Merge branch 'v2' into v2-completion

.travis.yml

@@ -7,11 +7,11 @@ cache:
   - node_modules
 
 go:
-- 1.2.2
+- 1.2.x
-- 1.3.3
+- 1.3.x
-- 1.4
+- 1.4.2
-- 1.5.4
+- 1.5.x
-- 1.6.2
+- 1.6.x
 - master
 
 env: pip_install="pip install --user"
@@ -20,17 +20,12 @@ matrix:
   allow_failures:
   - go: master
   include:
-  - go: 1.6.2
+  - go: 1.6.x
     os: osx
     env: pip_install="sudo pip install"
 
 before_script:
 - $pip_install flake8
-- go get github.com/urfave/gfmrun/...
-- go get golang.org/x/tools/cmd/goimports || true
-- if [ ! -f node_modules/.bin/markdown-toc ] ; then
-    npm install markdown-toc ;
-  fi
 - mkdir -p ${GOPATH%%:*}/src/gopkg.in/urfave
 - rm -rvf ${GOPATH%%:*}/src/gopkg.in/urfave/cli.v2
 - rm -rvf ${GOPATH%%:*}/pkg/*/gopkg.in/urfave/cli.v2.a
@@ -38,10 +33,4 @@ before_script:
 
 script:
 - flake8 runtests cli-v1-to-v2 generate-flag-types
-- ./runtests gen
+- make all
-- ./runtests vet
-- ./runtests test
-- ./runtests gfmrun
-- ./cli-v1-to-v2 --selftest
-- ./runtests migrations
-- ./runtests toc

CHANGELOG.md

@@ -35,6 +35,8 @@
 ## [Unreleased] - (1.x series)
 ### Added
 - Flag type code generation via `go generate`
+- Write to stderr and exit 1 if action returns non-nil error
+- Added support for TOML to the `altsrc` loader
 
 ### Changed
 - Raise minimum tested/supported Go version to 1.2+

GNUmakefile

@@ -0,0 +1,37 @@
+default: test
+
+deps:
+	go get golang.org/x/tools/cmd/goimports || true
+	go get github.com/urfave/gfmrun/... || true
+	go list ./... \
+		| xargs go list -f '{{ join .Deps "\n" }}{{ printf "\n" }}{{ join .TestImports "\n" }}' \
+		| grep -v github.com/urfave/cli \
+		| xargs go get
+	@if [ ! -f node_modules/.bin/markdown-toc ]; then \
+		npm install markdown-toc ; \
+	fi
+
+gen: deps
+	./runtests gen
+
+vet:
+	./runtests vet
+
+gfmrun:
+	./runtests gfmrun
+
+v1-to-v2:
+	./cli-v1-to-v2 --selftest
+
+migrations:
+	./runtests migrations
+
+toc:
+	./runtests toc
+
+test: deps
+	./runtests test
+
+all: gen vet test gfmrun v1-to-v2 migrations toc
+
+.PHONY: default gen vet test gfmrun migrations toc v1-to-v2 deps all

README.md

@@ -31,7 +31,8 @@ applications in an expressive way.
     + [Placeholder Values](#placeholder-values)
     + [Alternate Names](#alternate-names)
     + [Values from the Environment](#values-from-the-environment)
-    + [Values from alternate input sources (YAML and others)](#values-from-alternate-input-sources-yaml-and-others)
+    + [Values from alternate input sources (YAML, TOML, and others)](#values-from-alternate-input-sources-yaml-toml-and-others)
+    + [Default Values for help output](#default-values-for-help-output)
   * [Subcommands](#subcommands)
   * [Subcommands categories](#subcommands-categories)
   * [Exit code](#exit-code)
@@ -520,10 +521,14 @@ func main() {
 }
 ```
 
-#### Values from alternate input sources (YAML and others)
+#### Values from alternate input sources (YAML, TOML, and others)
 
 There is a separate package altsrc that adds support for getting flag values
-from other input sources like YAML.
+from other file input sources.
+
+Currently supported input source formats:
+* YAML
+* TOML
 
 In order to get values for a flag from an alternate input source the following
 code would be added to wrap an existing cli.Flag like below:
@@ -545,9 +550,9 @@ the yaml input source for any flags that are defined on that command.  As a note
 the "load" flag used would also have to be defined on the command flags in order
 for this code snipped to work.
 
-Currently only YAML and JSON files are supported but developers can add support
+Currently only the aboved specified formats are supported but developers can
-for other input sources by implementing the altsrc.InputSourceContext for their
+add support for other input sources by implementing the
-given sources.
+altsrc.InputSourceContext for their given sources.
 
 Here is a more complete sample of a command using YAML support:
 
@@ -585,6 +590,48 @@ func main() {
 }
 ```
 
