Merge pull request #149 from fabianofranz/siblings

Allows command suggestions along with "unknown command" errors
This commit is contained in:
Eric Paris 2015-09-13 22:44:46 -05:00
commit 6d70311770
4 changed files with 116 additions and 1 deletions

View file

@ -418,6 +418,30 @@ func main() {
} }
``` ```
## Suggestions when "unknown command" happens
Cobra will print automatic suggestions when "unknown command" errors happen. This allows Cobra to behavior similarly to the `git` command when a typo happens. For example:
```
$ hugo srever
unknown command "srever" for "hugo"
Did you mean this?
server
Run 'hugo --help' for usage.
```
Suggestions are automatic based on every subcommand registered and use an implementation of Levenshtein distance. Every registered command that matches a minimum distance of 2 (ignoring case) will be displayed as a suggestion.
If you need to disable suggestions or tweak the string distance in your command, use:
command.DisableSuggestions = true
or
command.SuggestionsMinimumDistance = 1
## Generating markdown formatted documentation for your command ## Generating markdown formatted documentation for your command
Cobra can generate a markdown formatted document based on the subcommands, flags, etc. A simple example of how to do this for your command can be found in [Markdown Docs](md_docs.md) Cobra can generate a markdown formatted document based on the subcommands, flags, etc. A simple example of how to do this for your command can be found in [Markdown Docs](md_docs.md)

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@ -132,3 +132,39 @@ func tmpl(w io.Writer, text string, data interface{}) error {
template.Must(t.Parse(text)) template.Must(t.Parse(text))
return t.Execute(w, data) return t.Execute(w, data)
} }
// ld compares two strings and returns the levenshtein distance between them
func ld(s, t string, ignoreCase bool) int {
if ignoreCase {
s = strings.ToLower(s)
t = strings.ToLower(t)
}
d := make([][]int, len(s)+1)
for i := range d {
d[i] = make([]int, len(t)+1)
}
for i := range d {
d[i][0] = i
}
for j := range d[0] {
d[0][j] = j
}
for j := 1; j <= len(t); j++ {
for i := 1; i <= len(s); i++ {
if s[i-1] == t[j-1] {
d[i][j] = d[i-1][j-1]
} else {
min := d[i-1][j]
if d[i][j-1] < min {
min = d[i][j-1]
}
if d[i-1][j-1] < min {
min = d[i-1][j-1]
}
d[i][j] = min + 1
}
}
}
return d[len(s)][len(t)]
}

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@ -799,6 +799,34 @@ func TestRootUnknownCommand(t *testing.T) {
} }
} }
func TestRootSuggestions(t *testing.T) {
outputWithSuggestions := "Error: unknown command \"%s\" for \"cobra-test\"\n\nDid you mean this?\n\t%s\n\nRun 'cobra-test --help' for usage.\n"
outputWithoutSuggestions := "Error: unknown command \"%s\" for \"cobra-test\"\nRun 'cobra-test --help' for usage.\n"
cmd := initializeWithRootCmd()
cmd.AddCommand(cmdTimes)
tests := map[string]string{
"time": "times",
"tiems": "times",
"timeS": "times",
"rimes": "times",
}
for typo, suggestion := range tests {
cmd.DisableSuggestions = false
result := simpleTester(cmd, typo)
if expected := fmt.Sprintf(outputWithSuggestions, typo, suggestion); result.Output != expected {
t.Errorf("Unexpected response.\nExpecting to be:\n %q\nGot:\n %q\n", expected, result.Output)
}
cmd.DisableSuggestions = true
result = simpleTester(cmd, typo)
if expected := fmt.Sprintf(outputWithoutSuggestions, typo); result.Output != expected {
t.Errorf("Unexpected response.\nExpecting to be:\n %q\nGot:\n %q\n", expected, result.Output)
}
}
}
func TestFlagsBeforeCommand(t *testing.T) { func TestFlagsBeforeCommand(t *testing.T) {
// short without space // short without space
x := fullSetupTest("-i10 echo") x := fullSetupTest("-i10 echo")

View file

@ -106,6 +106,11 @@ type Command struct {
helpCommand *Command // The help command helpCommand *Command // The help command
// The global normalization function that we can use on every pFlag set and children commands // The global normalization function that we can use on every pFlag set and children commands
globNormFunc func(f *flag.FlagSet, name string) flag.NormalizedName globNormFunc func(f *flag.FlagSet, name string) flag.NormalizedName
// Disable the suggestions based on Levenshtein distance that go along with 'unknown command' messages
DisableSuggestions bool
// If displaying suggestions, allows to set the minimum levenshtein distance to display, must be > 0
SuggestionsMinimumDistance int
} }
// os.Args[1:] by default, if desired, can be overridden // os.Args[1:] by default, if desired, can be overridden
@ -421,9 +426,31 @@ func (c *Command) Find(args []string) (*Command, []string, error) {
if !commandFound.HasSubCommands() { if !commandFound.HasSubCommands() {
return commandFound, a, nil return commandFound, a, nil
} }
// root command with subcommands, do subcommand checking // root command with subcommands, do subcommand checking
if commandFound == c && len(argsWOflags) > 0 { if commandFound == c && len(argsWOflags) > 0 {
return commandFound, a, fmt.Errorf("unknown command %q for %q", argsWOflags[0], commandFound.CommandPath()) suggestions := ""
if !c.DisableSuggestions {
if c.SuggestionsMinimumDistance <= 0 {
c.SuggestionsMinimumDistance = 2
}
similar := []string{}
for _, cmd := range c.commands {
if cmd.IsAvailableCommand() {
levenshtein := ld(argsWOflags[0], cmd.Name(), true)
if levenshtein <= c.SuggestionsMinimumDistance {
similar = append(similar, cmd.Name())
}
}
}
if len(similar) > 0 {
suggestions += "\n\nDid you mean this?\n"
for _, s := range similar {
suggestions += fmt.Sprintf("\t%v\n", s)
}
}
}
return commandFound, a, fmt.Errorf("unknown command %q for %q%s", argsWOflags[0], commandFound.CommandPath(), suggestions)
} }
return commandFound, a, nil return commandFound, a, nil