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Extend Go completions and revamp zsh comp (#1070) (#1070)

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Replace the current Zsh completion with a Zsh completion solution based
on Go completions. This allows to support custom completions (based
on Go completions), but also to standardize the behavior of completion
across all shells.

Also, add support to Go completions for the bash completion annotations:
  BashCompFilenameExt (including Command.MarkFlagFilename() family)
                       - still supported by zsh
  BashCompSubdirsInDir - now supported by zsh
  BashCompOneRequiredFlag (including Command.MarkFlagRequired() family)
                       - now supported by zsh and fish

Finally, remove the suggestin of the = form of flag completion.
The = form is supported, but it will not be suggested to avoid having
duplicated suggestions.
This commit is contained in:
Marc Khouzam 2020-06-29 15:52:14 -04:00 committed by GitHub
parent 04318720db
commit 2c5a0d300f
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GPG Key ID: 4AEE18F83AFDEB23
13 changed files with 2265 additions and 1255 deletions
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14
README.md
View File

@ -28,8 +28,7 @@ name a few. [This list](./projects_using_cobra.md) contains a more extensive lis
* [PreRun and PostRun Hooks](#prerun-and-postrun-hooks)
* [Suggestions when "unknown command" happens](#suggestions-when-unknown-command-happens)
* [Generating documentation for your command](#generating-documentation-for-your-command)
* [Generating bash completions](#generating-bash-completions)
* [Generating zsh completions](#generating-zsh-completions)
* [Generating shell completions](#generating-shell-completions)
- [Contributing](#contributing)
- [License](#license)
@ -50,7 +49,7 @@ Cobra provides:
* Intelligent suggestions (`app srver`... did you mean `app server`?)
* Automatic help generation for commands and flags
* Automatic help flag recognition of `-h`, `--help`, etc.
* Automatically generated bash autocomplete for your application
* Automatically generated shell autocomplete for your application (bash, zsh, fish, powershell)
* Automatically generated man pages for your application
* Command aliases so you can change things without breaking them
* The flexibility to define your own help, usage, etc.
@ -720,14 +719,9 @@ Run 'kubectl help' for usage.
Cobra can generate documentation based on subcommands, flags, etc. Read more about it in the [docs generation documentation](doc/README.md).
## Generating bash completions
## Generating shell completions
Cobra can generate a bash-completion file. If you add more information to your command, these completions can be amazingly powerful and flexible. Read more about it in [Bash Completions](bash_completions.md).
## Generating zsh completions
Cobra can generate zsh-completion file. Read more about it in
[Zsh Completions](zsh_completions.md).
Cobra can generate a shell-completion file for the following shells: Bash, Zsh, Fish, Powershell. If you add more information to your commands, these completions can be amazingly powerful and flexible. Read more about it in [Shell Completions](shell_completions.md).
# Contributing

42
bash_completions.go
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@ -62,6 +62,12 @@ __%[1]s_handle_go_custom_completion()
{
__%[1]s_debug "${FUNCNAME[0]}: cur is ${cur}, words[*] is ${words[*]}, #words[@] is ${#words[@]}"
local shellCompDirectiveError=%[3]d
local shellCompDirectiveNoSpace=%[4]d
local shellCompDirectiveNoFileComp=%[5]d
local shellCompDirectiveFilterFileExt=%[6]d
local shellCompDirectiveFilterDirs=%[7]d
local out requestComp lastParam lastChar comp directive args
# Prepare the command to request completions for the program.
@ -95,24 +101,50 @@ __%[1]s_handle_go_custom_completion()
__%[1]s_debug "${FUNCNAME[0]}: the completion directive is: ${directive}"
__%[1]s_debug "${FUNCNAME[0]}: the completions are: ${out[*]}"
if [ $((directive & %[3]d)) -ne 0 ]; then
if [ $((directive & shellCompDirectiveError)) -ne 0 ]; then
# Error code. No completion.
__%[1]s_debug "${FUNCNAME[0]}: received error from custom completion go code"
return
else
if [ $((directive & %[4]d)) -ne 0 ]; then
if [ $((directive & shellCompDirectiveNoSpace)) -ne 0 ]; then
if [[ $(type -t compopt) = "builtin" ]]; then
__%[1]s_debug "${FUNCNAME[0]}: activating no space"
compopt -o nospace
fi
fi
if [ $((directive & %[5]d)) -ne 0 ]; then
if [ $((directive & shellCompDirectiveNoFileComp)) -ne 0 ]; then
if [[ $(type -t compopt) = "builtin" ]]; then
__%[1]s_debug "${FUNCNAME[0]}: activating no file completion"
compopt +o default
fi
fi
fi
if [ $((directive & shellCompDirectiveFilterFileExt)) -ne 0 ]; then
# File extension filtering
local fullFilter filter filteringCmd
# Do not use quotes around the $out variable or else newline
# characters will be kept.
for filter in ${out[*]}; do
fullFilter+="$filter|"
done
filteringCmd="_filedir $fullFilter"
__%[1]s_debug "File filtering command: $filteringCmd"
$filteringCmd
elif [ $((directive & shellCompDirectiveFilterDirs)) -ne 0 ]; then
# File completion for directories only
local subDir
# Use printf to strip any trailing newline
subdir=$(printf "%%s" "${out[0]}")
if [ -n "$subdir" ]; then
__%[1]s_debug "Listing directories in $subdir"
__%[1]s_handle_subdirs_in_dir_flag "$subdir"
else
__%[1]s_debug "Listing directories in ."
_filedir -d
fi
else
while IFS='' read -r comp; do
COMPREPLY+=("$comp")
done < <(compgen -W "${out[*]}" -- "$cur")
@ -343,7 +375,9 @@ __%[1]s_handle_word()
__%[1]s_handle_word
}
`, name, ShellCompNoDescRequestCmd, ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp))
`, name, ShellCompNoDescRequestCmd,
ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp,
ShellCompDirectiveFilterFileExt, ShellCompDirectiveFilterDirs))
}
func writePostscript(buf *bytes.Buffer, name string) {

306
bash_completions.md
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@ -1,206 +1,14 @@
# Generating Bash Completions For Your Own cobra.Command
# Generating Bash Completions For Your cobra.Command
If you are using the generator you can create a completion command by running
Please refer to [Shell Completions](shell_completions.md) for details.
```bash
cobra add completion
```
## Bash legacy dynamic completions
Update the help text show how to install the bash_completion Linux show here [Kubectl docs show mac options](https://kubernetes.io/docs/tasks/tools/install-kubectl/#enabling-shell-autocompletion)
For backwards-compatibility, Cobra still supports its legacy dynamic completion solution (described below). Unlike the `ValidArgsFunction` solution, the legacy solution will only work for Bash shell-completion and not for other shells. This legacy solution can be used along-side `ValidArgsFunction` and `RegisterFlagCompletionFunc()`, as long as both solutions are not used for the same command. This provides a path to gradually migrate from the legacy solution to the new solution.
Writing the shell script to stdout allows the most flexible use.
The legacy solution allows you to inject bash functions into the bash completion script. Those bash functions are responsible for providing the completion choices for your own completions.
```go
// completionCmd represents the completion command
var completionCmd = &cobra.Command{
Use: "completion",
Short: "Generates bash completion scripts",
Long: `To load completion run
. <(bitbucket completion)
To configure your bash shell to load completions for each session add to your bashrc
# ~/.bashrc or ~/.profile
. <(bitbucket completion)
`,
Run: func(cmd *cobra.Command, args []string) {
rootCmd.GenBashCompletion(os.Stdout);
},
}
```
**Note:** The cobra generator may include messages printed to stdout for example if the config file is loaded, this will break the auto complete script
## Example from kubectl
Generating bash completions from a cobra command is incredibly easy. An actual program which does so for the kubernetes kubectl binary is as follows:
```go
package main
import (
"io/ioutil"
"os"
"k8s.io/kubernetes/pkg/kubectl/cmd"
"k8s.io/kubernetes/pkg/kubectl/cmd/util"
)
func main() {
kubectl := cmd.NewKubectlCommand(util.NewFactory(nil), os.Stdin, ioutil.Discard, ioutil.Discard)
kubectl.GenBashCompletionFile("out.sh")
}
```
`out.sh` will get you completions of subcommands and flags. Copy it to `/etc/bash_completion.d/` as described [here](https://debian-administration.org/article/316/An_introduction_to_bash_completion_part_1) and reset your terminal to use autocompletion. If you make additional annotations to your code, you can get even more intelligent and flexible behavior.
## Have the completions code complete your 'nouns'
### Static completion of nouns
This method allows you to provide a pre-defined list of completion choices for your nouns using the `validArgs` field.
For example, if you want `kubectl get [tab][tab]` to show a list of valid "nouns" you have to set them. Simplified code from `kubectl get` looks like:
```go
validArgs []string = { "pod", "node", "service", "replicationcontroller" }
cmd := &cobra.Command{
Use: "get [(-o|--output=)json|yaml|template|...] (RESOURCE [NAME] | RESOURCE/NAME ...)",
Short: "Display one or many resources",
Long: get_long,
Example: get_example,
Run: func(cmd *cobra.Command, args []string) {
err := RunGet(f, out, cmd, args)
util.CheckErr(err)
},
ValidArgs: validArgs,
}
```
Notice we put the "ValidArgs" on the "get" subcommand. Doing so will give results like
```bash
# kubectl get [tab][tab]
node pod replicationcontroller service
```
### Plural form and shortcuts for nouns
If your nouns have a number of aliases, you can define them alongside `ValidArgs` using `ArgAliases`:
```go
argAliases []string = { "pods", "nodes", "services", "svc", "replicationcontrollers", "rc" }
cmd := &cobra.Command{
...
ValidArgs: validArgs,
ArgAliases: argAliases
}
```
The aliases are not shown to the user on tab completion, but they are accepted as valid nouns by
the completion algorithm if entered manually, e.g. in:
```bash
# kubectl get rc [tab][tab]
backend frontend database
```
Note that without declaring `rc` as an alias, the completion algorithm would show the list of nouns
in this example again instead of the replication controllers.