+#### Default Values for help output
+
+Sometimes it's useful to specify a flag's default help-text value within the flag declaration. This can be useful if the default value for a flag is a computed value. The default value can be set via the `DefaultText` struct field.
+
+For example this:
+
+<!-- {
+  "args": ["&#45;&#45;help"],
+  "output": "&#45;&#45;port value"
+} -->
+```go
+package main
+
+import (
+  "os"
+
+  "gopkg.in/urfave/cli.v2"
+)
+
+func main() {
+  app := &cli.App{
+    Flags: []cli.Flag{
+      &cli.IntFlag{
+        Name:    "port",
+        Usage:   "Use a randomized port",
+        Value: 0,
+        DefaultText: "random",
+      },
+    },
+  }
+
+  app.Run(os.Args)
+}
+```
+
+Will result in help output like:
+
+```
+--port value  Use a randomized port (default: random)
+```
+
+
 ### Subcommands
 
 Subcommands can be defined for a more git-like command line app.

altsrc/flag.go

@@ -5,7 +5,7 @@ import (
 	"os"
 	"strconv"
 
-	"github.com/urfave/cli"
+	"gopkg.in/urfave/cli.v2"
 )
 
 // FlagInputSourceExtension is an extension interface of cli.Flag that

altsrc/flag_generated.go

@@ -3,7 +3,7 @@ package altsrc
 import (
 	"flag"
 
-	"github.com/urfave/cli"
+	"gopkg.in/urfave/cli.v2"
 )
 
 // WARNING: This file is generated!

altsrc/flag_test.go

@@ -8,7 +8,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/urfave/cli"
+	"gopkg.in/urfave/cli.v2"
 )
 
 type testApplyInputSource struct {

altsrc/input_source_context.go

@@ -3,7 +3,7 @@ package altsrc
 import (
 	"time"
 
-	"github.com/urfave/cli"
+	"gopkg.in/urfave/cli.v2"
 )
 
 // InputSourceContext is an interface used to allow

altsrc/json_command_test.go

@@ -6,7 +6,7 @@ import (
 	"os"
 	"testing"
 
-	"github.com/urfave/cli"
+	"gopkg.in/urfave/cli.v2"
 )
 
 const (

altsrc/json_source_context.go

@@ -8,7 +8,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/urfave/cli"
+	"gopkg.in/urfave/cli.v2"
 )
 
 // NewJSONSourceFromFlagFunc returns a func that takes a cli.Context

altsrc/map_input_source.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/urfave/cli"
+	"gopkg.in/urfave/cli.v2"
 )
 
