Add count option for bool flags

cmd/urfave-cli-genflags/generated.gotmpl

@@ -23,7 +23,7 @@ type {{.TypeName}} struct {
   EnvVars []string
 
   {{range .StructFields}}
-  {{.Name}} {{.Type}}
+  {{.Name}} {{if .Pointer}}*{{end}}{{.Type}}
   {{end}}
 }
 

cmd/urfave-cli-genflags/main.go

@@ -230,8 +230,9 @@ type FlagTypeConfig struct {
 }
 
 type FlagStructField struct {
-	Name string
-	Type string
+	Name    string
+	Type    string
+	Pointer bool
 }
 
 type FlagType struct {

context.go

@@ -105,6 +105,16 @@ func (cCtx *Context) Lineage() []*Context {
 	return lineage
 }
 
+// Count returns the num of occurences of this flag
+func (cCtx *Context) Count(name string) int {
+	if fs := cCtx.lookupFlagSet(name); fs != nil {
+		if cf, ok := fs.Lookup(name).Value.(Countable); ok {
+			return cf.Count()
+		}
+	}
+	return 0
+}
+
 // Value returns the value of the flag corresponding to `name`
 func (cCtx *Context) Value(name string) interface{} {
 	if fs := cCtx.lookupFlagSet(name); fs != nil {

docs/v2/examples/flags.md

@@ -101,6 +101,46 @@ func main() {
 
 See full list of flags at https://pkg.go.dev/github.com/urfave/cli/v2
 
+For bool flags you can specify the flag multiple times to get a count(e.g -v -v -v or -vvv)
+
+<!-- {
+  "args": ["&#45;&#45;foo", "&#45;&#45;foo"],
+  "output": "count 2"
+} -->
+```go
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/urfave/cli/v2"
+)
+
+func main() {
+	var count int
+
+	app := &cli.App{
+		Flags: []cli.Flag{
+			&cli.BoolFlag{
+				Name:        "foo",
+				Usage:       "foo greeting",
+				Count: &count,
+			},
+		},
+		Action: func(cCtx *cli.Context) error {
+			fmt.Println("count", count)
+			return nil
+		},
+	}
+
+	if err := app.Run(os.Args); err != nil {
+		log.Fatal(err)
+	}
+}
+```
+
 #### Placeholder Values
 
 Sometimes it's useful to specify a flag's value within the usage string itself.

flag-spec.yaml

@@ -3,7 +3,9 @@
 # `Spec` type that maps to this file structure.
 
 flag_types:
-  bool: {}
+  bool: 
+    struct_fields:
+      - { name: Count, type: int, pointer: true }
   float64: {}
   int64:
     struct_fields:

flag.go

@@ -139,6 +139,12 @@ type CategorizableFlag interface {
 	GetCategory() string
 }
 
+// Countable is an interface to enable detection of flag values which support
+// repetitive flags
+type Countable interface {
+	Count() int
+}
+
 func flagSet(name string, flags []Flag) (*flag.FlagSet, error) {
 	set := flag.NewFlagSet(name, flag.ContinueOnError)
 

flag_bool.go

@@ -1,11 +1,63 @@
 package cli
 
 import (
+	"errors"
 	"flag"
 	"fmt"
 	"strconv"
 )
 
+// boolValue needs to implement the boolFlag internal interface in flag
+// to be able to capture bool fields and values
+//
+//	type boolFlag interface {
+//		  Value
+//		  IsBoolFlag() bool
+//	}
+type boolValue struct {
+	destination *bool
+	count       *int
+}
+
+func newBoolValue(val bool, p *bool, count *int) *boolValue {
+	*p = val
+	return &boolValue{
+		destination: p,
+		count:       count,
+	}
+}
+
+func (b *boolValue) Set(s string) error {
+	v, err := strconv.ParseBool(s)
+	if err != nil {
+		err = errors.New("parse error")
+		return err
+	}
+	*b.destination = v
+	if b.count != nil {
+		*b.count = *b.count + 1
+	}
+	return err
+}
+
+func (b *boolValue) Get() interface{} { return *b.destination }
+
+func (b *boolValue) String() string {
+	if b.destination != nil {
+		return strconv.FormatBool(*b.destination)
+	}
+	return strconv.FormatBool(false)
+}
+
+func (b *boolValue) IsBoolFlag() bool { return true }
+
+func (b *boolValue) Count() int {
+	if b.count != nil {
+		return *b.count
+	}
+	return 0
+}
+
 // TakesValue returns true of the flag takes a value, otherwise false
 func (f *BoolFlag) TakesValue() bool {
 	return false
@@ -60,12 +112,19 @@ func (f *BoolFlag) Apply(set *flag.FlagSet) error {
 		f.HasBeenSet = true
 	}
 
+	count := f.Count
+	dest := f.Destination
+
+	if count == nil {
+		count = new(int)
+	}
+	if dest == nil {
+		dest = new(bool)
+	}
+
 	for _, name := range f.Names() {
-		if f.Destination != nil {
-			set.BoolVar(f.Destination, name, f.Value, f.Usage)
-			continue
-		}
-		set.Bool(name, f.Value, f.Usage)
+		value := newBoolValue(f.Value, dest, count)
+		set.Var(value, name, f.Usage)
 	}
 
 	return nil

flag_test.go

@@ -62,6 +62,53 @@ func TestBoolFlagValueFromContext(t *testing.T) {
 	expect(t, ff.Get(ctx), false)
 }
 