### Dynamic completion of nouns
In some cases it is not possible to provide a list of possible completions in advance. Instead, the list of completions must be determined at execution-time. Cobra provides two ways of defining such dynamic completion of nouns. Note that both these methods can be used along-side each other as long as they are not both used for the same command.
**Note**: *Custom Completions written in Go* will automatically work for other shell-completion scripts (e.g., Fish shell), while *Custom Completions written in Bash* will only work for Bash shell-completion. It is therefore recommended to use *Custom Completions written in Go*.
#### 1. Custom completions of nouns written in Go
In a similar fashion as for static completions, you can use the `ValidArgsFunction` field to provide a Go function that Cobra will execute when it needs the list of completion choices for the nouns of a command. Note that either `ValidArgs` or `ValidArgsFunction` can be used for a single cobra command, but not both.
Simplified code from `helm status` looks like:
```go
cmd := &cobra.Command{
Use: "status RELEASE_NAME",
Short: "Display the status of the named release",
Long: status_long,
RunE: func(cmd *cobra.Command, args []string) {
RunGet(args[0])
},
ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
if len(args) != 0 {
return nil, cobra.ShellCompDirectiveNoFileComp
}
return getReleasesFromCluster(toComplete), cobra.ShellCompDirectiveNoFileComp
},
}
```
Where `getReleasesFromCluster()` is a Go function that obtains the list of current Helm releases running on the Kubernetes cluster.
Notice we put the `ValidArgsFunction` on the `status` subcommand. Let's assume the Helm releases on the cluster are: `harbor`, `notary`, `rook` and `thanos` then this dynamic completion will give results like
```bash
# helm status [tab][tab]
harbor notary rook thanos
```
You may have noticed the use of `cobra.ShellCompDirective`. These directives are bit fields allowing to control some shell completion behaviors for your particular completion. You can combine them with the bit-or operator such as `cobra.ShellCompDirectiveNoSpace | cobra.ShellCompDirectiveNoFileComp`
```go
// Indicates an error occurred and completions should be ignored.
ShellCompDirectiveError
// Indicates that the shell should not add a space after the completion,
// even if there is a single completion provided.
ShellCompDirectiveNoSpace
// 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
// Indicates that the shell will perform its default behavior after completions
// have been provided (this implies !ShellCompDirectiveNoSpace && !ShellCompDirectiveNoFileComp).
ShellCompDirectiveDefault
```
When using the `ValidArgsFunction`, Cobra will call your registered function after having parsed all flags and arguments provided in the command-line. You therefore don't need to do this parsing yourself. For example, when a user calls `helm status --namespace my-rook-ns [tab][tab]`, Cobra will call your registered `ValidArgsFunction` after having parsed the `--namespace` flag, as it would have done when calling the `RunE` function.
##### Debugging
Cobra achieves dynamic completions written in Go through the use of a hidden command called by the completion script. To debug your Go completion code, you can call this hidden command directly:
```bash
# helm __complete status har<ENTER>
harbor
:4
Completion ended with directive: ShellCompDirectiveNoFileComp # This is on stderr
```
***Important:*** If the noun to complete is empty, you must pass an empty parameter to the `__complete` command:
```bash
# helm __complete status ""<ENTER>
harbor
notary
rook
thanos
:4
Completion ended with directive: ShellCompDirectiveNoFileComp # This is on stderr
```
Calling the `__complete` command directly allows you to run the Go debugger to troubleshoot your code. You can also add printouts to your code; Cobra provides the following functions to use for printouts in Go completion code:
```go
// Prints to the completion script debug file (if BASH_COMP_DEBUG_FILE
// is set to a file path) and optionally prints to stderr.
cobra.CompDebug(msg string, printToStdErr bool) {
cobra.CompDebugln(msg string, printToStdErr bool)
// Prints to the completion script debug file (if BASH_COMP_DEBUG_FILE
// is set to a file path) and to stderr.
cobra.CompError(msg string)
cobra.CompErrorln(msg string)
```
***Important:*** You should **not** leave traces that print to stdout in your completion code as they will be interpreted as completion choices by the completion script. Instead, use the cobra-provided debugging traces functions mentioned above.
#### 2. Custom completions of nouns written in Bash
This method allows you to inject bash functions into the completion script. Those bash functions are responsible for providing the completion choices for your own completions.
Some more actual code that works in kubernetes:
Some code that works in kubernetes:
```bash
const (
@ -253,93 +61,7 @@ Find more information at https://github.com/GoogleCloudPlatform/kubernetes.`,
The `BashCompletionFunction` option is really only valid/useful on the root command. Doing the above will cause `__kubectl_custom_func()` (`__<command-use>_custom_func()`) to be called when the built in processor was unable to find a solution. In the case of kubernetes a valid command might look something like `kubectl get pod [mypod]`. If you type `kubectl get pod [tab][tab]` the `__kubectl_customc_func()` will run because the cobra.Command only understood "kubectl" and "get." `__kubectl_custom_func()` will see that the cobra.Command is "kubectl_get" and will thus call another helper `__kubectl_get_resource()`. `__kubectl_get_resource` will look at the 'nouns' collected. In our example the only noun will be `pod`. So it will call `__kubectl_parse_get pod`. `__kubectl_parse_get` will actually call out to kubernetes and get any pods. It will then set `COMPREPLY` to valid pods!
## Mark flags as required
Most of the time completions will only show subcommands. But if a flag is required to make a subcommand work, you probably want it to show up when the user types [tab][tab]. Marking a flag as 'Required' is incredibly easy.
```go
cmd.MarkFlagRequired("pod")
cmd.MarkFlagRequired("container")
```
and you'll get something like
```bash
# kubectl exec [tab][tab][tab]
-c --container= -p --pod=
```
# Specify valid filename extensions for flags that take a filename
In this example we use --filename= and expect to get a json or yaml file as the argument. To make this easier we annotate the --filename flag with valid filename extensions.
```go
annotations := []string{"json", "yaml", "yml"}
annotation := make(map[string][]string)
annotation[cobra.BashCompFilenameExt] = annotations
flag := &pflag.Flag{
Name: "filename",
Shorthand: "f",
Usage: usage,
Value: value,
DefValue: value.String(),
Annotations: annotation,
}
cmd.Flags().AddFlag(flag)
```
Now when you run a command with this filename flag you'll get something like
```bash
# kubectl create -f
test/ example/ rpmbuild/
hello.yml test.json
```
So while there are many other files in the CWD it only shows me subdirs and those with valid extensions.
# Specify custom flag completion
As for nouns, Cobra provides two ways of defining dynamic completion of flags. Note that both these methods can be used along-side each other as long as they are not both used for the same flag.
**Note**: *Custom Completions written in Go* will automatically work for other shell-completion scripts (e.g., Fish shell), while *Custom Completions written in Bash* will only work for Bash shell-completion. It is therefore recommended to use *Custom Completions written in Go*.
## 1. Custom completions of flags written in Go
To provide a Go function that Cobra will execute when it needs the list of completion choices for a flag, you must register the function in the following manner:
```go
flagName := "output"
cmd.RegisterFlagCompletionFunc(flagName, func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
return []string{"json", "table", "yaml"}, cobra.ShellCompDirectiveDefault
})
```
Notice that calling `RegisterFlagCompletionFunc()` is done through the `command` with which the flag is associated. In our example this dynamic completion will give results like so:
```bash
# helm status --output [tab][tab]
json table yaml
```
### Debugging
You can also easily debug your Go completion code for flags:
```bash
# helm __complete status --output ""
json
table
yaml
:4
Completion ended with directive: ShellCompDirectiveNoFileComp # This is on stderr
```
***Important:*** You should **not** leave traces that print to stdout in your completion code as they will be interpreted as completion choices by the completion script. Instead, use the cobra-provided debugging traces functions mentioned in the above section.
## 2. Custom completions of flags written in Bash
Alternatively, you can use bash code for flag custom completion. Similar to the filename
completion and filtering using `cobra.BashCompFilenameExt`, you can specify
a custom flag completion bash function with `cobra.BashCompCustom`:
Similarly, for flags:
```go
annotation := make(map[string][]string)
@ -367,17 +89,3 @@ __kubectl_get_namespaces()
fi
}
```
# Using bash aliases for commands
You can also configure the `bash aliases` for the commands and they will also support completions.
```bash
alias aliasname=origcommand
complete -o default -F __start_origcommand aliasname
# and now when you run `aliasname` completion will make
# suggestions as it did for `origcommand`.
$) aliasname <tab><tab>
completion firstcommand secondcommand
```

307
custom_completions.go
View File

@ -1,7 +1,6 @@
package cobra
import (
"errors"
"fmt"
"os"
"strings"
@ -38,8 +37,29 @@ const (
// This currently does not work for zsh or bash < 4
ShellCompDirectiveNoFileComp
// ShellCompDirectiveFilterFileExt indicates that the provided completions
// should be used as file extension filters.
// For flags, using Command.MarkFlagFilename() and Command.MarkPersistentFlagFilename()
// is a shortcut to using this directive explicitly. The BashCompFilenameExt
// annotation can also be used to obtain the same behavior for flags.
ShellCompDirectiveFilterFileExt
// ShellCompDirectiveFilterDirs indicates that only directory names should
// be provided in file completion. To request directory names within another
// directory, the returned completions should specify the directory within
// which to search. The BashCompSubdirsInDir annotation can be used to
// obtain the same behavior but only for flags.
ShellCompDirectiveFilterDirs
// ===========================================================================
// All directives using iota should be above this one.
// For internal use.
shellCompDirectiveMaxValue
// ShellCompDirectiveDefault indicates to let the shell perform its default
// behavior after completions have been provided.
// This one must be last to avoid messing up the iota count.