 // MapInputSource implements InputSourceContext to return

altsrc/toml_command_test.go

@@ -0,0 +1,310 @@
+// Disabling building of toml support in cases where golang is 1.0 or 1.1
+// as the encoding library is not implemented or supported.
+
+// +build go1.2
+
+package altsrc
+
+import (
+	"flag"
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"gopkg.in/urfave/cli.v2"
+)
+
+func TestCommandTomFileTest(t *testing.T) {
+	app := (&cli.App{})
+	set := flag.NewFlagSet("test", 0)
+	ioutil.WriteFile("current.toml", []byte("test = 15"), 0666)
+	defer os.Remove("current.toml")
+	test := []string{"test-cmd", "--load", "current.toml"}
+	set.Parse(test)
+
+	c := cli.NewContext(app, set, nil)
+
+	command := &cli.Command{
+		Name:        "test-cmd",
+		Aliases:     []string{"tc"},
+		Usage:       "this is for testing",
+		Description: "testing",
+		Action: func(c *cli.Context) error {
+			val := c.Int("test")
+			expect(t, val, 15)
+			return nil
+		},
+		Flags: []cli.Flag{
+			NewIntFlag(&cli.IntFlag{Name: "test"}),
+			&cli.StringFlag{Name: "load"}},
+	}
+	command.Before = InitInputSourceWithContext(command.Flags, NewTomlSourceFromFlagFunc("load"))
+	err := command.Run(c)
+
+	expect(t, err, nil)
+}
+
+func TestCommandTomlFileTestGlobalEnvVarWins(t *testing.T) {
+	app := (&cli.App{})
+	set := flag.NewFlagSet("test", 0)
+	ioutil.WriteFile("current.toml", []byte("test = 15"), 0666)
+	defer os.Remove("current.toml")
+
+	os.Setenv("THE_TEST", "10")
+	defer os.Setenv("THE_TEST", "")
+	test := []string{"test-cmd", "--load", "current.toml"}
+	set.Parse(test)
+
+	c := cli.NewContext(app, set, nil)
+
+	command := &cli.Command{
+		Name:        "test-cmd",
+		Aliases:     []string{"tc"},
+		Usage:       "this is for testing",
+		Description: "testing",
+		Action: func(c *cli.Context) error {
+			val := c.Int("test")
+			expect(t, val, 10)
+			return nil
+		},
+		Flags: []cli.Flag{
+			NewIntFlag(&cli.IntFlag{Name: "test", EnvVars: []string{"THE_TEST"}}),
+			&cli.StringFlag{Name: "load"}},
+	}
+	command.Before = InitInputSourceWithContext(command.Flags, NewTomlSourceFromFlagFunc("load"))
+
+	err := command.Run(c)
+
+	expect(t, err, nil)
+}
+
+func TestCommandTomlFileTestGlobalEnvVarWinsNested(t *testing.T) {
+	app := (&cli.App{})
+	set := flag.NewFlagSet("test", 0)
+	ioutil.WriteFile("current.toml", []byte("[top]\ntest = 15"), 0666)
+	defer os.Remove("current.toml")
+
+	os.Setenv("THE_TEST", "10")
+	defer os.Setenv("THE_TEST", "")
+	test := []string{"test-cmd", "--load", "current.toml"}
+	set.Parse(test)
+
+	c := cli.NewContext(app, set, nil)
+
+	command := &cli.Command{
+		Name:        "test-cmd",
+		Aliases:     []string{"tc"},
+		Usage:       "this is for testing",
+		Description: "testing",
+		Action: func(c *cli.Context) error {
+			val := c.Int("top.test")
+			expect(t, val, 10)
+			return nil
+		},
+		Flags: []cli.Flag{
+			NewIntFlag(&cli.IntFlag{Name: "top.test", EnvVars: []string{"THE_TEST"}}),
+			&cli.StringFlag{Name: "load"}},
+	}
+	command.Before = InitInputSourceWithContext(command.Flags, NewTomlSourceFromFlagFunc("load"))
+
+	err := command.Run(c)
+
+	expect(t, err, nil)
+}
+
+func TestCommandTomlFileTestSpecifiedFlagWins(t *testing.T) {
+	app := (&cli.App{})
+	set := flag.NewFlagSet("test", 0)
+	ioutil.WriteFile("current.toml", []byte("test = 15"), 0666)
+	defer os.Remove("current.toml")
+
+	test := []string{"test-cmd", "--load", "current.toml", "--test", "7"}
+	set.Parse(test)
+
+	c := cli.NewContext(app, set, nil)
+
+	command := &cli.Command{
+		Name:        "test-cmd",
+		Aliases:     []string{"tc"},
+		Usage:       "this is for testing",
+		Description: "testing",
+		Action: func(c *cli.Context) error {
+			val := c.Int("test")
+			expect(t, val, 7)
+			return nil
+		},
+		Flags: []cli.Flag{
+			NewIntFlag(&cli.IntFlag{Name: "test"}),
+			&cli.StringFlag{Name: "load"}},
+	}
+	command.Before = InitInputSourceWithContext(command.Flags, NewTomlSourceFromFlagFunc("load"))
+
+	err := command.Run(c)
+
+	expect(t, err, nil)
+}
+
+func TestCommandTomlFileTestSpecifiedFlagWinsNested(t *testing.T) {
+	app := (&cli.App{})
+	set := flag.NewFlagSet("test", 0)
+	ioutil.WriteFile("current.toml", []byte(`[top]
+  test = 15`), 0666)
+	defer os.Remove("current.toml")
+
+	test := []string{"test-cmd", "--load", "current.toml", "--top.test", "7"}
