitempty" yaml:"file_types,omitempty"`
 

internal/config/load.go

@@ -76,26 +76,25 @@ func loadOne(k *koanf.Koanf, filesystem afero.Fs, root string, names []string) e
 	return ConfigNotFoundError{fmt.Sprintf("No config files with names %q have been found in \"%s\"", names, root)}
 }
 
-// Loads configs from the given directory with extensions.
-func Load(filesystem afero.Fs, repo *git.Repository) (*Config, error) {
+func LoadKoanf(filesystem afero.Fs, repo *git.Repository) (*koanf.Koanf, *koanf.Koanf, error) {
 	main := koanf.New(".")
 
 	// Load main (e.g. lefthook.yml)
 	if err := loadOne(main, filesystem, repo.RootPath, mainConfigNames); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	// Save `extends` and `remotes`
 	extends := main.Strings("extends")
 	var remotes []*Remote
 	if err := main.Unmarshal("remotes", &remotes); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	// Deprecated
 	var remote *Remote
 	if err := main.Unmarshal("remote", &remote); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	// Backward compatibility for `remote`. Will be deleted in future major release
@@ -107,20 +106,20 @@ func Load(filesystem afero.Fs, repo *git.Repository) (*Config, error) {
 
 	// Load main `extends`
 	if err := extend(secondary, filesystem, repo.RootPath, extends); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	// Load main `remotes`
 	if err := loadRemotes(secondary, filesystem, repo, remotes); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 
 	// Load optional local config (e.g. lefthook-local.yml)
 	var noLocal bool
 	if err := loadOne(secondary, filesystem, repo.RootPath, localConfigNames); err != nil {
 		var configNotFoundErr ConfigNotFoundError
 		if ok := errors.As(err, &configNotFoundErr); !ok {
-			return nil, err
+			return nil, nil, err
 		}
 		noLocal = true
 	}
@@ -129,10 +128,20 @@ func Load(filesystem afero.Fs, repo *git.Repository) (*Config, error) {
 	localExtends := secondary.Strings("extends")
 	if !noLocal && !slices.Equal(extends, localExtends) {
 		if err := extend(secondary, filesystem, repo.RootPath, localExtends); err != nil {
-			return nil, err
+			return nil, nil, err
 		}
 	}
 
+	return main, secondary, nil
+}
+
+// Loads configs from the given directory with extensions.
+func Load(filesystem afero.Fs, repo *git.Repository) (*Config, error) {
+	main, secondary, err := LoadKoanf(filesystem, repo)
+	if err != nil {
+		return nil, err
+	}
+
 	var config Config
 
 	config.SourceDir = DefaultSourceDir

internal/config/script.go

@@ -10,7 +10,7 @@ type Script struct {
 
 	Skip     interface{}       `json:"skip,omitempty"     jsonschema:"oneof_type=boolean;array" mapstructure:"skip"       toml:"skip,omitempty,inline" yaml:",omitempty"`
 	Only     interface{}       `json:"only,omitempty"     jsonschema:"oneof_type=boolean;array" mapstructure:"only"       toml:"only,omitempty,inline" yaml:",omitempty"`
-	Tags     []string          `json:"tags,omitempty"     mapstructure:"tags"                   toml:"tags,omitempty"     yaml:",omitempty"`
+	Tags     []string          `json:"tags,omitempty"     jsonschema:"oneof_type=string;array"  mapstructure:"tags"       toml:"tags,omitempty"        yaml:",omitempty"`
 	Env      map[string]string `json:"env,omitempty"      mapstructure:"env"                    toml:"env,omitempty"      yaml:",omitempty"`
 	Priority int               `json:"priority,omitempty" mapstructure:"priority"               toml:"priority,omitempty" yaml:",omitempty"`
 

internal/lefthook/validate.go

@@ -0,0 +1,91 @@
+package lefthook
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/kaptinlin/jsonschema"
+
+	"github.com/evilmartians/lefthook/internal/config"
+	"github.com/evilmartians/lefthook/internal/log"
+)
+
+const schemaUrl = "https://raw.githubusercontent.com/evilmartians/lefthook/master/schema.json"
+
+func Validate(opts *Options) error {
+	lefthook, err := initialize(opts)
+	if err != nil {
+		return fmt.Errorf("couldn't initialize lefthook: %w", err)
+	}
+
+	main, secondary, err := config.LoadKoanf(lefthook.Fs, lefthook.repo)
+	if err != nil {
+		return err
+	}
+
+	compiler := jsonschema.NewCompiler()
+
+	schema, err := compiler.GetSchema(schemaUrl)
+	if err != nil {
+		return err
+	}
+
+	result := schema.Validate(main.Raw())
+	if !result.IsValid() {
+		details := result.ToList()
+		logValidationErrors(0, *details)
+
+		return errors.New("Validation failed for main config")
+	}
+
+	result = schema.Validate(secondary.Raw())
+	if !result.IsValid() {
+		details := result.ToList()
+		logValidationErrors(0, *details)
+
+		return errors.New("Validation failed for secondary config")
+	}
+
+	log.Info("All good")
+	return nil
+}
+
+func logValidationErrors(indent int, details jsonschema.List) {
+	if details.Valid {
+		return
+	}
+
+	if len(details.InstanceLocation) > 0 {
+		logDetail(indent, details)
+
+		indent += 2
+	}
+
+	for _, d := range details.Details {
+		logValidationErrors(indent, d)
+	}
+}
+
+func logDetail(indent int, details jsonschema.List) {
+	var errors []string
+	if len(details.Errors) > 0 {
+		for _, err := range details.Errors {
+			errors = append(errors, err)
+		}
+	}
+
+	option := strings.Repeat(" ", indent) + strings.TrimLeft(details.InstanceLocation, "/") + ":"
+
+	if len(errors) == 0 {
+		option = log.Gray(option)
+	} else {
+		option = log.Yellow(option)
+	}
+
+	if len(details.Details) > 0 {
+		log.Info(option)
+	} else {
+		log.Info(option, log.Red(strings.Join(errors, ",")))
+	}
+}