ShellCompDirectiveDefault ShellCompDirective = 0
)
@ -68,11 +88,17 @@ func (d ShellCompDirective) string() string {
if d&ShellCompDirectiveNoFileComp != 0 {
directives = append(directives, "ShellCompDirectiveNoFileComp")
}
if d&ShellCompDirectiveFilterFileExt != 0 {
directives = append(directives, "ShellCompDirectiveFilterFileExt")
}
if d&ShellCompDirectiveFilterDirs != 0 {
directives = append(directives, "ShellCompDirectiveFilterDirs")
}
if len(directives) == 0 {
directives = append(directives, "ShellCompDirectiveDefault")
}
if d > ShellCompDirectiveError+ShellCompDirectiveNoSpace+ShellCompDirectiveNoFileComp {
if d >= shellCompDirectiveMaxValue {
return fmt.Sprintf("ERROR: unexpected ShellCompDirective value: %d", d)
}
return strings.Join(directives, ", ")
@ -105,11 +131,19 @@ func (c *Command) initCompleteCmd(args []string) {
// Remove any description that may be included following a tab character.
comp = strings.Split(comp, "\t")[0]
}
// Finally trim the completion. This is especially important to get rid
// of a trailing tab when there are no description following it.
// For example, a sub-command without a description should not be completed
// with a tab at the end (or else zsh will show a -- following it
// although there is no description).
comp = strings.TrimSpace(comp)
// Print each possible completion to stdout for the completion script to consume.
fmt.Fprintln(finalCmd.OutOrStdout(), comp)
}
if directive > ShellCompDirectiveError+ShellCompDirectiveNoSpace+ShellCompDirectiveNoFileComp {
if directive >= shellCompDirectiveMaxValue {
directive = ShellCompDirectiveDefault
}
@ -136,8 +170,6 @@ func (c *Command) initCompleteCmd(args []string) {
}
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]
@ -147,81 +179,158 @@ func (c *Command) getCompletions(args []string) (*Command, []string, ShellCompDi
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)
return c, []string{}, ShellCompDirectiveDefault, fmt.Errorf("Unable to find a command for arguments: %v", trimmedArgs)
}
// Check if we are doing flag value completion before parsing the flags.
// This is important because if we are completing a flag value, we need to also
// remove the flag name argument from the list of finalArgs or else the parsing
// could fail due to an invalid value (incomplete) for the flag.
flag, finalArgs, toComplete, err := checkIfFlagCompletion(finalCmd, finalArgs, toComplete)
if err != nil {
// Error while attempting to parse flags
return finalCmd, []string{}, ShellCompDirectiveDefault, err
}
// Parse the flags early so we can check if required flags are set
if err = finalCmd.ParseFlags(finalArgs); err != nil {
return finalCmd, []string{}, ShellCompDirectiveDefault, fmt.Errorf("Error while parsing flags from args %v: %s", finalArgs, err.Error())
}
if flag != nil {
// Check if we are completing a flag value subject to annotations
if validExts, present := flag.Annotations[BashCompFilenameExt]; present {
if len(validExts) != 0 {
// File completion filtered by extensions
return finalCmd, validExts, ShellCompDirectiveFilterFileExt, nil
}
// The annotation requests simple file completion. There is no reason to do
// that since it is the default behavior anyway. Let's ignore this annotation
// in case the program also registered a completion function for this flag.
// Even though it is a mistake on the program's side, let's be nice when we can.
}
if subDir, present := flag.Annotations[BashCompSubdirsInDir]; present {
if len(subDir) == 1 {
// Directory completion from within a directory
return finalCmd, subDir, ShellCompDirectiveFilterDirs, nil
}
// Directory completion
return finalCmd, []string{}, ShellCompDirectiveFilterDirs, nil
}
}
// 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)...)
})
// the flag name to be complete
if flag == nil && len(toComplete) > 0 && toComplete[0] == '-' && !strings.Contains(toComplete, "=") {
var completions []string
directive := ShellCompDirectiveDefault
if len(completions) > 0 {
if strings.HasSuffix(completions[0], "=") {
directive = ShellCompDirectiveNoSpace
// First check for required flags
completions = completeRequireFlags(finalCmd, toComplete)
// If we have not found any required flags, only then can we show regular flags
if len(completions) == 0 {
doCompleteFlags := func(flag *pflag.Flag) {
if !flag.Changed ||
strings.Contains(flag.Value.Type(), "Slice") ||
strings.Contains(flag.Value.Type(), "Array") {
// If the flag is not already present, or if it can be specified multiple times (Array or Slice)
// we suggest it as a completion
completions = append(completions, getFlagNameCompletions(flag, toComplete)...)
}
}
// We cannot use finalCmd.Flags() because we may not have called ParsedFlags() for commands
// that have set DisableFlagParsing; it is ParseFlags() that merges the inherited and
// non-inherited flags.
finalCmd.InheritedFlags().VisitAll(func(flag *pflag.Flag) {
doCompleteFlags(flag)
})
finalCmd.NonInheritedFlags().VisitAll(func(flag *pflag.Flag) {
doCompleteFlags(flag)
})
}
directive := ShellCompDirectiveNoFileComp
if len(completions) == 1 && strings.HasSuffix(completions[0], "=") {
// If there is a single completion, the shell usually adds a space
// after the completion. We don't want that if the flag ends with an =
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, including the help command
for _, subCmd := range finalCmd.Commands() {
if subCmd.IsAvailableCommand() || subCmd == finalCmd.helpCommand {
if 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()
}
var completions []string
directive := ShellCompDirectiveDefault
if flag == nil {
// Check if there are any local, non-persistent flags on the command-line
foundLocalNonPersistentFlag := false
localNonPersistentFlags := finalCmd.LocalNonPersistentFlags()
finalCmd.NonInheritedFlags().VisitAll(func(flag *pflag.Flag) {
if localNonPersistentFlags.Lookup(flag.Name) != nil && flag.Changed {
foundLocalNonPersistentFlag = true
}
})
// Complete subcommand names, including the help command
if len(finalArgs) == 0 && !foundLocalNonPersistentFlag {
// We only complete sub-commands if:
// - there are no arguments on the command-line and
// - there are no local, non-peristent flag on the command-line
for _, subCmd := range finalCmd.Commands() {
if subCmd.IsAvailableCommand() || subCmd == finalCmd.helpCommand {
if strings.HasPrefix(subCmd.Name(), toComplete) {
completions = append(completions, fmt.Sprintf("%s\t%s", subCmd.Name(), subCmd.Short))
}
directive = ShellCompDirectiveNoFileComp
}
}
}
// Complete required flags even without the '-' prefix
completions = append(completions, completeRequireFlags(finalCmd, toComplete)...)
// Always complete ValidArgs, even if we are completing a subcommand name.
// This is for commands that have both subcommands and ValidArgs.
if len(finalCmd.ValidArgs) > 0 {
if len(finalArgs) == 0 {
// ValidArgs are only for the first argument
for _, validArg := range finalCmd.ValidArgs {
if strings.HasPrefix(validArg, toComplete) {
completions = append(completions, validArg)
}
}
directive = ShellCompDirectiveNoFileComp
// If no completions were found within commands or ValidArgs,
// see if there are any ArgAliases that should be completed.
if len(completions) == 0 {
for _, argAlias := range finalCmd.ArgAliases {
if strings.HasPrefix(argAlias, toComplete) {
completions = append(completions, argAlias)
}
}
}
}
// 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, directive, nil
}
// 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.
}
// Find the completion function for the flag or command
var completionFn func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective)
if flag != nil {
@ -229,14 +338,14 @@ func (c *Command) getCompletions(args []string) (*Command, []string, ShellCompDi
} else {
completionFn = finalCmd.ValidArgsFunction
}
if completionFn == nil {
// Go custom completion not supported/needed for this flag or command
return finalCmd, completions, ShellCompDirectiveDefault, nil
if completionFn != nil {
// Go custom completion defined for this flag or command.
// Call the registered completion function to get the completions.
var comps []string
comps, directive = completionFn(finalCmd, finalArgs, toComplete)
completions = append(completions, comps...)
}
// Call the registered completion function to get the completions
comps, directive := completionFn(finalCmd, finalArgs, toComplete)
completions = append(completions, comps...)
return finalCmd, completions, directive, nil
}
@ -251,11 +360,18 @@ func getFlagNameCompletions(flag *pflag.Flag, toComplete string) []string {
// 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))
}
// Why suggest both long forms: --flag and --flag= ?
// This forces the user to *always* have to type either an = or a space after the flag name.
// Let's be nice and avoid making users have to do that.
// Since boolean flags and shortname flags don't show the = form, let's go that route and never show it.
// The = form will still work, we just won't suggest it.
// This also makes the list of suggested flags shorter as we avoid all the = forms.
//
// 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
@ -266,17 +382,54 @@ func getFlagNameCompletions(flag *pflag.Flag, toComplete string) []string {
return completions
}
func completeRequireFlags(finalCmd *Command, toComplete string) []string {
var completions []string
doCompleteRequiredFlags := func(flag *pflag.Flag) {
if _, present := flag.Annotations[BashCompOneRequiredFlag]; present {
if !flag.Changed {
// If the flag is not already present, we suggest it as a completion
completions = append(completions, getFlagNameCompletions(flag, toComplete)...)