+	set.Parse(test)
+
+	c := cli.NewContext(app, set, nil)
+
+	command := &cli.Command{
+		Name:        "test-cmd",
+		Aliases:     []string{"tc"},
+		Usage:       "this is for testing",
+		Description: "testing",
+		Action: func(c *cli.Context) error {
+			val := c.Int("top.test")
+			expect(t, val, 7)
+			return nil
+		},
+		Flags: []cli.Flag{
+			NewIntFlag(&cli.IntFlag{Name: "top.test"}),
+			&cli.StringFlag{Name: "load"}},
+	}
+	command.Before = InitInputSourceWithContext(command.Flags, NewTomlSourceFromFlagFunc("load"))
+
+	err := command.Run(c)
+
+	expect(t, err, nil)
+}
+
+func TestCommandTomlFileTestDefaultValueFileWins(t *testing.T) {
+	app := (&cli.App{})
+	set := flag.NewFlagSet("test", 0)
+	ioutil.WriteFile("current.toml", []byte("test = 15"), 0666)
+	defer os.Remove("current.toml")
+
+	test := []string{"test-cmd", "--load", "current.toml"}
+	set.Parse(test)
+
+	c := cli.NewContext(app, set, nil)
+
+	command := &cli.Command{
+		Name:        "test-cmd",
+		Aliases:     []string{"tc"},
+		Usage:       "this is for testing",
+		Description: "testing",
+		Action: func(c *cli.Context) error {
+			val := c.Int("test")
+			expect(t, val, 15)
+			return nil
+		},
+		Flags: []cli.Flag{
+			NewIntFlag(&cli.IntFlag{Name: "test", Value: 7}),
+			&cli.StringFlag{Name: "load"}},
+	}
+	command.Before = InitInputSourceWithContext(command.Flags, NewTomlSourceFromFlagFunc("load"))
+
+	err := command.Run(c)
+
+	expect(t, err, nil)
+}
+
+func TestCommandTomlFileTestDefaultValueFileWinsNested(t *testing.T) {
+	app := (&cli.App{})
+	set := flag.NewFlagSet("test", 0)
+	ioutil.WriteFile("current.toml", []byte("[top]\ntest = 15"), 0666)
+	defer os.Remove("current.toml")
+
+	test := []string{"test-cmd", "--load", "current.toml"}
+	set.Parse(test)
+
+	c := cli.NewContext(app, set, nil)
+
+	command := &cli.Command{
+		Name:        "test-cmd",
+		Aliases:     []string{"tc"},
+		Usage:       "this is for testing",
+		Description: "testing",
+		Action: func(c *cli.Context) error {
+			val := c.Int("top.test")
+			expect(t, val, 15)
+			return nil
+		},
+		Flags: []cli.Flag{
+			NewIntFlag(&cli.IntFlag{Name: "top.test", Value: 7}),
+			&cli.StringFlag{Name: "load"}},
+	}
+	command.Before = InitInputSourceWithContext(command.Flags, NewTomlSourceFromFlagFunc("load"))
+
+	err := command.Run(c)
+
+	expect(t, err, nil)
+}
+
+func TestCommandTomlFileFlagHasDefaultGlobalEnvTomlSetGlobalEnvWins(t *testing.T) {
+	app := (&cli.App{})
+	set := flag.NewFlagSet("test", 0)
+	ioutil.WriteFile("current.toml", []byte("test = 15"), 0666)
+	defer os.Remove("current.toml")
+
+	os.Setenv("THE_TEST", "11")
+	defer os.Setenv("THE_TEST", "")
+
+	test := []string{"test-cmd", "--load", "current.toml"}
+	set.Parse(test)
+
+	c := cli.NewContext(app, set, nil)
+
+	command := &cli.Command{
+		Name:        "test-cmd",
+		Aliases:     []string{"tc"},
+		Usage:       "this is for testing",
+		Description: "testing",
+		Action: func(c *cli.Context) error {
+			val := c.Int("test")
+			expect(t, val, 11)
+			return nil
+		},
+		Flags: []cli.Flag{
+			NewIntFlag(&cli.IntFlag{Name: "test", Value: 7, EnvVars: []string{"THE_TEST"}}),
+			&cli.StringFlag{Name: "load"}},
+	}
+	command.Before = InitInputSourceWithContext(command.Flags, NewTomlSourceFromFlagFunc("load"))
+	err := command.Run(c)
+
+	expect(t, err, nil)
+}
+
+func TestCommandTomlFileFlagHasDefaultGlobalEnvTomlSetGlobalEnvWinsNested(t *testing.T) {
+	app := (&cli.App{})
+	set := flag.NewFlagSet("test", 0)
+	ioutil.WriteFile("current.toml", []byte("[top]\ntest = 15"), 0666)
+	defer os.Remove("current.toml")
+
+	os.Setenv("THE_TEST", "11")
+	defer os.Setenv("THE_TEST", "")
+
+	test := []string{"test-cmd", "--load", "current.toml"}
+	set.Parse(test)
+
+	c := cli.NewContext(app, set, nil)
+
+	command := &cli.Command{
+		Name:        "test-cmd",
+		Aliases:     []string{"tc"},
+		Usage:       "this is for testing",
+		Description: "testing",
+		Action: func(c *cli.Context) error {
+			val := c.Int("top.test")
+			expect(t, val, 11)
+			return nil
+		},
+		Flags: []cli.Flag{
+			NewIntFlag(&cli.IntFlag{Name: "top.test", Value: 7, EnvVars: []string{"THE_TEST"}}),
+			&cli.StringFlag{Name: "load"}},
+	}
+	command.Before = InitInputSourceWithContext(command.Flags, NewTomlSourceFromFlagFunc("load"))
+	err := command.Run(c)
+
+	expect(t, err, nil)
+}

