Merge pull request #1361 from urfave/dearchap-remove_reflect

Remove reflect calls for doc generation (#1259)

flag.go

@@ -117,6 +117,12 @@ type DocGenerationFlag interface {
 	// GetValue returns the flags value as string representation and an empty
 	// string if the flag takes no value at all.
 	GetValue() string
+
+	// GetDefaultText returns the default text for this flag
+	GetDefaultText() string
+
+	// GetEnvVars returns the env vars for this flag
+	GetEnvVars() []string
 }
 
 // VisibleFlag is an interface that allows to check if a flag is visible
@@ -299,55 +305,29 @@ func formatDefault(format string) string {
 }
 
 func stringifyFlag(f Flag) string {
-	fv := flagValue(f)
+	// enforce DocGeneration interface on flags to avoid reflection
-
+	df, ok := f.(DocGenerationFlag)
-	switch f := f.(type) {
+	if !ok {
-	case *IntSliceFlag:
+		return ""
-		return withEnvHint(flagStringSliceField(f, "EnvVars"),
-			stringifyIntSliceFlag(f))
-	case *Int64SliceFlag:
-		return withEnvHint(flagStringSliceField(f, "EnvVars"),
-			stringifyInt64SliceFlag(f))
-	case *Float64SliceFlag:
-		return withEnvHint(flagStringSliceField(f, "EnvVars"),
-			stringifyFloat64SliceFlag(f))
-	case *StringSliceFlag:
-		return withEnvHint(flagStringSliceField(f, "EnvVars"),
-			stringifyStringSliceFlag(f))
 	}
 
-	placeholder, usage := unquoteUsage(fv.FieldByName("Usage").String())
+	placeholder, usage := unquoteUsage(df.GetUsage())
-
+	needsPlaceholder := df.TakesValue()
-	needsPlaceholder := false
-	defaultValueString := ""
-	val := fv.FieldByName("Value")
-	if val.IsValid() {
-		needsPlaceholder = val.Kind() != reflect.Bool
-		defaultValueString = fmt.Sprintf(formatDefault("%v"), val.Interface())
-
-		if val.Kind() == reflect.String && val.String() != "" {
-			defaultValueString = fmt.Sprintf(formatDefault("%q"), val.String())
-		}
-	}
-
-	helpText := fv.FieldByName("DefaultText")
-	if helpText.IsValid() && helpText.String() != "" {
-		needsPlaceholder = val.Kind() != reflect.Bool
-		defaultValueString = fmt.Sprintf(formatDefault("%s"), helpText.String())
-	}
-
-	if defaultValueString == formatDefault("") {
-		defaultValueString = ""
-	}
 
 	if needsPlaceholder && placeholder == "" {
 		placeholder = defaultPlaceholder
 	}
 
+	defaultValueString := ""
+
+	if s := df.GetDefaultText(); s != "" {
+		defaultValueString = fmt.Sprintf(formatDefault("%s"), s)
+	}
+
 	usageWithDefault := strings.TrimSpace(usage + defaultValueString)
 
-	return withEnvHint(flagStringSliceField(f, "EnvVars"),
+	return withEnvHint(df.GetEnvVars(),
-		fmt.Sprintf("%s\t%s", prefixedNames(f.Names(), placeholder), usageWithDefault))
+		fmt.Sprintf("%s\t%s", prefixedNames(df.Names(), placeholder), usageWithDefault))
 }
 
 func stringifyIntSliceFlag(f *IntSliceFlag) string {

flag_bool.go

@@ -63,6 +63,19 @@ func (f *BoolFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *BoolFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return fmt.Sprintf("%v", f.Value)
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *BoolFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *BoolFlag) Apply(set *flag.FlagSet) error {
 	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {

flag_duration.go

@@ -63,6 +63,19 @@ func (f *DurationFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *DurationFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *DurationFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *DurationFlag) Apply(set *flag.FlagSet) error {
 	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {

flag_float64.go

@@ -55,7 +55,20 @@ func (f *Float64Flag) GetUsage() string {
 // GetValue returns the flags value as string representation and an empty
 // string if the flag takes no value at all.
 func (f *Float64Flag) GetValue() string {
-	return fmt.Sprintf("%f", f.Value)
+	return fmt.Sprintf("%v", f.Value)
+}
+
+// GetDefaultText returns the default text for this flag
+func (f *Float64Flag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *Float64Flag) GetEnvVars() []string {
+	return f.EnvVars
 }
 