}
}
}
// We cannot use finalCmd.Flags() because we may not have called ParsedFlags() for commands
// that have set DisableFlagParsing; it is ParseFlags() that merges the inherited and
// non-inherited flags.
finalCmd.InheritedFlags().VisitAll(func(flag *pflag.Flag) {
doCompleteRequiredFlags(flag)
})
finalCmd.NonInheritedFlags().VisitAll(func(flag *pflag.Flag) {
doCompleteRequiredFlags(flag)
})
return completions
}
func checkIfFlagCompletion(finalCmd *Command, args []string, lastArg string) (*pflag.Flag, []string, string, error) {
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.
return nil, args, lastArg, nil
}
var flagName string
trimmedArgs := args
flagWithEqual := false
if isFlagArg(lastArg) {
// 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 that function
// requires the flag name to be complete
if len(lastArg) > 0 && lastArg[0] == '-' {
if index := strings.Index(lastArg, "="); index >= 0 {
// Flag with an =
flagName = strings.TrimLeft(lastArg[:index], "-")
lastArg = lastArg[index+1:]
flagWithEqual = true
} else {
return nil, nil, "", errors.New("Unexpected completion request for flag")
// Normal flag completion
return nil, args, lastArg, nil
}
}

1238
custom_completions_test.go
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File diff suppressed because it is too large Load Diff

48
fish_completions.go
View File

@ -37,6 +37,12 @@ function __%[1]s_perform_completion
end
__%[1]s_debug "emptyArg: $emptyArg"
if not type -q "$args[1]"
# This can happen when "complete --do-complete %[1]s" is called when running this script.
__%[1]s_debug "Cannot find $args[1]. No completions."
return
end
set requestComp "$args[1] %[2]s $args[2..-1] $emptyArg"
__%[1]s_debug "Calling $requestComp"
@ -71,7 +77,8 @@ function __%[1]s_prepare_completions
# Check if the command-line is already provided. This is useful for testing.
if not set --query __%[1]s_comp_commandLine
set __%[1]s_comp_commandLine (commandline)
# Use the -c flag to allow for completion in the middle of the line
set __%[1]s_comp_commandLine (commandline -c)
end
__%[1]s_debug "commandLine is: $__%[1]s_comp_commandLine"
@ -83,7 +90,7 @@ function __%[1]s_prepare_completions
__%[1]s_debug "No completion, probably due to a failure"
# Might as well do file completion, in case it helps
set --global __%[1]s_comp_do_file_comp 1
return 0
return 1
end
set directive (string sub --start 2 $results[-1])
@ -92,20 +99,35 @@ function __%[1]s_prepare_completions
__%[1]s_debug "Completions are: $__%[1]s_comp_results"
__%[1]s_debug "Directive is: $directive"
set shellCompDirectiveError %[3]d
set shellCompDirectiveNoSpace %[4]d
set shellCompDirectiveNoFileComp %[5]d
set shellCompDirectiveFilterFileExt %[6]d
set shellCompDirectiveFilterDirs %[7]d
if test -z "$directive"
set directive 0
end
set compErr (math (math --scale 0 $directive / %[3]d) %% 2)
set compErr (math (math --scale 0 $directive / $shellCompDirectiveError) %% 2)
if test $compErr -eq 1
__%[1]s_debug "Received error directive: aborting."
# Might as well do file completion, in case it helps
set --global __%[1]s_comp_do_file_comp 1
return 0
return 1
end
set nospace (math (math --scale 0 $directive / %[4]d) %% 2)
set nofiles (math (math --scale 0 $directive / %[5]d) %% 2)
set filefilter (math (math --scale 0 $directive / $shellCompDirectiveFilterFileExt) %% 2)
set dirfilter (math (math --scale 0 $directive / $shellCompDirectiveFilterDirs) %% 2)
if test $filefilter -eq 1; or test $dirfilter -eq 1
__%[1]s_debug "File extension filtering or directory filtering not supported"
# Do full file completion instead
set --global __%[1]s_comp_do_file_comp 1
return 1
end
set nospace (math (math --scale 0 $directive / $shellCompDirectiveNoSpace) %% 2)
set nofiles (math (math --scale 0 $directive / $shellCompDirectiveNoFileComp) %% 2)
__%[1]s_debug "nospace: $nospace, nofiles: $nofiles"
@ -132,9 +154,13 @@ function __%[1]s_prepare_completions
return (not set --query __%[1]s_comp_do_file_comp)
end
# Remove any pre-existing completions for the program since we will be handling all of them
# TODO this cleanup is not sufficient. Fish completions are only loaded once the user triggers
# them, so the below deletion will not work as it is run too early. What else can we do?
# Since Fish completions are only loaded once the user triggers them, we trigger them ourselves
# so we can properly delete any completions provided by another script.
# The space after the the program name is essential to trigger completion for the program
# and not completion of the program name itself.
complete --do-complete "%[1]s " &> /dev/null
# Remove any pre-existing completions for the program since we will be handling all of them.
complete -c %[1]s -e
# The order in which the below two lines are defined is very important so that __%[1]s_prepare_completions
@ -149,7 +175,9 @@ complete -c %[1]s -n 'set --query __%[1]s_comp_do_file_comp'
# It provides the program's completion choices.
complete -c %[1]s -n '__%[1]s_prepare_completions' -f -a '$__%[1]s_comp_results'
`, name, compCmd, ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp))
`, name, compCmd,
ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp,
ShellCompDirectiveFilterFileExt, ShellCompDirectiveFilterDirs))
}
// GenFishCompletion generates fish completion file and writes to the passed writer.

7
fish_completions.md
View File

@ -1,7 +1,4 @@
## Generating Fish Completions for your own cobra.Command
## Generating Fish Completions For Your cobra.Command
Cobra supports native Fish completions generated from the root `cobra.Command`. You can use the `command.GenFishCompletion()` or `command.GenFishCompletionFile()` functions. You must provide these functions with a parameter indicating if the completions should be annotated with a description; Cobra will provide the description automatically based on usage information. You can choose to make this option configurable by your users.
Please refer to [Shell Completions](shell_completions.md) for details.
### Limitations
* Custom completions implemented using the `ValidArgsFunction` and `RegisterFlagCompletionFunc()` are supported automatically but the ones implemented in Bash scripting are not.

2
powershell_completions.md
View File

@ -2,6 +2,8 @@
Cobra can generate PowerShell completion scripts. Users need PowerShell version 5.0 or above, which comes with Windows 10 and can be downloaded separately for Windows 7 or 8.1. They can then write the completions to a file and source this file from their PowerShell profile, which is referenced by the `$Profile` environment variable. See `Get-Help about_Profiles` for more info about PowerShell profiles.
*Note*: PowerShell completions have not (yet?) been aligned to Cobra's generic shell completion support. This implies the PowerShell completions are not as rich as for other shells (see [What's not yet supported](#whats-not-yet-supported)), and may behave slightly differently. They are still very useful for PowerShell users.
# What's supported
- Completion for subcommands using their `.Short` description

53
shell_completions.go
View File

@ -4,82 +4,81 @@ import (
"github.com/spf13/pflag"
)
// MarkFlagRequired adds the BashCompOneRequiredFlag annotation to the named flag if it exists,
// MarkFlagRequired instructs the various shell completion implementations to
// prioritize the named flag when performing completion,
// and causes your command to report an error if invoked without the flag.
func (c *Command) MarkFlagRequired(name string) error {
return MarkFlagRequired(c.Flags(), name)
}
// MarkPersistentFlagRequired adds the BashCompOneRequiredFlag annotation to the named persistent flag if it exists,
// MarkPersistentFlagRequired instructs the various shell completion implementations to
// prioritize the named persistent flag when performing completion,
// and causes your command to report an error if invoked without the flag.
func (c *Command) MarkPersistentFlagRequired(name string) error {
return MarkFlagRequired(c.PersistentFlags(), name)
}
// MarkFlagRequired adds the BashCompOneRequiredFlag annotation to the named flag if it exists,
// MarkFlagRequired instructs the various shell completion implementations to
// prioritize the named flag when performing completion,
// and causes your command to report an error if invoked without the flag.
func MarkFlagRequired(flags *pflag.FlagSet, name string) error {
return flags.SetAnnotation(name, BashCompOneRequiredFlag, []string{"true"})
}
// MarkFlagFilename adds the BashCompFilenameExt annotation to the named flag, if it exists.
// Generated bash autocompletion will select filenames for the flag, limiting to named extensions if provided.
// MarkFlagFilename instructs the various shell completion implementations to
// limit completions for the named flag to the specified file extensions.
func (c *Command) MarkFlagFilename(name string, extensions ...string) error {
return MarkFlagFilename(c.Flags(), name, extensions...)
}
// MarkFlagCustom adds the BashCompCustom annotation to the named flag, if it exists.
// Generated bash autocompletion will call the bash function f for the flag.
// The bash completion script will call the bash function f for the flag.
//
// This will only work for bash completion.
// It is recommended to instead use c.RegisterFlagCompletionFunc(...) which allows
// to register a Go function which will work across all shells.
func (c *Command) MarkFlagCustom(name string, f string) error {
return MarkFlagCustom(c.Flags(), name, f)
}
// MarkPersistentFlagFilename instructs the various shell completion
// implementations to limit completions for this persistent flag to the
// specified extensions (patterns).
//
// Shell Completion compatibility matrix: bash, zsh
// implementations to limit completions for the named persistent flag to the
// specified file extensions.
func (c *Command) MarkPersistentFlagFilename(name string, extensions ...string) error {
return MarkFlagFilename(c.PersistentFlags(), name, extensions...)
}
// MarkFlagFilename instructs the various shell completion implementations to
// limit completions for this flag to the specified extensions (patterns).
//
// Shell Completion compatibility matrix: bash, zsh
// limit completions for the named flag to the specified file extensions.
func MarkFlagFilename(flags *pflag.FlagSet, name string, extensions ...string) error {
return flags.SetAnnotation(name, BashCompFilenameExt, extensions)
}
// MarkFlagCustom instructs the various shell completion implementations to
// limit completions for this flag to the specified extensions (patterns).
// MarkFlagCustom adds the BashCompCustom annotation to the named flag, if it exists.
// The bash completion script will call the bash function f for the flag.
//
// Shell Completion compatibility matrix: bash, zsh
// This will only work for bash completion.
// It is recommended to instead use c.RegisterFlagCompletionFunc(...) which allows
// to register a Go function which will work across all shells.
func MarkFlagCustom(flags *pflag.FlagSet, name string, f string) error {
return flags.SetAnnotation(name, BashCompCustom, []string{f})
}
// MarkFlagDirname instructs the various shell completion implementations to
// complete only directories with this named flag.
//
// Shell Completion compatibility matrix: zsh
// limit completions for the named flag to directory names.
func (c *Command) MarkFlagDirname(name string) error {
return MarkFlagDirname(c.Flags(), name)
}
// MarkPersistentFlagDirname instructs the various shell completion
// implementations to complete only directories with this persistent named flag.
//
// Shell Completion compatibility matrix: zsh
// implementations to limit completions for the named persistent flag to
// directory names.
func (c *Command) MarkPersistentFlagDirname(name string) error {
return MarkFlagDirname(c.PersistentFlags(), name)
}
// MarkFlagDirname instructs the various shell completion implementations to
// complete only directories with this specified flag.