altsrc/toml_file_loader.go

@@ -0,0 +1,113 @@
+// Disabling building of toml support in cases where golang is 1.0 or 1.1
+// as the encoding library is not implemented or supported.
+
+// +build go1.2
+
+package altsrc
+
+import (
+	"fmt"
+	"reflect"
+
+	"github.com/BurntSushi/toml"
+	"gopkg.in/urfave/cli.v2"
+)
+
+type tomlMap struct {
+	Map map[interface{}]interface{}
+}
+
+func unmarshalMap(i interface{}) (ret map[interface{}]interface{}, err error) {
+	ret = make(map[interface{}]interface{})
+	m := i.(map[string]interface{})
+	for key, val := range m {
+		v := reflect.ValueOf(val)
+		switch v.Kind() {
+		case reflect.Bool:
+			ret[key] = val.(bool)
+		case reflect.String:
+			ret[key] = val.(string)
+		case reflect.Int:
+			ret[key] = int(val.(int))
+		case reflect.Int8:
+			ret[key] = int(val.(int8))
+		case reflect.Int16:
+			ret[key] = int(val.(int16))
+		case reflect.Int32:
+			ret[key] = int(val.(int32))
+		case reflect.Int64:
+			ret[key] = int(val.(int64))
+		case reflect.Uint:
+			ret[key] = int(val.(uint))
+		case reflect.Uint8:
+			ret[key] = int(val.(uint8))
+		case reflect.Uint16:
+			ret[key] = int(val.(uint16))
+		case reflect.Uint32:
+			ret[key] = int(val.(uint32))
+		case reflect.Uint64:
+			ret[key] = int(val.(uint64))
+		case reflect.Float32:
+			ret[key] = float64(val.(float32))
+		case reflect.Float64:
+			ret[key] = float64(val.(float64))
+		case reflect.Map:
+			if tmp, err := unmarshalMap(val); err == nil {
+				ret[key] = tmp
+			} else {
+				return nil, err
+			}
+		case reflect.Array:
+			fallthrough // [todo] - Support array type
+		default:
+			return nil, fmt.Errorf("Unsupported: type = %#v", v.Kind())
+		}
+	}
+	return ret, nil
+}
+
+func (self *tomlMap) UnmarshalTOML(i interface{}) error {
+	if tmp, err := unmarshalMap(i); err == nil {
+		self.Map = tmp
+	} else {
+		return err
+	}
+	return nil
+}
+
+type tomlSourceContext struct {
+	FilePath string
+}
+
+// NewTomlSourceFromFile creates a new TOML InputSourceContext from a filepath.
+func NewTomlSourceFromFile(file string) (InputSourceContext, error) {
+	tsc := &tomlSourceContext{FilePath: file}
+	var results tomlMap = tomlMap{}
+	if err := readCommandToml(tsc.FilePath, &results); err != nil {
+		return nil, fmt.Errorf("Unable to load TOML file '%s': inner error: \n'%v'", tsc.FilePath, err.Error())
+	}
+	return &MapInputSource{valueMap: results.Map}, nil
+}
+
+// NewTomlSourceFromFlagFunc creates a new TOML InputSourceContext from a provided flag name and source context.
+func NewTomlSourceFromFlagFunc(flagFileName string) func(context *cli.Context) (InputSourceContext, error) {
+	return func(context *cli.Context) (InputSourceContext, error) {
+		filePath := context.String(flagFileName)
+		return NewTomlSourceFromFile(filePath)
+	}
+}
+
+func readCommandToml(filePath string, container interface{}) (err error) {
+	b, err := loadDataFrom(filePath)
+	if err != nil {
+		return err
+	}
+
+	err = toml.Unmarshal(b, container)
+	if err != nil {
+		return err
+	}
+
+	err = nil
+	return
+}