+func TestBoolFlagApply_SetsCount(t *testing.T) {
+	v := false
+	count := 0
+	fl := BoolFlag{Name: "wat", Aliases: []string{"W", "huh"}, Destination: &v, Count: &count}
+	set := flag.NewFlagSet("test", 0)
+	err := fl.Apply(set)
+	expect(t, err, nil)
+
+	err = set.Parse([]string{"--wat", "-W", "--huh"})
+	expect(t, err, nil)
+	expect(t, v, true)
+	expect(t, count, 3)
+}
+
+func TestBoolFlagCountFromContext(t *testing.T) {
+
+	boolCountTests := []struct {
+		input         []string
+		expectedVal   bool
+		expectedCount int
+	}{
+		{
+			input:         []string{"-tf", "-w", "-huh"},
+			expectedVal:   true,
+			expectedCount: 3,
+		},
+		{
+			input:         []string{},
+			expectedVal:   false,
+			expectedCount: 0,
+		},
+	}
+
+	for _, bct := range boolCountTests {
+		set := flag.NewFlagSet("test", 0)
+		ctx := NewContext(nil, set, nil)
+		tf := &BoolFlag{Name: "tf", Aliases: []string{"w", "huh"}}
+		err := tf.Apply(set)
+		expect(t, err, nil)
+
+		err = set.Parse(bct.input)
+		expect(t, err, nil)
+		expect(t, tf.Get(ctx), bct.expectedVal)
+		expect(t, ctx.Count("tf"), bct.expectedCount)
+	}
+}
+
 func TestFlagsFromEnv(t *testing.T) {
 	newSetFloat64Slice := func(defaults ...float64) Float64Slice {
 		s := NewFloat64Slice(defaults...)

godoc-current.txt

@@ -49,8 +49,8 @@ AUTHOR{{with $length := len .Authors}}{{if ne 1 $length}}S{{end}}{{end}}:
 
 COMMANDS:{{range .VisibleCategories}}{{if .Name}}
    {{.Name}}:{{range .VisibleCommands}}
-     {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{else}}{{range .VisibleCommands}}
-   {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{end}}{{end}}{{end}}{{if .VisibleFlagCategories}}
+     {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{else}}{{ $cv := offsetCommands .VisibleCommands 5}}{{range .VisibleCommands}}
+   {{$s := join .Names ", "}}{{$s}}{{ $sp := subtract $cv (offset $s 3) }}{{ indent $sp ""}}{{wrap .Usage $cv}}{{end}}{{end}}{{end}}{{end}}{{if .VisibleFlagCategories}}
 
 GLOBAL OPTIONS:{{range .VisibleFlagCategories}}
    {{if .Name}}{{.Name}}
@@ -157,8 +157,8 @@ DESCRIPTION:
 
 COMMANDS:{{range .VisibleCategories}}{{if .Name}}
    {{.Name}}:{{range .VisibleCommands}}
-     {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{else}}{{range .VisibleCommands}}
-   {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{end}}{{end}}{{if .VisibleFlags}}
+     {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{else}}{{ $cv := offsetCommands .VisibleCommands 5}}{{range .VisibleCommands}}
+     {{$s := join .Names ", "}}{{$s}}{{ $sp := subtract $cv (offset $s 3) }}{{ indent $sp ""}}{{wrap .Usage $cv}}{{end}}{{end}}{{end}}{{if .VisibleFlags}}
 
 OPTIONS:
    {{range .VisibleFlags}}{{.}}
@@ -300,6 +300,8 @@ type App struct {
 	CommandNotFound CommandNotFoundFunc
 	// Execute this function if a usage error occurs
 	OnUsageError OnUsageErrorFunc
+	// Execute this function when an invalid flag is accessed from the context
+	InvalidFlagAccessHandler InvalidFlagAccessFunc
 	// Compilation date
 	Compiled time.Time
 	// List of all authors who contributed
@@ -450,6 +452,8 @@ type BoolFlag struct {
 
 	Aliases []string
 	EnvVars []string
+
+	Count *int
 }
     BoolFlag is a flag with type bool
 
@@ -629,6 +633,9 @@ func (cCtx *Context) Args() Args
 func (cCtx *Context) Bool(name string) bool
     Bool looks up the value of a local BoolFlag, returns false if not found
 
+func (cCtx *Context) Count(name string) int
+    Count returns the num of occurences of this flag
+
 func (cCtx *Context) Duration(name string) time.Duration
     Duration looks up the value of a local DurationFlag, returns 0 if not found
 
@@ -701,6 +708,12 @@ func (cCtx *Context) Uint64(name string) uint64
 func (cCtx *Context) Value(name string) interface{}
     Value returns the value of the flag corresponding to `name`
 
+type Countable interface {
+	Count() int
+}
+    Countable is an interface to enable detection of flag values which support
+    repetitive flags
+
 type DocGenerationFlag interface {
 	Flag
 
@@ -1420,6 +1433,10 @@ func (f *IntSliceFlag) String() string
 func (f *IntSliceFlag) TakesValue() bool
     TakesValue returns true of the flag takes a value, otherwise false
 
+type InvalidFlagAccessFunc func(*Context, string)
+    InvalidFlagAccessFunc is executed when an invalid flag is accessed from the
+    context.
+
 type MultiError interface {
 	error
 	Errors() []error

zz_generated.flags.go

@@ -327,6 +327,8 @@ type BoolFlag struct {
 
 	Aliases []string
 	EnvVars []string
+
+	Count *int
 }
 
 // String returns a readable representation of this value (for usage defaults)