//
// Shell Completion compatibility matrix: zsh
// limit completions for the named flag to directory names.
func MarkFlagDirname(flags *pflag.FlagSet, name string) error {
zshPattern := "-(/)"
return flags.SetAnnotation(name, zshCompDirname, []string{zshPattern})
return flags.SetAnnotation(name, BashCompSubdirsInDir, []string{})
}

429
shell_completions.md Normal file
View File

@ -0,0 +1,429 @@
# Generating shell completions
Cobra can generate shell completions for multiple shells.
The currently supported shells are:
- Bash
- Zsh
- Fish
- PowerShell
If you are using the generator you can create a completion command by running
```bash
cobra add completion
```
and then modifying the generated `cmd/completion.go` file to look something like this
(writing the shell script to stdout allows the most flexible use):
```go
var completionCmd = &cobra.Command{
Use: "completion [bash|zsh|fish|powershell]",
Short: "Generate completion script",
Long: `To load completions:
Bash:
$ source <(yourprogram completion bash)
# To load completions for each session, execute once:
Linux:
$ yourprogram completion bash > /etc/bash_completion.d/yourprogram
MacOS:
$ yourprogram completion bash > /usr/local/etc/bash_completion.d/yourprogram
Zsh:
$ source <(yourprogram completion zsh)
# To load completions for each session, execute once:
$ yourprogram completion zsh > "${fpath[1]}/_yourprogram"
Fish:
$ yourprogram completion fish | source
# To load completions for each session, execute once:
$ yourprogram completion fish > ~/.config/fish/completions/yourprogram.fish
`,
DisableFlagsInUseLine: true,
ValidArgs: []string{"bash", "zsh", "fish", "powershell"},
Args: cobra.ExactValidArgs(1),
Run: func(cmd *cobra.Command, args []string) {
switch args[0] {
case "bash":
cmd.Root().GenBashCompletion(os.Stdout)
case "zsh":
cmd.Root().GenZshCompletion(os.Stdout)
case "fish":
cmd.Root().GenFishCompletion(os.Stdout, true)
case "powershell":
cmd.Root().GenPowerShellCompletion(os.Stdout)
}
},
}
```
**Note:** The cobra generator may include messages printed to stdout for example if the config file is loaded, this will break the auto complete script so must be removed.
# Customizing completions
The generated completion scripts will automatically handle completing commands and flags. However, you can make your completions much more powerful by providing information to complete your program's nouns and flag values.
## Completion of nouns
### Static completion of nouns
Cobra allows you to provide a pre-defined list of completion choices for your nouns using the `ValidArgs` field.
For example, if you want `kubectl get [tab][tab]` to show a list of valid "nouns" you have to set them.
Some simplified code from `kubectl get` looks like:
```go
validArgs []string = { "pod", "node", "service", "replicationcontroller" }
cmd := &cobra.Command{
Use: "get [(-o|--output=)json|yaml|template|...] (RESOURCE [NAME] | RESOURCE/NAME ...)",
Short: "Display one or many resources",
Long: get_long,
Example: get_example,
Run: func(cmd *cobra.Command, args []string) {
err := RunGet(f, out, cmd, args)
util.CheckErr(err)
},
ValidArgs: validArgs,
}
```
Notice we put the `ValidArgs` field on the `get` sub-command. Doing so will give results like:
```bash
$ kubectl get [tab][tab]
node pod replicationcontroller service
```
#### Aliases for nouns
If your nouns have aliases, you can define them alongside `ValidArgs` using `ArgAliases`:
```go
argAliases []string = { "pods", "nodes", "services", "svc", "replicationcontrollers", "rc" }
cmd := &cobra.Command{
...
ValidArgs: validArgs,
ArgAliases: argAliases
}
```
The aliases are not shown to the user on tab completion, but they are accepted as valid nouns by
the completion algorithm if entered manually, e.g. in:
```bash
$ kubectl get rc [tab][tab]
backend frontend database
```
Note that without declaring `rc` as an alias, the completion algorithm would not know to show the list of
replication controllers following `rc`.
### Dynamic completion of nouns
In some cases it is not possible to provide a list of completions in advance. Instead, the list of completions must be determined at execution-time. In a similar fashion as for static completions, you can use the `ValidArgsFunction` field to provide a Go function that Cobra will execute when it needs the list of completion choices for the nouns of a command. Note that either `ValidArgs` or `ValidArgsFunction` can be used for a single cobra command, but not both.
Simplified code from `helm status` looks like:
```go
cmd := &cobra.Command{
Use: "status RELEASE_NAME",
Short: "Display the status of the named release",
Long: status_long,
RunE: func(cmd *cobra.Command, args []string) {
RunGet(args[0])
},
ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
if len(args) != 0 {
return nil, cobra.ShellCompDirectiveNoFileComp
}
return getReleasesFromCluster(toComplete), cobra.ShellCompDirectiveNoFileComp
},
}
```
Where `getReleasesFromCluster()` is a Go function that obtains the list of current Helm releases running on the Kubernetes cluster.
Notice we put the `ValidArgsFunction` on the `status` sub-command. Let's assume the Helm releases on the cluster are: `harbor`, `notary`, `rook` and `thanos` then this dynamic completion will give results like:
```bash
$ helm status [tab][tab]
harbor notary rook thanos
```
You may have noticed the use of `cobra.ShellCompDirective`. These directives are bit fields allowing to control some shell completion behaviors for your particular completion. You can combine them with the bit-or operator such as `cobra.ShellCompDirectiveNoSpace | cobra.ShellCompDirectiveNoFileComp`
```go
// Indicates that the shell will perform its default behavior after completions
// have been provided (this implies none of the other directives).
ShellCompDirectiveDefault
// Indicates an error occurred and completions should be ignored.
ShellCompDirectiveError
// Indicates that the shell should not add a space after the completion,
// even if there is a single completion provided.
ShellCompDirectiveNoSpace
// Indicates that the shell should not provide file completion even when
// no completion is provided.
ShellCompDirectiveNoFileComp
// Indicates that the returned completions should be used as file extension filters.
// For example, to complete only files of the form *.json or *.yaml:
// return []string{"yaml", "json"}, ShellCompDirectiveFilterFileExt
// For flags, using MarkFlagFilename() and MarkPersistentFlagFilename()
// is a shortcut to using this directive explicitly.
//
ShellCompDirectiveFilterFileExt
// Indicates that only directory names should be provided in file completion.
// For example:
// return nil, ShellCompDirectiveFilterDirs
// For flags, using MarkFlagDirname() is a shortcut to using this directive explicitly.
//
// To request directory names within another directory, the returned completions
// should specify a single directory name within which to search. For example,
// to complete directories within "themes/":
// return []string{"themes"}, ShellCompDirectiveFilterDirs
//
ShellCompDirectiveFilterDirs
```
***Note***: When using the `ValidArgsFunction`, Cobra will call your registered function after having parsed all flags and arguments provided in the command-line. You therefore don't need to do this parsing yourself. For example, when a user calls `helm status --namespace my-rook-ns [tab][tab]`, Cobra will call your registered `ValidArgsFunction` after having parsed the `--namespace` flag, as it would have done when calling the `RunE` function.
#### Debugging
Cobra achieves dynamic completion through the use of a hidden command called by the completion script. To debug your Go completion code, you can call this hidden command directly:
```bash
$ helm __complete status har<ENTER>
harbor
:4
Completion ended with directive: ShellCompDirectiveNoFileComp # This is on stderr
```
***Important:*** If the noun to complete is empty (when the user has not yet typed any letters of that noun), you must pass an empty parameter to the `__complete` command:
```bash
$ helm __complete status ""<ENTER>
harbor
notary
rook
thanos
:4
Completion ended with directive: ShellCompDirectiveNoFileComp # This is on stderr
```
Calling the `__complete` command directly allows you to run the Go debugger to troubleshoot your code. You can also add printouts to your code; Cobra provides the following functions to use for printouts in Go completion code:
```go
// Prints to the completion script debug file (if BASH_COMP_DEBUG_FILE
// is set to a file path) and optionally prints to stderr.
cobra.CompDebug(msg string, printToStdErr bool) {
cobra.CompDebugln(msg string, printToStdErr bool)
// Prints to the completion script debug file (if BASH_COMP_DEBUG_FILE
// is set to a file path) and to stderr.
cobra.CompError(msg string)
cobra.CompErrorln(msg string)
```
***Important:*** You should **not** leave traces that print directly to stdout in your completion code as they will be interpreted as completion choices by the completion script. Instead, use the cobra-provided debugging traces functions mentioned above.
## Completions for flags
### Mark flags as required
Most of the time completions will only show sub-commands. But if a flag is required to make a sub-command work, you probably want it to show up when the user types [tab][tab]. You can mark a flag as 'Required' like so:
```go
cmd.MarkFlagRequired("pod")
cmd.MarkFlagRequired("container")
```
and you'll get something like
```bash
$ kubectl exec [tab][tab]
-c --container= -p --pod=
```
### Specify dynamic flag completion
As for nouns, Cobra provides a way of defining dynamic completion of flags. To provide a Go function that Cobra will execute when it needs the list of completion choices for a flag, you must register the function using the `command.RegisterFlagCompletionFunc()` function.
```go
flagName := "output"
cmd.RegisterFlagCompletionFunc(flagName, func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
return []string{"json", "table", "yaml"}, cobra.ShellCompDirectiveDefault
})
```
Notice that calling `RegisterFlagCompletionFunc()` is done through the `command` with which the flag is associated. In our example this dynamic completion will give results like so:
```bash
$ helm status --output [tab][tab]
json table yaml
```
#### Debugging
You can also easily debug your Go completion code for flags:
```bash
$ helm __complete status --output ""
json
table
yaml
:4
Completion ended with directive: ShellCompDirectiveNoFileComp # This is on stderr
```
***Important:*** You should **not** leave traces that print to stdout in your completion code as they will be interpreted as completion choices by the completion script. Instead, use the cobra-provided debugging traces functions mentioned further above.