altsrc/yaml_command_test.go

@@ -11,7 +11,7 @@ import (
 	"os"
 	"testing"
 
-	"github.com/urfave/cli"
+	"gopkg.in/urfave/cli.v2"
 )
 
 func TestCommandYamlFileTest(t *testing.T) {

altsrc/yaml_file_loader.go

@@ -12,7 +12,7 @@ import (
 	"net/url"
 	"os"
 
-	"github.com/urfave/cli"
+	"gopkg.in/urfave/cli.v2"
 
 	"gopkg.in/yaml.v2"
 )

app_test.go

@@ -13,6 +13,19 @@ import (
 	"testing"
 )
 
+var (
+	lastExitCode = 0
+	fakeOsExiter = func(rc int) {
+		lastExitCode = rc
+	}
+	fakeErrWriter = &bytes.Buffer{}
+)
+
+func init() {
+	OsExiter = fakeOsExiter
+	ErrWriter = fakeErrWriter
+}
+
 type opCounts struct {
 	Total, ShellComplete, OnUsageError, Before, CommandNotFound, Action, After, SubCommand int
 }

errors.go

@@ -98,5 +98,11 @@ func HandleExitCoder(err error) {
 		for _, merr := range multiErr.Errors() {
 			HandleExitCoder(merr)
 		}
+		return
+	}
+
+	if err.Error() != "" {
+		fmt.Fprintln(ErrWriter, err)
 	}
+	OsExiter(1)
 }

errors_test.go

@@ -1,8 +1,8 @@
 package cli
 
 import (
+	"bytes"
 	"errors"
-	"os"
 	"testing"
 )
 
@@ -15,7 +15,7 @@ func TestHandleExitCoder_nil(t *testing.T) {
 		called = true
 	}
 
-	defer func() { OsExiter = os.Exit }()
+	defer func() { OsExiter = fakeOsExiter }()
 
 	HandleExitCoder(nil)
 
@@ -32,7 +32,7 @@ func TestHandleExitCoder_ExitCoder(t *testing.T) {
 		called = true
 	}
 
-	defer func() { OsExiter = os.Exit }()
+	defer func() { OsExiter = fakeOsExiter }()
 
 	HandleExitCoder(Exit("galactic perimeter breach", 9))
 
@@ -49,7 +49,7 @@ func TestHandleExitCoder_MultiErrorWithExitCoder(t *testing.T) {
 		called = true
 	}
 
-	defer func() { OsExiter = os.Exit }()
+	defer func() { OsExiter = fakeOsExiter }()
 
 	exitErr := Exit("galactic perimeter breach", 9)
 	err := newMultiError(errors.New("wowsa"), errors.New("egad"), exitErr)
@@ -58,3 +58,49 @@ func TestHandleExitCoder_MultiErrorWithExitCoder(t *testing.T) {
 	expect(t, exitCode, 9)
 	expect(t, called, true)
 }
+
+func TestHandleExitCoder_ErrorWithMessage(t *testing.T) {
+	exitCode := 0
+	called := false
+
+	OsExiter = func(rc int) {
+		exitCode = rc
+		called = true
+	}
+	ErrWriter = &bytes.Buffer{}
+
+	defer func() {
+		OsExiter = fakeOsExiter
+		ErrWriter = fakeErrWriter
+	}()
+
+	err := errors.New("gourd havens")
+	HandleExitCoder(err)
+
+	expect(t, exitCode, 1)
+	expect(t, called, true)
+	expect(t, ErrWriter.(*bytes.Buffer).String(), "gourd havens\n")
+}
+
+func TestHandleExitCoder_ErrorWithoutMessage(t *testing.T) {
+	exitCode := 0
+	called := false
+
+	OsExiter = func(rc int) {
+		exitCode = rc
+		called = true
+	}
+	ErrWriter = &bytes.Buffer{}
+
+	defer func() {
+		OsExiter = fakeOsExiter
+		ErrWriter = fakeErrWriter
+	}()
+
+	err := errors.New("")
+	HandleExitCoder(err)
+
+	expect(t, exitCode, 1)
+	expect(t, called, true)
+	expect(t, ErrWriter.(*bytes.Buffer).String(), "")
+}