 // IsVisible returns true if the flag is not hidden, otherwise false

flag_float64_slice.go

@@ -95,7 +95,7 @@ func (f *Float64SliceFlag) IsSet() bool {
 // String returns a readable representation of this value
 // (for usage defaults)
 func (f *Float64SliceFlag) String() string {
-	return FlagStringer(f)
+	return withEnvHint(f.GetEnvVars(), stringifyFloat64SliceFlag(f))
 }
 
 // Names returns the names of the flag
@@ -132,6 +132,19 @@ func (f *Float64SliceFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *Float64SliceFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *Float64SliceFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *Float64SliceFlag) Apply(set *flag.FlagSet) error {
 	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {

flag_generic.go

@@ -71,6 +71,19 @@ func (f *GenericFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *GenericFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *GenericFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply takes the flagset and calls Set on the generic flag with the value
 // provided by the user for parsing by the flag
 func (f GenericFlag) Apply(set *flag.FlagSet) error {

flag_int.go

@@ -63,6 +63,19 @@ func (f *IntFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *IntFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *IntFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *IntFlag) Apply(set *flag.FlagSet) error {
 	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {

flag_int64.go

@@ -63,6 +63,19 @@ func (f *Int64Flag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *Int64Flag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *Int64Flag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *Int64Flag) Apply(set *flag.FlagSet) error {
 	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {

flag_int64_slice.go

@@ -96,7 +96,7 @@ func (f *Int64SliceFlag) IsSet() bool {
 // String returns a readable representation of this value
 // (for usage defaults)
 func (f *Int64SliceFlag) String() string {
-	return FlagStringer(f)
+	return withEnvHint(f.GetEnvVars(), stringifyInt64SliceFlag(f))
 }
 
 // Names returns the names of the flag
@@ -133,6 +133,19 @@ func (f *Int64SliceFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *Int64SliceFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *Int64SliceFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *Int64SliceFlag) Apply(set *flag.FlagSet) error {
 	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {

flag_int_slice.go

@@ -107,7 +107,7 @@ func (f *IntSliceFlag) IsSet() bool {
 // String returns a readable representation of this value
 // (for usage defaults)
 func (f *IntSliceFlag) String() string {
-	return FlagStringer(f)
+	return withEnvHint(f.GetEnvVars(), stringifyIntSliceFlag(f))
 }
 
 // Names returns the names of the flag
@@ -144,6 +144,19 @@ func (f *IntSliceFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *IntSliceFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *IntSliceFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *IntSliceFlag) Apply(set *flag.FlagSet) error {
 	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {

flag_path.go

@@ -1,6 +1,9 @@
 package cli
 
-import "flag"
+import (
+	"flag"
+	"fmt"
+)
 
 type PathFlag struct {
 	Name        string
@@ -59,6 +62,22 @@ func (f *PathFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *PathFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	if f.Value == "" {
+		return f.Value
+	}
+	return fmt.Sprintf("%q", f.Value)
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *PathFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *PathFlag) Apply(set *flag.FlagSet) error {
 	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {

flag_string.go

@@ -1,6 +1,9 @@
 package cli
 
-import "flag"
+import (
+	"flag"
+	"fmt"
+)
 
 // StringFlag is a flag with type string
 type StringFlag struct {
@@ -60,6 +63,22 @@ func (f *StringFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *StringFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	if f.Value == "" {
+		return f.Value
+	}
+	return fmt.Sprintf("%q", f.Value)
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *StringFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *StringFlag) Apply(set *flag.FlagSet) error {
 	if val, ok := flagFromEnvOrFile(f.EnvVars, f.FilePath); ok {

flag_string_slice.go

@@ -92,7 +92,7 @@ func (f *StringSliceFlag) IsSet() bool {
 // String returns a readable representation of this value
 // (for usage defaults)
 func (f *StringSliceFlag) String() string {
-	return FlagStringer(f)
+	return withEnvHint(f.GetEnvVars(), stringifyStringSliceFlag(f))
 }
 