### Specify valid filename extensions for flags that take a filename
To limit completions of flag values to file names with certain extensions you can either use the different `MarkFlagFilename()` functions or a combination of `RegisterFlagCompletionFunc()` and `ShellCompDirectiveFilterFileExt`, like so:
```go
flagName := "output"
cmd.MarkFlagFilename(flagName, "yaml", "json")
```
or
```go
flagName := "output"
cmd.RegisterFlagCompletionFunc(flagName, func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
return []string{"yaml", "json"}, ShellCompDirectiveFilterFileExt})
```
### Limit flag completions to directory names
To limit completions of flag values to directory names you can either use the `MarkFlagDirname()` functions or a combination of `RegisterFlagCompletionFunc()` and `ShellCompDirectiveFilterDirs`, like so:
```go
flagName := "output"
cmd.MarkFlagDirname(flagName)
```
or
```go
flagName := "output"
cmd.RegisterFlagCompletionFunc(flagName, func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
return nil, cobra.ShellCompDirectiveFilterDirs
})
```
To limit completions of flag values to directory names *within another directory* you can use a combination of `RegisterFlagCompletionFunc()` and `ShellCompDirectiveFilterDirs` like so:
```go
flagName := "output"
cmd.RegisterFlagCompletionFunc(flagName, func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
return []string{"themes"}, cobra.ShellCompDirectiveFilterDirs
})
```
### Descriptions for completions
Both `zsh` and `fish` allow for descriptions to annotate completion choices. For commands and flags, Cobra will provide the descriptions automatically, based on usage information. For example, using zsh:
```
$ helm s[tab]
search -- search for a keyword in charts
show -- show information of a chart
status -- displays the status of the named release
```
while using fish:
```
$ helm s[tab]
search (search for a keyword in charts) show (show information of a chart) status (displays the status of the named release)
```
Cobra allows you to add annotations to your own completions. Simply add the annotation text after each completion, following a `\t` separator. This technique applies to completions returned by `ValidArgs`, `ValidArgsFunction` and `RegisterFlagCompletionFunc()`. For example:
```go
ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
return []string{"harbor\tAn image registry", "thanos\tLong-term metrics"}, cobra.ShellCompDirectiveNoFileComp
}}
```
or
```go
ValidArgs: []string{"bash\tCompletions for bash", "zsh\tCompletions for zsh"}
```
## Bash completions
### Dependencies
The bash completion script generated by Cobra requires the `bash_completion` package. You should update the help text of your completion command to show how to install the `bash_completion` package ([Kubectl docs](https://kubernetes.io/docs/tasks/tools/install-kubectl/#enabling-shell-autocompletion))
### Aliases
You can also configure `bash` aliases for your program and they will also support completions.
```bash
alias aliasname=origcommand
complete -o default -F __start_origcommand aliasname
# and now when you run `aliasname` completion will make
# suggestions as it did for `origcommand`.
$ aliasname <tab><tab>
completion firstcommand secondcommand
```
### Bash legacy dynamic completions
For backwards-compatibility, Cobra still supports its bash legacy dynamic completion solution.
Please refer to [Bash Completions](bash_completions.md) for details.
## Zsh completions
Cobra supports native Zsh completion generated from the root `cobra.Command`.
The generated completion script should be put somewhere in your `$fpath` and be named
`_<yourProgram>`.
Zsh supports descriptions for completions. Cobra will provide the description automatically,
based on usage information. Cobra provides a way to completely disable such descriptions by
using `GenZshCompletionNoDesc()` or `GenZshCompletionFileNoDesc()`. You can choose to make
this a configurable option to your users.
```
# With descriptions
$ helm s[tab]
search -- search for a keyword in charts
show -- show information of a chart
status -- displays the status of the named release
# Without descriptions
$ helm s[tab]
search show status
```
*Note*: Because of backwards-compatibility requirements, we were forced to have a different API to disable completion descriptions between `Zsh` and `Fish`.
### Limitations
* Custom completions implemented in Bash scripting (legacy) are not supported and will be ignored for `zsh` (including the use of the `BashCompCustom` flag annotation).
* You should instead use `ValidArgsFunction` and `RegisterFlagCompletionFunc()` which are portable to the different shells (`bash`, `zsh`, `fish`).
* The function `MarkFlagCustom()` is not supported and will be ignored for `zsh`.
* You should instead use `RegisterFlagCompletionFunc()`.
### Zsh completions standardization
Cobra 1.1 standardized its zsh completion support to align it with its other shell completions. Although the API was kept backwards-compatible, some small changes in behavior were introduced.
Please refer to [Zsh Completions](zsh_completions.md) for details.
## Fish completions
Cobra supports native Fish completions generated from the root `cobra.Command`. You can use the `command.GenFishCompletion()` or `command.GenFishCompletionFile()` functions. You must provide these functions with a parameter indicating if the completions should be annotated with a description; Cobra will provide the description automatically based on usage information. You can choose to make this option configurable by your users.
```
# With descriptions
$ helm s[tab]
search (search for a keyword in charts) show (show information of a chart) status (displays the status of the named release)
# Without descriptions
$ helm s[tab]
search show status
```
*Note*: Because of backwards-compatibility requirements, we were forced to have a different API to disable completion descriptions between `Zsh` and `Fish`.
### Limitations
* Custom completions implemented in Bash scripting (legacy) are not supported and will be ignored for `fish` (including the use of the `BashCompCustom` flag annotation).
* You should instead use `ValidArgsFunction` and `RegisterFlagCompletionFunc()` which are portable to the different shells (`bash`, `zsh`, `fish`).
* The function `MarkFlagCustom()` is not supported and will be ignored for `fish`.
* You should instead use `RegisterFlagCompletionFunc()`.
* The following flag completion annotations are not supported and will be ignored for `fish`:
* `BashCompFilenameExt` (filtering by file extension)
* `BashCompSubdirsInDir` (filtering by directory)
* The functions corresponding to the above annotations are consequently not supported and will be ignored for `fish`:
* `MarkFlagFilename()` and `MarkPersistentFlagFilename()` (filtering by file extension)
* `MarkFlagDirname()` and `MarkPersistentFlagDirname()` (filtering by directory)
* Similarly, the following completion directives are not supported and will be ignored for `fish`:
* `ShellCompDirectiveFilterFileExt` (filtering by file extension)
* `ShellCompDirectiveFilterDirs` (filtering by directory)
## PowerShell completions
Please refer to [PowerShell Completions](powershell_completions.md) for details.

523
zsh_completions.go
View File

@ -1,336 +1,235 @@
package cobra
import (
"encoding/json"
"bytes"
"fmt"
"io"
"os"
"sort"
"strings"
"text/template"
"github.com/spf13/pflag"
)
const (
zshCompArgumentAnnotation = "cobra_annotations_zsh_completion_argument_annotation"
zshCompArgumentFilenameComp = "cobra_annotations_zsh_completion_argument_file_completion"
zshCompArgumentWordComp = "cobra_annotations_zsh_completion_argument_word_completion"
zshCompDirname = "cobra_annotations_zsh_dirname"
)
var (
zshCompFuncMap = template.FuncMap{
"genZshFuncName": zshCompGenFuncName,
"extractFlags": zshCompExtractFlag,
"genFlagEntryForZshArguments": zshCompGenFlagEntryForArguments,
"extractArgsCompletions": zshCompExtractArgumentCompletionHintsForRendering,
}
zshCompletionText = `
{{/* should accept Command (that contains subcommands) as parameter */}}
{{define "argumentsC" -}}
{{ $cmdPath := genZshFuncName .}}
function {{$cmdPath}} {
local -a commands
_arguments -C \{{- range extractFlags .}}
{{genFlagEntryForZshArguments .}} \{{- end}}
"1: :->cmnds" \
"*::arg:->args"
case $state in
cmnds)
commands=({{range .Commands}}{{if not .Hidden}}
"{{.Name}}:{{.Short}}"{{end}}{{end}}
)
_describe "command" commands
;;
esac
case "$words[1]" in {{- range .Commands}}{{if not .Hidden}}
{{.Name}})
{{$cmdPath}}_{{.Name}}
;;{{end}}{{end}}
esac
}
{{range .Commands}}{{if not .Hidden}}
{{template "selectCmdTemplate" .}}
{{- end}}{{end}}
{{- end}}
{{/* should accept Command without subcommands as parameter */}}
{{define "arguments" -}}
function {{genZshFuncName .}} {
{{" _arguments"}}{{range extractFlags .}} \
{{genFlagEntryForZshArguments . -}}
{{end}}{{range extractArgsCompletions .}} \
{{.}}{{end}}
}
{{end}}
{{/* dispatcher for commands with or without subcommands */}}
{{define "selectCmdTemplate" -}}
{{if .Hidden}}{{/* ignore hidden*/}}{{else -}}
{{if .Commands}}{{template "argumentsC" .}}{{else}}{{template "arguments" .}}{{end}}
{{- end}}
{{- end}}
{{/* template entry point */}}
{{define "Main" -}}
#compdef _{{.Name}} {{.Name}}
{{template "selectCmdTemplate" .}}
{{end}}
`
)
// zshCompArgsAnnotation is used to encode/decode zsh completion for
// arguments to/from Command.Annotations.
type zshCompArgsAnnotation map[int]zshCompArgHint
type zshCompArgHint struct {
// Indicates the type of the completion to use. One of:
// zshCompArgumentFilenameComp or zshCompArgumentWordComp
Tipe string `json:"type"`
// A value for the type above (globs for file completion or words)
Options []string `json:"options"`
}
// GenZshCompletionFile generates zsh completion file.
// GenZshCompletionFile generates zsh completion file including descriptions.
func (c *Command) GenZshCompletionFile(filename string) error {
return c.genZshCompletionFile(filename, true)
}
// GenZshCompletion generates zsh completion file including descriptions
// and writes it to the passed writer.
func (c *Command) GenZshCompletion(w io.Writer) error {
return c.genZshCompletion(w, true)
}
// GenZshCompletionFileNoDesc generates zsh completion file without descriptions.
func (c *Command) GenZshCompletionFileNoDesc(filename string) error {
return c.genZshCompletionFile(filename, false)
}
// GenZshCompletionNoDesc generates zsh completion file without descriptions
// and writes it to the passed writer.
func (c *Command) GenZshCompletionNoDesc(w io.Writer) error {
return c.genZshCompletion(w, false)
}
// MarkZshCompPositionalArgumentFile only worked for zsh and its behavior was
// not consistent with Bash completion. It has therefore been disabled.