flag.go

@@ -736,7 +736,6 @@ func stringifyFlag(f Flag) string {
 	needsPlaceholder := false
 	defaultValueString := ""
 	val := fv.FieldByName("Value")
-
 	if val.IsValid() {
 		needsPlaceholder = val.Kind() != reflect.Bool
 		defaultValueString = fmt.Sprintf(" (default: %v)", val.Interface())
@@ -746,6 +745,12 @@ func stringifyFlag(f Flag) string {
 		}
 	}
 
+	helpText := fv.FieldByName("DefaultText")
+	if helpText.IsValid() && helpText.String() != "" {
+		needsPlaceholder = val.Kind() != reflect.Bool
+		defaultValueString = fmt.Sprintf(" (default: %s)", helpText.String())
+	}
+
 	if defaultValueString == " (default: )" {
 		defaultValueString = ""
 	}

flag_generated.go

@@ -16,6 +16,7 @@ type BoolFlag struct {
 	EnvVars     []string
 	Hidden      bool
 	Value       bool
+	DefaultText string
 	Destination *bool
 }
 
@@ -59,6 +60,7 @@ type DurationFlag struct {
 	EnvVars     []string
 	Hidden      bool
 	Value       time.Duration
+	DefaultText string
 	Destination *time.Duration
 }
 
@@ -102,6 +104,7 @@ type Float64Flag struct {
 	EnvVars     []string
 	Hidden      bool
 	Value       float64
+	DefaultText string
 	Destination *float64
 }
 
@@ -139,12 +142,13 @@ func lookupFloat64(name string, set *flag.FlagSet) float64 {
 
 // GenericFlag is a flag with type Generic
 type GenericFlag struct {
-	Name    string
+	Name        string
-	Aliases []string
+	Aliases     []string
-	Usage   string
+	Usage       string
-	EnvVars []string
+	EnvVars     []string
-	Hidden  bool
+	Hidden      bool
-	Value   Generic
+	Value       Generic
+	DefaultText string
 }
 
 // String returns a readable representation of this value
@@ -187,6 +191,7 @@ type Int64Flag struct {
 	EnvVars     []string
 	Hidden      bool
 	Value       int64
+	DefaultText string
 	Destination *int64
 }
 
@@ -230,6 +235,7 @@ type IntFlag struct {
 	EnvVars     []string
 	Hidden      bool
 	Value       int
+	DefaultText string
 	Destination *int
 }
 
@@ -267,12 +273,13 @@ func lookupInt(name string, set *flag.FlagSet) int {
 
 // IntSliceFlag is a flag with type *IntSlice
 type IntSliceFlag struct {
-	Name    string
+	Name        string
-	Aliases []string
+	Aliases     []string
-	Usage   string
+	Usage       string
-	EnvVars []string
+	EnvVars     []string
-	Hidden  bool
+	Hidden      bool
-	Value   *IntSlice
+	Value       *IntSlice
+	DefaultText string
 }
 
 // String returns a readable representation of this value
@@ -309,12 +316,13 @@ func lookupIntSlice(name string, set *flag.FlagSet) []int {
 
 // Int64SliceFlag is a flag with type *Int64Slice
 type Int64SliceFlag struct {
-	Name    string
+	Name        string
-	Aliases []string
+	Aliases     []string
-	Usage   string
+	Usage       string
-	EnvVars []string
+	EnvVars     []string
-	Hidden  bool
+	Hidden      bool
-	Value   *Int64Slice
+	Value       *Int64Slice
+	DefaultText string
 }
 
 // String returns a readable representation of this value
@@ -351,12 +359,13 @@ func lookupInt64Slice(name string, set *flag.FlagSet) []int64 {
 
 // Float64SliceFlag is a flag with type *Float64Slice
 type Float64SliceFlag struct {
-	Name    string
+	Name        string
-	Aliases []string
+	Aliases     []string
-	Usage   string
+	Usage       string
-	EnvVars []string
+	EnvVars     []string
-	Hidden  bool
+	Hidden      bool
-	Value   *Float64Slice
+	Value       *Float64Slice
+	DefaultText string
 }
 
