diff options
Diffstat (limited to 'vendor/github.com/spf13/cobra/custom_completions.go')
| -rw-r--r-- | vendor/github.com/spf13/cobra/custom_completions.go | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/vendor/github.com/spf13/cobra/custom_completions.go b/vendor/github.com/spf13/cobra/custom_completions.go new file mode 100644 index 000000000..ba57327c1 --- /dev/null +++ b/vendor/github.com/spf13/cobra/custom_completions.go @@ -0,0 +1,384 @@ +package cobra + +import ( + "errors" + "fmt" + "os" + "strings" + + "github.com/spf13/pflag" +) + +const ( + // ShellCompRequestCmd is the name of the hidden command that is used to request + // completion results from the program. It is used by the shell completion scripts. + ShellCompRequestCmd = "__complete" + // ShellCompNoDescRequestCmd is the name of the hidden command that is used to request + // completion results without their description. It is used by the shell completion scripts. + ShellCompNoDescRequestCmd = "__completeNoDesc" +) + +// Global map of flag completion functions. +var flagCompletionFunctions = map[*pflag.Flag]func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective){} + +// ShellCompDirective is a bit map representing the different behaviors the shell +// can be instructed to have once completions have been provided. +type ShellCompDirective int + +const ( + // ShellCompDirectiveError indicates an error occurred and completions should be ignored. + ShellCompDirectiveError ShellCompDirective = 1 << iota + + // ShellCompDirectiveNoSpace indicates that the shell should not add a space + // after the completion even if there is a single completion provided. + ShellCompDirectiveNoSpace + + // ShellCompDirectiveNoFileComp indicates that the shell should not provide + // file completion even when no completion is provided. + // This currently does not work for zsh or bash < 4 + ShellCompDirectiveNoFileComp + + // ShellCompDirectiveDefault indicates to let the shell perform its default + // behavior after completions have been provided. + ShellCompDirectiveDefault ShellCompDirective = 0 +) + +// RegisterFlagCompletionFunc should be called to register a function to provide completion for a flag. +func (c *Command) RegisterFlagCompletionFunc(flagName string, f func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective)) error { + flag := c.Flag(flagName) + if flag == nil { + return fmt.Errorf("RegisterFlagCompletionFunc: flag '%s' does not exist", flagName) + } + if _, exists := flagCompletionFunctions[flag]; exists { + return fmt.Errorf("RegisterFlagCompletionFunc: flag '%s' already registered", flagName) + } + flagCompletionFunctions[flag] = f + return nil +} + +// Returns a string listing the different directive enabled in the specified parameter +func (d ShellCompDirective) string() string { + var directives []string + if d&ShellCompDirectiveError != 0 { + directives = append(directives, "ShellCompDirectiveError") + } + if d&ShellCompDirectiveNoSpace != 0 { + directives = append(directives, "ShellCompDirectiveNoSpace") + } + if d&ShellCompDirectiveNoFileComp != 0 { + directives = append(directives, "ShellCompDirectiveNoFileComp") + } + if len(directives) == 0 { + directives = append(directives, "ShellCompDirectiveDefault") + } + + if d > ShellCompDirectiveError+ShellCompDirectiveNoSpace+ShellCompDirectiveNoFileComp { + return fmt.Sprintf("ERROR: unexpected ShellCompDirective value: %d", d) + } + return strings.Join(directives, ", ") +} + +// Adds a special hidden command that can be used to request custom completions. +func (c *Command) initCompleteCmd(args []string) { + completeCmd := &Command{ + Use: fmt.Sprintf("%s [command-line]", ShellCompRequestCmd), + Aliases: []string{ShellCompNoDescRequestCmd}, + DisableFlagsInUseLine: true, + Hidden: true, + DisableFlagParsing: true, + Args: MinimumNArgs(1), + Short: "Request shell completion choices for the specified command-line", + Long: fmt.Sprintf("%[2]s is a special command that is used by the shell completion logic\n%[1]s", + "to request completion choices for the specified command-line.", ShellCompRequestCmd), + Run: func(cmd *Command, args []string) { + finalCmd, completions, directive, err := cmd.getCompletions(args) + if err != nil { + CompErrorln(err.Error()) + // Keep going for multiple reasons: + // 1- There could be some valid completions even though there was an error + // 2- Even without completions, we need to print the directive + } + + noDescriptions := (cmd.CalledAs() == ShellCompNoDescRequestCmd) + for _, comp := range completions { + if noDescriptions { + // Remove any description that may be included following a tab character. + comp = strings.Split(comp, "\t")[0] + } + // Print each possible completion to stdout for the completion script to consume. + fmt.Fprintln(finalCmd.OutOrStdout(), comp) + } + + if directive > ShellCompDirectiveError+ShellCompDirectiveNoSpace+ShellCompDirectiveNoFileComp { + directive = ShellCompDirectiveDefault + } + + // As the last printout, print the completion directive for the completion script to parse. + // The directive integer must be that last character following a single colon (:). + // The completion script expects :<directive> + fmt.Fprintf(finalCmd.OutOrStdout(), ":%d\n", directive) + + // Print some helpful info to stderr for the user to understand. + // Output from stderr must be ignored by the completion script. + fmt.Fprintf(finalCmd.ErrOrStderr(), "Completion ended with directive: %s\n", directive.string()) + }, + } + c.AddCommand(completeCmd) + subCmd, _, err := c.Find(args) + if err != nil || subCmd.Name() != ShellCompRequestCmd { + // Only create this special command if it is actually being called. + // This reduces possible side-effects of creating such a command; + // for example, having this command would cause problems to a + // cobra program that only consists of the root command, since this + // command would cause the root command to suddenly have a subcommand. + c.RemoveCommand(completeCmd) + } +} + +func (c *Command) getCompletions(args []string) (*Command, []string, ShellCompDirective, error) { + var completions []string + + // The last argument, which is not completely typed by the user, + // should not be part of the list of arguments + toComplete := args[len(args)-1] + trimmedArgs := args[:len(args)-1] + + // Find the real command for which completion must be performed + finalCmd, finalArgs, err := c.Root().Find(trimmedArgs) + if err != nil { + // Unable to find the real command. E.g., <program> someInvalidCmd <TAB> + return c, completions, ShellCompDirectiveDefault, fmt.Errorf("Unable to find a command for arguments: %v", trimmedArgs) + } + + // When doing completion of a flag name, as soon as an argument starts with + // a '-' we know it is a flag. We cannot use isFlagArg() here as it requires + // the flag to be complete + if len(toComplete) > 0 && toComplete[0] == '-' && !strings.Contains(toComplete, "=") { + // We are completing a flag name + finalCmd.NonInheritedFlags().VisitAll(func(flag *pflag.Flag) { + completions = append(completions, getFlagNameCompletions(flag, toComplete)...) + }) + finalCmd.InheritedFlags().VisitAll(func(flag *pflag.Flag) { + completions = append(completions, getFlagNameCompletions(flag, toComplete)...) + }) + + directive := ShellCompDirectiveDefault + if len(completions) > 0 { + if strings.HasSuffix(completions[0], "=") { + directive = ShellCompDirectiveNoSpace + } + } + return finalCmd, completions, directive, nil + } + + var flag *pflag.Flag + if !finalCmd.DisableFlagParsing { + // We only do flag completion if we are allowed to parse flags + // This is important for commands which have requested to do their own flag completion. + flag, finalArgs, toComplete, err = checkIfFlagCompletion(finalCmd, finalArgs, toComplete) + if err != nil { + // Error while attempting to parse flags + return finalCmd, completions, ShellCompDirectiveDefault, err + } + } + + if flag == nil { + // Complete subcommand names + for _, subCmd := range finalCmd.Commands() { + if subCmd.IsAvailableCommand() && strings.HasPrefix(subCmd.Name(), toComplete) { + completions = append(completions, fmt.Sprintf("%s\t%s", subCmd.Name(), subCmd.Short)) + } + } + + if len(finalCmd.ValidArgs) > 0 { + // Always complete ValidArgs, even if we are completing a subcommand name. + // This is for commands that have both subcommands and ValidArgs. + for _, validArg := range finalCmd.ValidArgs { + if strings.HasPrefix(validArg, toComplete) { + completions = append(completions, validArg) + } + } + + // If there are ValidArgs specified (even if they don't match), we stop completion. + // Only one of ValidArgs or ValidArgsFunction can be used for a single command. + return finalCmd, completions, ShellCompDirectiveNoFileComp, nil + } + + // Always let the logic continue so as to add any ValidArgsFunction completions, + // even if we already found sub-commands. + // This is for commands that have subcommands but also specify a ValidArgsFunction. + } + + // Parse the flags and extract the arguments to prepare for calling the completion function + if err = finalCmd.ParseFlags(finalArgs); err != nil { + return finalCmd, completions, ShellCompDirectiveDefault, fmt.Errorf("Error while parsing flags from args %v: %s", finalArgs, err.Error()) + } + + // We only remove the flags from the arguments if DisableFlagParsing is not set. + // This is important for commands which have requested to do their own flag completion. + if !finalCmd.DisableFlagParsing { + finalArgs = finalCmd.Flags().Args() + } + + // Find the completion function for the flag or command + var completionFn func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective) + if flag != nil { + completionFn = flagCompletionFunctions[flag] + } else { + completionFn = finalCmd.ValidArgsFunction + } + if completionFn == nil { + // Go