Better error message on unrecognized command

Closes issue #1436

License: MIT
Signed-off-by: Shaun Bruce <[email protected]>

commands/cli/cmd_suggestion.go

@@ -0,0 +1,71 @@
+package cli
+
+import (
+ "sort"
+ "strings"
+
+ levenshtein "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/texttheater/golang-levenshtein/levenshtein"
+ cmds "github.com/ipfs/go-ipfs/commands"
+)
+
+// Make a custom slice that can be sorted by its levenshtein value
+type suggestionSlice []*suggestion
+
+type suggestion struct {
+ cmd string
+ levenshtein int
+}
+
+func (s suggestionSlice) Len() int {
+ return len(s)
+}
+
+func (s suggestionSlice) Swap(i, j int) {
+ s[i], s[j] = s[j], s[i]
+}
+
+func (s suggestionSlice) Less(i, j int) bool {
+ return s[i].levenshtein < s[j].levenshtein
+}
+
+func suggestUnknownCmd(args []string, root *cmds.Command) []string {
+ arg := args[0]
+ var suggestions []string
+ sortableSuggestions := make(suggestionSlice, 0)
+ var sFinal []string
+ const MIN_LEVENSHTEIN = 3
+
+ var options levenshtein.Options = levenshtein.Options{
+ InsCost: 1,
+ DelCost: 3,
+ SubCost: 2,
+ Matches: func(sourceCharacter rune, targetCharacter rune) bool {
+ return sourceCharacter == targetCharacter
+ },
+ }
+
+ // Start with a simple strings.Contains check
+ for name, _ := range root.Subcommands {
+ if strings.Contains(arg, name) {
+ suggestions = append(suggestions, name)
+ }
+ }
+
+ // If the string compare returns a match, return
+ if len(suggestions) > 0 {
+ return suggestions
+ }
+
+ for name, _ := range root.Subcommands {
+ lev := levenshtein.DistanceForStrings([]rune(arg), []rune(name), options)
+ if lev <= MIN_LEVENSHTEIN {
+ sortableSuggestions = append(sortableSuggestions, &suggestion{name, lev})
+ }
+ }
+ sort.Sort(sortableSuggestions)
+
+ for _, j := range sortableSuggestions {
+ sFinal = append(sFinal, j.cmd)
+ }
+ return sFinal
+}

commands/cli/parse.go

@@ -41,7 +41,7 @@ func Parse(input []string, stdin *os.File, root *cmds.Command) (cmds.Request, *c
  }
  }
 
- stringArgs, fileArgs, err := parseArgs(stringVals, stdin, cmd.Arguments, recursive)
+ stringArgs, fileArgs, err := parseArgs(stringVals, stdin, cmd.Arguments, recursive, root)
  if err != nil {
  return req, cmd, path, err
  }
@@ -196,7 +196,7 @@ func parseOpts(args []string, root *cmds.Command) (
  return
 }
 
-func parseArgs(inputs []string, stdin *os.File, argDefs []cmds.Argument, recursive bool) ([]string, []files.File, error) {
+func parseArgs(inputs []string, stdin *os.File, argDefs []cmds.Argument, recursive bool, root *cmds.Command) ([]string, []files.File, error) {
  // ignore stdin on Windows
  if runtime.GOOS == "windows" {
  stdin = nil
@@ -231,7 +231,15 @@ func parseArgs(inputs []string, stdin *os.File, argDefs []cmds.Argument, recursi
  // and the last arg definition is not variadic (or there are no definitions), return an error
  notVariadic := len(argDefs) == 0 || !argDefs[len(argDefs)-1].Variadic
  if notVariadic && len(inputs) > len(argDefs) {
- return nil, nil, fmt.Errorf("Expected %v arguments, got %v: %v", len(argDefs), len(inputs), inputs)
+ suggestions := suggestUnknownCmd(inputs, root)
+
+ if len(suggestions) > 1 {
+ return nil, nil, fmt.Errorf("Unknown Command \"%s\"\n\nDid you mean any of these?\n\n\t%s", inputs[0], strings.Join(suggestions, "\n\t"))
+ } else if len(suggestions) > 0 {
+ return nil, nil, fmt.Errorf("Unknown Command \"%s\"\n\nDid you mean this?\n\n\t%s", inputs[0], suggestions[0])
+ } else {
+ return nil, nil, fmt.Errorf("Unknown Command \"%s\"\n", inputs[0])
+ }
  }
 
  stringArgs := make([]string, 0, numInputs)