 // String returns a readable representation of this value
@@ -399,6 +408,7 @@ type StringFlag struct {
 	EnvVars     []string
 	Hidden      bool
 	Value       string
+	DefaultText string
 	Destination *string
 }
 
@@ -436,12 +446,13 @@ func lookupString(name string, set *flag.FlagSet) string {
 
 // StringSliceFlag is a flag with type *StringSlice
 type StringSliceFlag struct {
-	Name    string
+	Name        string
-	Aliases []string
+	Aliases     []string
-	Usage   string
+	Usage       string
-	EnvVars []string
+	EnvVars     []string
-	Hidden  bool
+	Hidden      bool
-	Value   *StringSlice
+	Value       *StringSlice
+	DefaultText string
 }
 
 // String returns a readable representation of this value
@@ -484,6 +495,7 @@ type Uint64Flag struct {
 	EnvVars     []string
 	Hidden      bool
 	Value       uint64
+	DefaultText string
 	Destination *uint64
 }
 
@@ -527,6 +539,7 @@ type UintFlag struct {
 	EnvVars     []string
 	Hidden      bool
 	Value       uint
+	DefaultText string
 	Destination *uint
 }
 

flag_test.go

@@ -67,6 +67,16 @@ func TestStringFlagHelpOutput(t *testing.T) {
 	}
 }
 
+func TestStringFlagDefaultText(t *testing.T) {
+	flag := &StringFlag{Name: "foo", Aliases: nil, Usage: "amount of `foo` requested", Value: "none", DefaultText: "all of it"}
+	expected := "--foo foo\tamount of foo requested (default: all of it)"
+	output := flag.String()
+
+	if output != expected {
+		t.Errorf("%q does not match %q", output, expected)
+	}
+}
+
 func TestStringFlagWithEnvVarHelpOutput(t *testing.T) {
 	os.Clearenv()
 	os.Setenv("APP_FOO", "derp")
@@ -482,7 +492,6 @@ func TestFloat64FlagApply_SetsAllNames(t *testing.T) {
 	expect(t, v, float64(43.33333))
 }
 
-
 var float64SliceFlagTests = []struct {
 	name     string
 	aliases  []string
@@ -523,8 +532,6 @@ func TestFloat64SliceFlagWithEnvVarHelpOutput(t *testing.T) {
 	}
 }
 
-
-
 var genericFlagTests = []struct {
 	name     string
 	value    Generic
@@ -1100,7 +1107,6 @@ func TestParseMultiFloat64FromEnvCascade(t *testing.T) {
 	a.Run([]string{"run"})
 }
 
-
 func TestParseMultiFloat64SliceFromEnv(t *testing.T) {
 	os.Clearenv()
 	os.Setenv("APP_INTERVALS", "0.1,-10.5")
@@ -1141,7 +1147,6 @@ func TestParseMultiFloat64SliceFromEnvCascade(t *testing.T) {
 	}).Run([]string{"run"})
 }
 
-
 func TestParseMultiBool(t *testing.T) {
 	a := App{
 		Flags: []Flag{

generate-flag-types

@@ -145,6 +145,7 @@ def _write_cli_flag_types(outfile, types):
             EnvVars []string
             Hidden bool
             Value {type}
+            DefaultText string
         """.format(**typedef))
 
         if typedef['dest']:
@@ -193,6 +194,8 @@ def _write_altsrc_flag_types(outfile, types):
     _fwrite(outfile, """\
         package altsrc
 
+        import "gopkg.in/urfave/cli.v2"
+
         // WARNING: This file is generated!
 
         """)

runtests

@@ -61,6 +61,10 @@ def _test():
 
 @_target
 def _gfmrun():
+    go_version = check_output('go version'.split()).split()[2]
+    if go_version < 'go1.3':
+        print('runtests: skip on {}'.format(go_version), file=sys.stderr)
+        return
     _run(['gfmrun', '-c', str(_gfmrun_count()), '-s', 'README.md'])
 
 
@@ -71,6 +75,11 @@ def _vet():
 
 @_target
 def _migrations():
+    go_version = check_output('go version'.split()).split()[2]
+    if go_version < 'go1.3':
+        print('runtests: skip on {}'.format(go_version), file=sys.stderr)
+        return
+
     migration_script = os.path.abspath(
         os.environ.get('V1TOV2', './cli-v1-to-v2')
     )