// Instead, when no other completion is specified, file completion is done by
// default for every argument. One can disable file completion on a per-argument
// basis by using ValidArgsFunction and ShellCompDirectiveNoFileComp.
// To achieve file extension filtering, one can use ValidArgsFunction and
// ShellCompDirectiveFilterFileExt.
//
// Deprecated
func (c *Command) MarkZshCompPositionalArgumentFile(argPosition int, patterns ...string) error {
return nil
}
// MarkZshCompPositionalArgumentWords only worked for zsh. It has therefore
// been disabled.
// To achieve the same behavior across all shells, one can use
// ValidArgs (for the first argument only) or ValidArgsFunction for
// any argument (can include the first one also).
//
// Deprecated
func (c *Command) MarkZshCompPositionalArgumentWords(argPosition int, words ...string) error {
return nil
}
func (c *Command) genZshCompletionFile(filename string, includeDesc bool) error {
outFile, err := os.Create(filename)
if err != nil {
return err
}
defer outFile.Close()
return c.GenZshCompletion(outFile)
return c.genZshCompletion(outFile, includeDesc)
}
// GenZshCompletion generates a zsh completion file and writes to the passed
// writer. The completion always run on the root command regardless of the
// command it was called from.
func (c *Command) GenZshCompletion(w io.Writer) error {
tmpl, err := template.New("Main").Funcs(zshCompFuncMap).Parse(zshCompletionText)
if err != nil {
return fmt.Errorf("error creating zsh completion template: %v", err)
}
return tmpl.Execute(w, c.Root())
func (c *Command) genZshCompletion(w io.Writer, includeDesc bool) error {
buf := new(bytes.Buffer)
genZshComp(buf, c.Name(), includeDesc)
_, err := buf.WriteTo(w)
return err
}
// MarkZshCompPositionalArgumentFile marks the specified argument (first
// argument is 1) as completed by file selection. patterns (e.g. "*.txt") are
// optional - if not provided the completion will search for all files.
func (c *Command) MarkZshCompPositionalArgumentFile(argPosition int, patterns ...string) error {
if argPosition < 1 {
return fmt.Errorf("Invalid argument position (%d)", argPosition)
func genZshComp(buf *bytes.Buffer, name string, includeDesc bool) {
compCmd := ShellCompRequestCmd
if !includeDesc {
compCmd = ShellCompNoDescRequestCmd
}
annotation, err := c.zshCompGetArgsAnnotations()
if err != nil {
return err
}
if c.zshcompArgsAnnotationnIsDuplicatePosition(annotation, argPosition) {
return fmt.Errorf("Duplicate annotation for positional argument at index %d", argPosition)
}
annotation[argPosition] = zshCompArgHint{
Tipe: zshCompArgumentFilenameComp,
Options: patterns,
}
return c.zshCompSetArgsAnnotations(annotation)
buf.WriteString(fmt.Sprintf(`#compdef _%[1]s %[1]s
# zsh completion for %-36[1]s -*- shell-script -*-
__%[1]s_debug()
{
local file="$BASH_COMP_DEBUG_FILE"
if [[ -n ${file} ]]; then
echo "$*" >> "${file}"
fi
}
// MarkZshCompPositionalArgumentWords marks the specified positional argument
// (first argument is 1) as completed by the provided words. At east one word
// must be provided, spaces within words will be offered completion with
// "word\ word".
func (c *Command) MarkZshCompPositionalArgumentWords(argPosition int, words ...string) error {
if argPosition < 1 {
return fmt.Errorf("Invalid argument position (%d)", argPosition)
}
if len(words) == 0 {
return fmt.Errorf("Trying to set empty word list for positional argument %d", argPosition)
}
annotation, err := c.zshCompGetArgsAnnotations()
if err != nil {
return err
}
if c.zshcompArgsAnnotationnIsDuplicatePosition(annotation, argPosition) {
return fmt.Errorf("Duplicate annotation for positional argument at index %d", argPosition)
}
annotation[argPosition] = zshCompArgHint{
Tipe: zshCompArgumentWordComp,
Options: words,
}
return c.zshCompSetArgsAnnotations(annotation)
_%[1]s()
{
local shellCompDirectiveError=%[3]d
local shellCompDirectiveNoSpace=%[4]d
local shellCompDirectiveNoFileComp=%[5]d
local shellCompDirectiveFilterFileExt=%[6]d
local shellCompDirectiveFilterDirs=%[7]d
local lastParam lastChar flagPrefix requestComp out directive compCount comp lastComp
local -a completions
__%[1]s_debug "\n========= starting completion logic =========="
__%[1]s_debug "CURRENT: ${CURRENT}, words[*]: ${words[*]}"
# The user could have moved the cursor backwards on the command-line.
# We need to trigger completion from the $CURRENT location, so we need
# to truncate the command-line ($words) up to the $CURRENT location.
# (We cannot use $CURSOR as its value does not work when a command is an alias.)
words=("${=words[1,CURRENT]}")
__%[1]s_debug "Truncated words[*]: ${words[*]},"
lastParam=${words[-1]}
lastChar=${lastParam[-1]}
__%[1]s_debug "lastParam: ${lastParam}, lastChar: ${lastChar}"
# For zsh, when completing a flag with an = (e.g., %[1]s -n=<TAB>)
# completions must be prefixed with the flag
setopt local_options BASH_REMATCH
if [[ "${lastParam}" =~ '-.*=' ]]; then
# We are dealing with a flag with an =
flagPrefix="-P ${BASH_REMATCH}"
fi
# Prepare the command to obtain completions
requestComp="${words[1]} %[2]s ${words[2,-1]}"
if [ "${lastChar}" = "" ]; then
# If the last parameter is complete (there is a space following it)
# We add an extra empty parameter so we can indicate this to the go completion code.
__%[1]s_debug "Adding extra empty parameter"
requestComp="${requestComp} \"\""
fi
__%[1]s_debug "About to call: eval ${requestComp}"
# Use eval to handle any environment variables and such
out=$(eval ${requestComp} 2>/dev/null)
__%[1]s_debug "completion output: ${out}"
# Extract the directive integer following a : from the last line
local lastLine
while IFS='\n' read -r line; do
lastLine=${line}
done < <(printf "%%s\n" "${out[@]}")
__%[1]s_debug "last line: ${lastLine}"
if [ "${lastLine[1]}" = : ]; then
directive=${lastLine[2,-1]}
# Remove the directive including the : and the newline
local suffix
(( suffix=${#lastLine}+2))
out=${out[1,-$suffix]}
else
# There is no directive specified. Leave $out as is.
__%[1]s_debug "No directive found. Setting do default"
directive=0
fi
__%[1]s_debug "directive: ${directive}"
__%[1]s_debug "completions: ${out}"
__%[1]s_debug "flagPrefix: ${flagPrefix}"
if [ $((directive & shellCompDirectiveError)) -ne 0 ]; then
__%[1]s_debug "Completion received error. Ignoring completions."
return
fi
compCount=0
while IFS='\n' read -r comp; do
if [ -n "$comp" ]; then
# If requested, completions are returned with a description.
# The description is preceded by a TAB character.
# For zsh's _describe, we need to use a : instead of a TAB.
# We first need to escape any : as part of the completion itself.
comp=${comp//:/\\:}
local tab=$(printf '\t')
comp=${comp//$tab/:}
((compCount++))
__%[1]s_debug "Adding completion: ${comp}"
completions+=${comp}
lastComp=$comp
fi
done < <(printf "%%s\n" "${out[@]}")
if [ $((directive & shellCompDirectiveFilterFileExt)) -ne 0 ]; then
# File extension filtering
local filteringCmd
filteringCmd='_files'
for filter in ${completions[@]}; do
if [ ${filter[1]} != '*' ]; then
# zsh requires a glob pattern to do file filtering
filter="\*.$filter"
fi
filteringCmd+=" -g $filter"
done
filteringCmd+=" ${flagPrefix}"
__%[1]s_debug "File filtering command: $filteringCmd"
_arguments '*:filename:'"$filteringCmd"
elif [ $((directive & shellCompDirectiveFilterDirs)) -ne 0 ]; then
# File completion for directories only
local subDir
subdir="${completions[1]}"
if [ -n "$subdir" ]; then
__%[1]s_debug "Listing directories in $subdir"
pushd "${subdir}" >/dev/null 2>&1
else
__%[1]s_debug "Listing directories in ."
fi
_arguments '*:dirname:_files -/'" ${flagPrefix}"
if [ -n "$subdir" ]; then
popd >/dev/null 2>&1
fi
elif [ $((directive & shellCompDirectiveNoSpace)) -ne 0 ] && [ ${compCount} -eq 1 ]; then