 // Names returns the names of the flag
@@ -129,6 +129,19 @@ func (f *StringSliceFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *StringSliceFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *StringSliceFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *StringSliceFlag) Apply(set *flag.FlagSet) error {
 

flag_test.go

@@ -132,8 +132,13 @@ func TestFlagsFromEnv(t *testing.T) {
 	for i, test := range flagTests {
 		defer resetEnv(os.Environ())
 		os.Clearenv()
-		envVarSlice := reflect.Indirect(reflect.ValueOf(test.flag)).FieldByName("EnvVars").Slice(0, 1)
+
-		_ = os.Setenv(envVarSlice.Index(0).String(), test.input)
+		f, ok := test.flag.(DocGenerationFlag)
+		if !ok {
+			t.Errorf("flag %v needs to implement DocGenerationFlag to retrieve env vars", test.flag)
+		}
+		envVarSlice := f.GetEnvVars()
+		_ = os.Setenv(envVarSlice[0], test.input)
 
 		a := App{
 			Flags: []Flag{test.flag},
@@ -163,6 +168,183 @@ func TestFlagsFromEnv(t *testing.T) {
 	}
 }
 
+type nodocFlag struct {
+	Flag
+
+	Name string
+}
+
+func TestFlagStringifying(t *testing.T) {
+	for _, tc := range []struct {
+		name     string
+		fl       Flag
+		expected string
+	}{
+		{
+			name:     "bool-flag",
+			fl:       &BoolFlag{Name: "vividly"},
+			expected: "--vividly\t(default: false)",
+		},
+		{
+			name:     "bool-flag-with-default-text",
+			fl:       &BoolFlag{Name: "wildly", DefaultText: "scrambled"},
+			expected: "--wildly\t(default: scrambled)",
+		},
+		{
+			name:     "duration-flag",
+			fl:       &DurationFlag{Name: "scream-for"},
+			expected: "--scream-for value\t(default: 0s)",
+		},
+		{
+			name:     "duration-flag-with-default-text",
+			fl:       &DurationFlag{Name: "feels-about", DefaultText: "whimsically"},
+			expected: "--feels-about value\t(default: whimsically)",
+		},
+		{
+			name:     "float64-flag",
+			fl:       &Float64Flag{Name: "arduous"},
+			expected: "--arduous value\t(default: 0)",
+		},
+		{
+			name:     "float64-flag-with-default-text",
+			fl:       &Float64Flag{Name: "filibuster", DefaultText: "42"},
+			expected: "--filibuster value\t(default: 42)",
+		},
+		{
+			name:     "float64-slice-flag",
+			fl:       &Float64SliceFlag{Name: "pizzas"},
+			expected: "--pizzas value\t",
+		},
+		{
+			name:     "float64-slice-flag-with-default-text",
+			fl:       &Float64SliceFlag{Name: "pepperonis", DefaultText: "shaved"},
+			expected: "--pepperonis value\t(default: shaved)",
+		},
+		{
+			name:     "generic-flag",
+			fl:       &GenericFlag{Name: "yogurt"},
+			expected: "--yogurt value\t",
+		},
+		{
+			name:     "generic-flag-with-default-text",
+			fl:       &GenericFlag{Name: "ricotta", DefaultText: "plops"},
+			expected: "--ricotta value\t(default: plops)",
+		},
+		{
+			name:     "int-flag",
+			fl:       &IntFlag{Name: "grubs"},
+			expected: "--grubs value\t(default: 0)",
+		},
+		{
+			name:     "int-flag-with-default-text",
+			fl:       &IntFlag{Name: "poisons", DefaultText: "11ty"},
+			expected: "--poisons value\t(default: 11ty)",
+		},
+		{
+			name:     "int-slice-flag",
+			fl:       &IntSliceFlag{Name: "pencils"},
+			expected: "--pencils value\t",
+		},
+		{
+			name:     "int-slice-flag-with-default-text",
+			fl:       &IntFlag{Name: "pens", DefaultText: "-19"},
+			expected: "--pens value\t(default: -19)",
+		},
+		{
+			name:     "int64-flag",
+			fl:       &Int64Flag{Name: "flume"},
+			expected: "--flume value\t(default: 0)",
+		},
+		{
+			name:     "int64-flag-with-default-text",
+			fl:       &Int64Flag{Name: "shattering", DefaultText: "22"},
+			expected: "--shattering value\t(default: 22)",
+		},
+		{
+			name:     "int64-slice-flag",
+			fl:       &Int64SliceFlag{Name: "drawers"},
+			expected: "--drawers value\t",
+		},
+		{
+			name:     "int64-slice-flag-with-default-text",
+			fl:       &Int64SliceFlag{Name: "handles", DefaultText: "-2"},
+			expected: "--handles value\t(default: -2)",
+		},
+		{
+			name:     "path-flag",
+			fl:       &PathFlag{Name: "soup"},
+			expected: "--soup value\t",
+		},
+		{
+			name:     "path-flag-with-default-text",
+			fl:       &PathFlag{Name: "stew", DefaultText: "charred/beans"},
+			expected: "--stew value\t(default: charred/beans)",
+		},
+		{
+			name:     "string-flag",
+			fl:       &StringFlag{Name: "arf-sound"},
+			expected: "--arf-sound value\t",
+		},
+		{
+			name:     "string-flag-with-default-text",
+			fl:       &StringFlag{Name: "woof-sound", DefaultText: "urp"},
+			expected: "--woof-sound value\t(default: urp)",
+		},
+		{
+			name:     "string-slice-flag",
+			fl:       &StringSliceFlag{Name: "meow-sounds"},
+			expected: "--meow-sounds value\t",
+		},
+		{
+			name:     "string-slice-flag-with-default-text",
+			fl:       &StringSliceFlag{Name: "moo-sounds", DefaultText: "awoo"},
+			expected: "--moo-sounds value\t(default: awoo)",
+		},
+		{
+			name:     "timestamp-flag",
+			fl:       &TimestampFlag{Name: "eating"},
+			expected: "--eating value\t",
+		},
+		{
+			name:     "timestamp-flag-with-default-text",
+			fl:       &TimestampFlag{Name: "sleeping", DefaultText: "earlier"},
+			expected: "--sleeping value\t(default: earlier)",
+		},
+		{
+			name:     "uint-flag",
+			fl:       &UintFlag{Name: "jars"},
+			expected: "--jars value\t(default: 0)",
+		},
+		{
+			name:     "uint-flag-with-default-text",
+			fl:       &UintFlag{Name: "bottles", DefaultText: "99"},
+			expected: "--bottles value\t(default: 99)",
+		},
+		{
+			name:     "uint64-flag",
+			fl:       &Uint64Flag{Name: "cans"},
+			expected: "--cans value\t(default: 0)",
+		},
+		{
+			name:     "uint64-flag-with-default-text",
+			fl:       &UintFlag{Name: "tubes", DefaultText: "13"},
+			expected: "--tubes value\t(default: 13)",
+		},
+		{
+			name:     "nodoc-flag",
+			fl:       &nodocFlag{Name: "scarecrow"},
+			expected: "",
+		},
+	} {
+		t.Run(tc.name, func(ct *testing.T) {
+			s := stringifyFlag(tc.fl)
+			if s != tc.expected {
+				ct.Errorf("stringified flag %q does not match expected %q", s, tc.expected)
+			}
+		})
+	}
+}
+
 var stringFlagTests = []struct {
 	name     string
 	aliases  []string

