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Merge pull request #137 from alexflint/optional-long 

Optional long names
This commit is contained in:
Alex Flint 2021-04-16 21:03:14 -07:00 committed by GitHub
parent 113aef7114 172800ff9a
commit f4eb7f3a58
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GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 132 additions and 32 deletions
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10
README.md
View File

@ -244,21 +244,23 @@ someprogram 4.3.0
```go
var args struct {
Short string `arg:"-s"`
Long string `arg:"--custom-long-option"`
ShortAndLong string `arg:"-x,--my-option"`
Short string `arg:"-s"`
Long string `arg:"--custom-long-option"`
ShortAndLong string `arg:"-x,--my-option"`
OnlyShort string `arg:"-o,--"`
}
arg.MustParse(&args)
```
```shell
$ ./example --help
Usage: [--short SHORT] [--custom-long-option CUSTOM-LONG-OPTION] [--my-option MY-OPTION]
Usage: example [-o ONLYSHORT] [--short SHORT] [--custom-long-option CUSTOM-LONG-OPTION] [--my-option MY-OPTION]
Options:
--short SHORT, -s SHORT
--custom-long-option CUSTOM-LONG-OPTION
--my-option MY-OPTION, -x MY-OPTION
-o ONLYSHORT
--help, -h display this help and exit
```

26
parse.go
View File

@ -47,9 +47,9 @@ func (p path) Child(f reflect.StructField) path {
// spec represents a command line option
type spec struct {
dest path
typ reflect.Type
long string
short string
field reflect.StructField // the struct field from which this option was created
long string // the --long form for this option, or empty if none
short string // the -s short form for this option, or empty if none
multiple bool
required bool
positional bool
@ -275,9 +275,9 @@ func cmdFromStruct(name string, dest path, t reflect.Type) (*command, error) {
// duplicate the entire path to avoid slice overwrites
subdest := dest.Child(field)
spec := spec{
dest: subdest,
long: strings.ToLower(field.Name),
typ: field.Type,
dest: subdest,
field: field,
long: strings.ToLower(field.Name),
}
help, exists := field.Tag.Lookup("help")
@ -363,8 +363,10 @@ func cmdFromStruct(name string, dest path, t reflect.Type) (*command, error) {
placeholder, hasPlaceholder := field.Tag.Lookup("placeholder")
if hasPlaceholder {
spec.placeholder = placeholder
} else {
} else if spec.long != "" {
spec.placeholder = strings.ToUpper(spec.long)
} else {
spec.placeholder = strings.ToUpper(spec.field.Name)
}
// Check whether this field is supported. It's good to do this here rather than
@ -592,7 +594,7 @@ func (p *Parser) process(args []string) error {
if i+1 == len(args) {
return fmt.Errorf("missing value for %s", arg)
}
if !nextIsNumeric(spec.typ, args[i+1]) && isFlag(args[i+1]) {
if !nextIsNumeric(spec.field.Type, args[i+1]) && isFlag(args[i+1]) {
return fmt.Errorf("missing value for %s", arg)
}
value = args[i+1]
@ -617,13 +619,13 @@ func (p *Parser) process(args []string) error {
if spec.multiple {
err := setSlice(p.val(spec.dest), positionals, true)
if err != nil {
return fmt.Errorf("error processing %s: %v", spec.long, err)
return fmt.Errorf("error processing %s: %v", spec.field.Name, err)
}
positionals = nil
} else {
err := scalar.ParseValue(p.val(spec.dest), positionals[0])
if err != nil {
return fmt.Errorf("error processing %s: %v", spec.long, err)
return fmt.Errorf("error processing %s: %v", spec.field.Name, err)
}
positionals = positionals[1:]
}
@ -638,8 +640,8 @@ func (p *Parser) process(args []string) error {
continue
}
name := spec.long
if !spec.positional {
name := strings.ToLower(spec.field.Name)
if spec.long != "" && !spec.positional {
name = "--" + spec.long
}

12
parse_test.go
View File

@ -231,6 +231,18 @@ func TestPlaceholder(t *testing.T) {
assert.NoError(t, err)
}
func TestNoLongName(t *testing.T) {
var args struct {
ShortOnly string `arg:"-s,--"`
EnvOnly string `arg:"--,env"`
}
setenv(t, "ENVONLY", "TestVal")
err := parse("-s TestVal2", &args)
assert.NoError(t, err)
assert.Equal(t, "TestVal", args.EnvOnly)
assert.Equal(t, "TestVal2", args.ShortOnly)
}
func TestCaseSensitive(t *testing.T) {
var args struct {
Lower bool `arg:"-v"`

