Added CTL package

.VERSION

@@ -1 +1 @@
-v0.1
+v0.2

ctl/bool.go

@@ -0,0 +1,54 @@
+package ctl
+
+import (
+	"reflect"
+	"strings"
+
+	"github.com/alecthomas/kong"
+	"github.com/pkg/errors"
+)
+
+type boolPtrMapper struct{}
+
+func (boolPtrMapper) Decode(ctx *kong.DecodeContext, target reflect.Value) error {
+	trueVal := true
+	falseVal := false
+
+	truePtr := &trueVal
+	falsePtr := &falseVal
+
+	peekType := ctx.Scan.Peek().Type
+	if peekType == kong.FlagValueToken {
+		token := ctx.Scan.Pop()
+		switch v := token.Value.(type) {
+		case string:
+			v = strings.ToLower(v)
+			switch v {
+			case "true", "1", "yes":
+				target.Set(reflect.ValueOf(truePtr))
+
+			case "false", "0", "no":
+				target.Set(reflect.ValueOf(falsePtr))
+
+			default:
+				return errors.Errorf("bool value must be true, 1, yes, false, 0 or no but got %q", v)
+			}
+
+		case bool:
+			target.Set(reflect.ValueOf(&v))
+
+		default:
+			return errors.Errorf("expected bool but got %q (%T)", token.Value, token.Value)
+		}
+	} else {
+		target.Set(reflect.ValueOf(truePtr))
+	}
+	return nil
+}
+
+func (boolPtrMapper) IsBool() bool { return true }
+
+var b bool
+
+// BoolPtrMapper is an option to register a mapper to *bool type flag
+var BoolPtrMapper = kong.TypeMapper(reflect.TypeOf(&b), boolPtrMapper{})

ctl/ctl.go

@@ -0,0 +1,24 @@
+package ctl
+
+import (
+	"fmt"
+
+	"github.com/alecthomas/kong"
+	"github.com/effective-security/x/slices"
+)
+
+// VersionFlag is a flag to print version
+type VersionFlag string
+
+// Decode the flag
+func (v VersionFlag) Decode(_ *kong.DecodeContext) error { return nil }
+
+// IsBool returns true for the flag
+func (v VersionFlag) IsBool() bool { return true }
+
+// BeforeApply is executed before context is applied
+func (v VersionFlag) BeforeApply(app *kong.Kong, vars kong.Vars) error {
+	fmt.Fprintln(app.Stdout, slices.StringsCoalesce(vars["version"], string(v)))
+	app.Exit(0)
+	return nil
+}

ctl/ctl_test.go

@@ -0,0 +1,91 @@
+package ctl
+
+import (
+	"testing"
+
+	"github.com/alecthomas/kong"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestVersionVal(t *testing.T) {
+	v := VersionFlag("1.2.3")
+	assert.True(t, v.IsBool())
+	assert.NoError(t, v.Decode(nil))
+}
+
+func TestBool(t *testing.T) {
+	var bm boolPtrMapper
+	assert.True(t, bm.IsBool())
+}
+
+func TestParse(t *testing.T) {
+	var cl struct {
+		Version VersionFlag
+		Cmd     struct {
+			Ptr *bool `help:"test bool ptr"`
+		} `kong:"cmd"`
+	}
+
+	p := mustNew(t, &cl)
+	ctx, err := p.Parse([]string{"cmd", "--ptr=false"})
+	require.NoError(t, err)
+	require.Equal(t, "cmd", ctx.Command())
+	if assert.NotNil(t, cl.Cmd.Ptr) {
+		assert.False(t, *cl.Cmd.Ptr)
+	}
+
+	ctx, err = p.Parse([]string{"cmd", "--ptr=1"})
+	require.NoError(t, err)
+	require.Equal(t, "cmd", ctx.Command())
+	if assert.NotNil(t, cl.Cmd.Ptr) {
+		assert.True(t, *cl.Cmd.Ptr)
+	}
+
+	ctx, err = p.Parse([]string{"cmd", "--ptr"})
+	require.NoError(t, err)
+	require.Equal(t, "cmd", ctx.Command())
+	if assert.NotNil(t, cl.Cmd.Ptr) {
+		assert.True(t, *cl.Cmd.Ptr)
+	}
+
+	_, err = p.Parse([]string{"cmd", "--ptr=invalid"})
+	assert.EqualError(t, err, "--ptr: bool value must be true, 1, yes, false, 0 or no but got \"invalid\"")
+}
+
+func TestVersionFlag(t *testing.T) {
+	var cl struct {
+		Version VersionFlag
+	}
+	cl.Version = "1.2.3"
+
+	options := []kong.Option{
+		kong.Name("test"),
+		kong.Exit(func(int) {
+			t.Helper()
+
+		}),
+		BoolPtrMapper,
+	}
+	parser, err := kong.New(&cl, options...)
+	require.NoError(t, err)
+
+	_, err = parser.Parse([]string{"--version"})
+	require.NoError(t, err)
+}
+
+func mustNew(t *testing.T, cli interface{}, options ...kong.Option) *kong.Kong {
+	t.Helper()
+	options = append([]kong.Option{
+		kong.Name("test"),
+		kong.Exit(func(int) {
+			t.Helper()
+			t.Fatalf("unexpected exit()")
+		}),
+		BoolPtrMapper,
+	}, options...)
+	parser, err := kong.New(cli, options...)
+	require.NoError(t, err)
+
+	return parser
+}

go.mod

@@ -3,6 +3,7 @@ module github.com/effective-security/x
 go 1.21
 
 require (
+	github.com/alecthomas/kong v0.8.1
 	github.com/deckarep/golang-set v1.8.0
 	github.com/effective-security/xlog v0.6.0
 	github.com/oleiade/reflections v1.0.1

go.sum

@@ -1,5 +1,11 @@
 github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/alecthomas/assert/v2 v2.1.0 h1:tbredtNcQnoSd3QBhQWI7QZ3XHOVkw1Moklp2ojoH/0=
+github.com/alecthomas/assert/v2 v2.1.0/go.mod h1:b/+1DI2Q6NckYi+3mXyH3wFb8qG37K/DuK80n7WefXA=
+github.com/alecthomas/kong v0.8.1 h1:acZdn3m4lLRobeh3Zi2S2EpnXTd1mOL6U7xVml+vfkY=
+github.com/alecthomas/kong v0.8.1/go.mod h1:n1iCIO2xS46oE8ZfYCNDqdR0b0wZNrXAIAqro/2132U=
+github.com/alecthomas/repr v0.1.0 h1:ENn2e1+J3k09gyj2shc0dHr/yjaWSHRlrJ4DPMevDqE=
+github.com/alecthomas/repr v0.1.0/go.mod h1:2kn6fqh/zIyPLmm3ugklbEi5hg5wS435eygvNfaDQL8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -8,6 +14,8 @@ github.com/deckarep/golang-set v1.8.0/go.mod h1:5nI87KwE7wgsBU1F4GKAw2Qod7p5kyS3
 github.com/effective-security/xlog v0.6.0 h1:n1MzotZSHZ1+XMO3CQcc7xEO8y+0BMbNEHA0SsTLs/8=
 github.com/effective-security/xlog v0.6.0/go.mod h1:ZDG9qha5Mt18D5DNd/8WhHXzw3f9JeOUVcXHYvWu3/U=
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
+github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
+github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=