flag_timestamp.go

@@ -119,6 +119,19 @@ func (f *TimestampFlag) IsVisible() bool {
 	return !f.Hidden
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *TimestampFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *TimestampFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Apply populates the flag given the flag set and environment
 func (f *TimestampFlag) Apply(set *flag.FlagSet) error {
 	if f.Layout == "" {

flag_uint.go

@@ -88,6 +88,19 @@ func (f *UintFlag) GetValue() string {
 	return fmt.Sprintf("%d", f.Value)
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *UintFlag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *UintFlag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Uint looks up the value of a local UintFlag, returns
 // 0 if not found
 func (c *Context) Uint(name string) uint {

flag_uint64.go

@@ -88,6 +88,19 @@ func (f *Uint64Flag) GetValue() string {
 	return fmt.Sprintf("%d", f.Value)
 }
 
+// GetDefaultText returns the default text for this flag
+func (f *Uint64Flag) GetDefaultText() string {
+	if f.DefaultText != "" {
+		return f.DefaultText
+	}
+	return f.GetValue()
+}
+
+// GetEnvVars returns the env vars for this flag
+func (f *Uint64Flag) GetEnvVars() []string {
+	return f.EnvVars
+}
+
 // Uint64 looks up the value of a local Uint64Flag, returns
 // 0 if not found
 func (c *Context) Uint64(name string) uint64 {

internal/build/build.go

@@ -193,7 +193,7 @@ func checkBinarySizeActionFunc(c *cli.Context) (err error) {
 		cliBuiltFilePath     = "./internal/example-cli/built-example"
 		helloSourceFilePath  = "./internal/example-hello-world/example-hello-world.go"
 		helloBuiltFilePath   = "./internal/example-hello-world/built-example"
-		desiredMinBinarySize = 1.9
+		desiredMinBinarySize = 1.675
 		desiredMaxBinarySize = 2.2
 		badNewsEmoji         = "🚨"
 		goodNewsEmoji        = "✨"