58
usage.go
View File

@ -36,12 +36,15 @@ func (p *Parser) WriteUsage(w io.Writer) {
// writeUsageForCommand writes usage information for the given subcommand
func (p *Parser) writeUsageForCommand(w io.Writer, cmd *command) {
var positionals, options []*spec
var positionals, longOptions, shortOptions []*spec
for _, spec := range cmd.specs {
if spec.positional {
switch {
case spec.positional:
positionals = append(positionals, spec)
} else {
options = append(options, spec)
case spec.long != "":
longOptions = append(longOptions, spec)
case spec.short != "":
shortOptions = append(shortOptions, spec)
}
}
@ -64,7 +67,19 @@ func (p *Parser) writeUsageForCommand(w io.Writer, cmd *command) {
}
// write the option component of the usage message
for _, spec := range options {
for _, spec := range shortOptions {
// prefix with a space
fmt.Fprint(w, " ")
if !spec.required {
fmt.Fprint(w, "[")
}
fmt.Fprint(w, synopsis(spec, "-"+spec.short))
if !spec.required {
fmt.Fprint(w, "]")
}
}
for _, spec := range longOptions {
// prefix with a space
fmt.Fprint(w, " ")
if !spec.required {
@ -144,12 +159,15 @@ func (p *Parser) WriteHelp(w io.Writer) {
// writeHelp writes the usage string for the given subcommand
func (p *Parser) writeHelpForCommand(w io.Writer, cmd *command) {
var positionals, options []*spec
var positionals, longOptions, shortOptions []*spec
for _, spec := range cmd.specs {
if spec.positional {
switch {
case spec.positional:
positionals = append(positionals, spec)
} else {
options = append(options, spec)
case spec.long != "":
longOptions = append(longOptions, spec)
case spec.short != "":
shortOptions = append(shortOptions, spec)
}
}
@ -166,10 +184,13 @@ func (p *Parser) writeHelpForCommand(w io.Writer, cmd *command) {
}
}
// write the list of options
if len(options) > 0 || cmd.parent == nil {
// write the list of options with the short-only ones first to match the usage string
if len(shortOptions)+len(longOptions) > 0 || cmd.parent == nil {
fmt.Fprint(w, "\nOptions:\n")
for _, spec := range options {
for _, spec := range shortOptions {
p.printOption(w, spec)
}
for _, spec := range longOptions {
p.printOption(w, spec)
}
}
@ -215,11 +236,16 @@ func (p *Parser) writeHelpForCommand(w io.Writer, cmd *command) {
}
func (p *Parser) printOption(w io.Writer, spec *spec) {
left := synopsis(spec, "--"+spec.long)
if spec.short != "" {
left += ", " + synopsis(spec, "-"+spec.short)
ways := make([]string, 0, 2)
if spec.long != "" {
ways = append(ways, synopsis(spec, "--"+spec.long))
}
if spec.short != "" {
ways = append(ways, synopsis(spec, "-"+spec.short))
}
if len(ways) > 0 {
printTwoCols(w, strings.Join(ways, ", "), spec.help, spec.defaultVal, spec.env)
}
printTwoCols(w, left, spec.help, spec.defaultVal, spec.env)
}
func synopsis(spec *spec, form string) string {

58
usage_test.go
View File

@ -309,3 +309,61 @@ Global options:
p.WriteHelp(&help)
assert.Equal(t, expectedHelp, help.String())
}
func TestUsageWithoutLongNames(t *testing.T) {
expectedHelp := `Usage: example [-a PLACEHOLDER] -b SHORTONLY2
Options:
-a PLACEHOLDER some help [default: some val]
-b SHORTONLY2 some help2
--help, -h display this help and exit
`
var args struct {
ShortOnly string `arg:"-a,--" help:"some help" default:"some val" placeholder:"PLACEHOLDER"`
ShortOnly2 string `arg:"-b,--,required" help:"some help2"`
}
p, err := NewParser(Config{Program: "example"}, &args)
assert.NoError(t, err)
var help bytes.Buffer
p.WriteHelp(&help)
assert.Equal(t, expectedHelp, help.String())
}
func TestUsageWithShortFirst(t *testing.T) {
expectedHelp := `Usage: example [-c CAT] [--dog DOG]
Options:
-c CAT
--dog DOG
--help, -h display this help and exit
`
var args struct {
Dog string
Cat string `arg:"-c,--"`
}
p, err := NewParser(Config{Program: "example"}, &args)
assert.NoError(t, err)
var help bytes.Buffer
p.WriteHelp(&help)
assert.Equal(t, expectedHelp, help.String())
}
func TestUsageWithEnvOptions(t *testing.T) {
expectedHelp := `Usage: example [-s SHORT]
Options:
-s SHORT [env: SHORT]
--help, -h display this help and exit
`
var args struct {
Short string `arg:"--,-s,env"`
EnvOnly string `arg:"--,env"`
EnvOnlyOverriden string `arg:"--,env:CUSTOM"`
}
p, err := NewParser(Config{Program: "example"}, &args)
assert.NoError(t, err)
var help bytes.Buffer
p.WriteHelp(&help)
assert.Equal(t, expectedHelp, help.String())
}