custom completion not supported/needed for this flag or command + return finalCmd, completions, ShellCompDirectiveDefault, nil + } + + // Call the registered completion function to get the completions + comps, directive := completionFn(finalCmd, finalArgs, toComplete) + completions = append(completions, comps...) + return finalCmd, completions, directive, nil +} + +func getFlagNameCompletions(flag *pflag.Flag, toComplete string) []string { + if nonCompletableFlag(flag) { + return []string{} + } + + var completions []string + flagName := "--" + flag.Name + if strings.HasPrefix(flagName, toComplete) { + // Flag without the = + completions = append(completions, fmt.Sprintf("%s\t%s", flagName, flag.Usage)) + + if len(flag.NoOptDefVal) == 0 { + // Flag requires a value, so it can be suffixed with = + flagName += "=" + completions = append(completions, fmt.Sprintf("%s\t%s", flagName, flag.Usage)) + } + } + + flagName = "-" + flag.Shorthand + if len(flag.Shorthand) > 0 && strings.HasPrefix(flagName, toComplete) { + completions = append(completions, fmt.Sprintf("%s\t%s", flagName, flag.Usage)) + } + + return completions +} + +func checkIfFlagCompletion(finalCmd *Command, args []string, lastArg string) (*pflag.Flag, []string, string, error) { + var flagName string + trimmedArgs := args + flagWithEqual := false + if isFlagArg(lastArg) { + if index := strings.Index(lastArg, "="); index >= 0 { + flagName = strings.TrimLeft(lastArg[:index], "-") + lastArg = lastArg[index+1:] + flagWithEqual = true + } else { + return nil, nil, "", errors.New("Unexpected completion request for flag") + } + } + + if len(flagName) == 0 { + if len(args) > 0 { + prevArg := args[len(args)-1] + if isFlagArg(prevArg) { + // Only consider the case where the flag does not contain an =. + // If the flag contains an = it means it has already been fully processed, + // so we don't need to deal with it here. + if index := strings.Index(prevArg, "="); index < 0 { + flagName = strings.TrimLeft(prevArg, "-") + + // Remove the uncompleted flag or else there could be an error created + // for an invalid value for that flag + trimmedArgs = args[:len(args)-1] + } + } + } + } + + if len(flagName) == 0 { + // Not doing flag completion + return nil, trimmedArgs, lastArg, nil + } + + flag := findFlag(finalCmd, flagName) + if flag == nil { + // Flag not supported by this command, nothing to complete + err := fmt.Errorf("Subcommand '%s' does not support flag '%s'", finalCmd.Name(), flagName) + return nil, nil, "", err + } + + if !flagWithEqual { + if len(flag.NoOptDefVal) != 0 { + // We had assumed dealing with a two-word flag but the flag is a boolean flag. + // In that case, there is no value following it, so we are not really doing flag completion. + // Reset everything to do noun completion. + trimmedArgs = args + flag = nil + } + } + + return flag, trimmedArgs, lastArg, nil +} + +func findFlag(cmd *Command, name string) *pflag.Flag { + flagSet := cmd.Flags() + if len(name) == 1 { + // First convert the short flag into a long flag + // as the cmd.Flag() search only accepts long flags + if short := flagSet.ShorthandLookup(name); short != nil { + name = short.Name + } else { + set := cmd.InheritedFlags() + if short = set.ShorthandLookup(name); short != nil { + name = short.Name + } else { + return nil + } + } + } + return cmd.Flag(name) +} + +// CompDebug prints the specified string to the same file as where the +// completion script prints its logs. +// Note that completion printouts should never be on stdout as they would +// be wrongly interpreted as actual completion choices by the completion script. +func CompDebug(msg string, printToStdErr bool) { + msg = fmt.Sprintf("[Debug] %s", msg) + + // Such logs are only printed when the user has set the environment + // variable BASH_COMP_DEBUG_FILE to the path of some file to be used. + if path := os.Getenv("BASH_COMP_DEBUG_FILE"); path != "" { + f, err := os.OpenFile(path, + os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644) + if err == nil { + defer f.Close() + f.WriteString(msg) + } + } + + if printToStdErr { + // Must print to stderr for this not to be read by the completion script. + fmt.Fprintf(os.Stderr, msg) + } +} + +// CompDebugln prints the specified string with a newline at the end +// to the same file as where the completion script prints its logs. +// Such logs are only printed when the user has set the environment +// variable BASH_COMP_DEBUG_FILE to the path of some file to be used. +func CompDebugln(msg string, printToStdErr bool) { + CompDebug(fmt.Sprintf("%s\n", msg), printToStdErr) +} + +// CompError prints the specified completion message to stderr. +func CompError(msg string) { + msg = fmt.Sprintf("[Error] %s", msg) + CompDebug(msg, true) +} + +// CompErrorln prints the specified completion message to stderr with a newline at the end. +func CompErrorln(msg string) { + CompError(fmt.Sprintf("%s\n", msg)) +} |