__%[1]s_debug "Activating nospace."
# We can use compadd here as there is no description when
# there is only one completion.
compadd -S '' "${lastComp}"
elif [ ${compCount} -eq 0 ]; then
if [ $((directive & shellCompDirectiveNoFileComp)) -ne 0 ]; then
__%[1]s_debug "deactivating file completion"
else
# Perform file completion
__%[1]s_debug "activating file completion"
_arguments '*:filename:_files'" ${flagPrefix}"
fi
else
_describe "completions" completions $(echo $flagPrefix)
fi
}
func zshCompExtractArgumentCompletionHintsForRendering(c *Command) ([]string, error) {
var result []string
annotation, err := c.zshCompGetArgsAnnotations()
if err != nil {
return nil, err
}
for k, v := range annotation {
s, err := zshCompRenderZshCompArgHint(k, v)
if err != nil {
return nil, err
}
result = append(result, s)
}
if len(c.ValidArgs) > 0 {
if _, positionOneExists := annotation[1]; !positionOneExists {
s, err := zshCompRenderZshCompArgHint(1, zshCompArgHint{
Tipe: zshCompArgumentWordComp,
Options: c.ValidArgs,
})
if err != nil {
return nil, err
}
result = append(result, s)
}
}
sort.Strings(result)
return result, nil
}
func zshCompRenderZshCompArgHint(i int, z zshCompArgHint) (string, error) {
switch t := z.Tipe; t {
case zshCompArgumentFilenameComp:
var globs []string
for _, g := range z.Options {
globs = append(globs, fmt.Sprintf(`-g "%s"`, g))
}
return fmt.Sprintf(`'%d: :_files %s'`, i, strings.Join(globs, " ")), nil
case zshCompArgumentWordComp:
var words []string
for _, w := range z.Options {
words = append(words, fmt.Sprintf("%q", w))
}
return fmt.Sprintf(`'%d: :(%s)'`, i, strings.Join(words, " ")), nil
default:
return "", fmt.Errorf("Invalid zsh argument completion annotation: %s", t)
}
}
func (c *Command) zshcompArgsAnnotationnIsDuplicatePosition(annotation zshCompArgsAnnotation, position int) bool {
_, dup := annotation[position]
return dup
}
func (c *Command) zshCompGetArgsAnnotations() (zshCompArgsAnnotation, error) {
annotation := make(zshCompArgsAnnotation)
annotationString, ok := c.Annotations[zshCompArgumentAnnotation]
if !ok {
return annotation, nil
}
err := json.Unmarshal([]byte(annotationString), &annotation)
if err != nil {
return annotation, fmt.Errorf("Error unmarshaling zsh argument annotation: %v", err)
}
return annotation, nil
}
func (c *Command) zshCompSetArgsAnnotations(annotation zshCompArgsAnnotation) error {
jsn, err := json.Marshal(annotation)
if err != nil {
return fmt.Errorf("Error marshaling zsh argument annotation: %v", err)
}
if c.Annotations == nil {
c.Annotations = make(map[string]string)
}
c.Annotations[zshCompArgumentAnnotation] = string(jsn)
return nil
}
func zshCompGenFuncName(c *Command) string {
if c.HasParent() {
return zshCompGenFuncName(c.Parent()) + "_" + c.Name()
}
return "_" + c.Name()
}
func zshCompExtractFlag(c *Command) []*pflag.Flag {
var flags []*pflag.Flag
c.LocalFlags().VisitAll(func(f *pflag.Flag) {
if !f.Hidden {
flags = append(flags, f)
}
})
c.InheritedFlags().VisitAll(func(f *pflag.Flag) {
if !f.Hidden {
flags = append(flags, f)
}
})
return flags
}
// zshCompGenFlagEntryForArguments returns an entry that matches _arguments
// zsh-completion parameters. It's too complicated to generate in a template.
func zshCompGenFlagEntryForArguments(f *pflag.Flag) string {
if f.Name == "" || f.Shorthand == "" {
return zshCompGenFlagEntryForSingleOptionFlag(f)
}
return zshCompGenFlagEntryForMultiOptionFlag(f)
}
func zshCompGenFlagEntryForSingleOptionFlag(f *pflag.Flag) string {
var option, multiMark, extras string
if zshCompFlagCouldBeSpecifiedMoreThenOnce(f) {
multiMark = "*"
}
option = "--" + f.Name
if option == "--" {
option = "-" + f.Shorthand
}
extras = zshCompGenFlagEntryExtras(f)
return fmt.Sprintf(`'%s%s[%s]%s'`, multiMark, option, zshCompQuoteFlagDescription(f.Usage), extras)
}
func zshCompGenFlagEntryForMultiOptionFlag(f *pflag.Flag) string {
var options, parenMultiMark, curlyMultiMark, extras string
if zshCompFlagCouldBeSpecifiedMoreThenOnce(f) {
parenMultiMark = "*"
curlyMultiMark = "\\*"
}
options = fmt.Sprintf(`'(%s-%s %s--%s)'{%s-%s,%s--%s}`,
parenMultiMark, f.Shorthand, parenMultiMark, f.Name, curlyMultiMark, f.Shorthand, curlyMultiMark, f.Name)
extras = zshCompGenFlagEntryExtras(f)
return fmt.Sprintf(`%s'[%s]%s'`, options, zshCompQuoteFlagDescription(f.Usage), extras)
}
func zshCompGenFlagEntryExtras(f *pflag.Flag) string {
if f.NoOptDefVal != "" {
return ""
}
extras := ":" // allow options for flag (even without assistance)
for key, values := range f.Annotations {
switch key {
case zshCompDirname:
extras = fmt.Sprintf(":filename:_files -g %q", values[0])
case BashCompFilenameExt:
extras = ":filename:_files"
for _, pattern := range values {
extras = extras + fmt.Sprintf(` -g "%s"`, pattern)
}
}
}
return extras
}
func zshCompFlagCouldBeSpecifiedMoreThenOnce(f *pflag.Flag) bool {
return strings.Contains(f.Value.Type(), "Slice") ||
strings.Contains(f.Value.Type(), "Array")
}
func zshCompQuoteFlagDescription(s string) string {
return strings.Replace(s, "'", `'\''`, -1)
`, name, compCmd,
ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp,
ShellCompDirectiveFilterFileExt, ShellCompDirectiveFilterDirs))
}

76
zsh_completions.md
View File

@ -1,39 +1,47 @@
## Generating Zsh Completion for your cobra.Command
## Generating Zsh Completion For Your cobra.Command
Cobra supports native Zsh completion generated from the root `cobra.Command`.
The generated completion script should be put somewhere in your `$fpath` named
`_<YOUR COMMAND>`.
Please refer to [Shell Completions](shell_completions.md) for details.
### What's Supported
## Zsh completions standardization
* Completion for all non-hidden subcommands using their `.Short` description.
* Completion for all non-hidden flags using the following rules:
* Filename completion works by marking the flag with `cmd.MarkFlagFilename...`
family of commands.
* The requirement for argument to the flag is decided by the `.NoOptDefVal`
flag value - if it's empty then completion will expect an argument.
* Flags of one of the various `*Array` and `*Slice` types supports multiple
specifications (with or without argument depending on the specific type).
* Completion of positional arguments using the following rules:
* Argument position for all options below starts at `1`. If argument position
`0` is requested it will raise an error.
* Use `command.MarkZshCompPositionalArgumentFile` to complete filenames. Glob
patterns (e.g. `"*.log"`) are optional - if not specified it will offer to
complete all file types.
* Use `command.MarkZshCompPositionalArgumentWords` to offer specific words for
completion. At least one word is required.
* It's possible to specify completion for some arguments and leave some
unspecified (e.g. offer words for second argument but nothing for first
argument). This will cause no completion for first argument but words
completion for second argument.
* If no argument completion was specified for 1st argument (but optionally was
specified for 2nd) and the command has `ValidArgs` it will be used as
completion options for 1st argument.
* Argument completions only offered for commands with no subcommands.
Cobra 1.1 standardized its zsh completion support to align it with its other shell completions. Although the API was kept backwards-compatible, some small changes in behavior were introduced.
### What's not yet Supported
### Deprecation summary
* Custom completion scripts are not supported yet (We should probably create zsh
specific one, doesn't make sense to re-use the bash one as the functions will
be different).
* Whatever other feature you're looking for and doesn't exist :)
See further below for more details on these deprecations.
* `cmd.MarkZshCompPositionalArgumentFile(pos, []string{})` is no longer needed. It is therefore **deprecated** and silently ignored.
* `cmd.MarkZshCompPositionalArgumentFile(pos, glob[])` is **deprecated** and silently ignored.
* Instead use `ValidArgsFunction` with `ShellCompDirectiveFilterFileExt`.
* `cmd.MarkZshCompPositionalArgumentWords()` is **deprecated** and silently ignored.
* Instead use `ValidArgsFunction`.
### Behavioral changes
**Noun completion**
|Old behavior|New behavior|
|---|---|
|No file completion by default (opposite of bash)|File completion by default; use `ValidArgsFunction` with `ShellCompDirectiveNoFileComp` to turn off file completion on a per-argument basis|
`cmd.MarkZshCompPositionalArgumentFile(pos, []string{})` used to turn on file completion on a per-argument position basis|File completion for all arguments by default; `cmd.MarkZshCompPositionalArgumentFile()` is **deprecated** and silently ignored|
|`cmd.MarkZshCompPositionalArgumentFile(pos, glob[])` used to turn on file completion **with glob filtering** on a per-argument position basis (zsh-specific)|`cmd.MarkZshCompPositionalArgumentFile()` is **deprecated** and silently ignored; use `ValidArgsFunction` with `ShellCompDirectiveFilterFileExt` for file **extension** filtering (not full glob filtering)|
|`cmd.MarkZshCompPositionalArgumentWords(pos, words[])` used to provide completion choices on a per-argument position basis (zsh-specific)|`cmd.MarkZshCompPositionalArgumentWords()` is **deprecated** and silently ignored; use `ValidArgsFunction` to achieve the same behavior|
**Flag-value completion**
|Old behavior|New behavior|
|---|---|
|No file completion by default (opposite of bash)|File completion by default; use `RegisterFlagCompletionFunc()` with `ShellCompDirectiveNoFileComp` to turn off file completion|
|`cmd.MarkFlagFilename(flag, []string{})` and similar used to turn on file completion|File completion by default; `cmd.MarkFlagFilename(flag, []string{})` no longer needed in this context and silently ignored|
|`cmd.MarkFlagFilename(flag, glob[])` used to turn on file completion **with glob filtering** (syntax of `[]string{"*.yaml", "*.yml"}` incompatible with bash)|Will continue to work, however, support for bash syntax is added and should be used instead so as to work for all shells (`[]string{"yaml", "yml"}`)|
|`cmd.MarkFlagDirname(flag)` only completes directories (zsh-specific)|Has been added for all shells|
|Completion of a flag name does not repeat, unless flag is of type `*Array` or `*Slice` (not supported by bash)|Retained for `zsh` and added to `fish`|
|Completion of a flag name does not provide the `=` form (unlike bash)|Retained for `zsh` and added to `fish`|
**Improvements**
* Custom completion support (`ValidArgsFunction` and `RegisterFlagCompletionFunc()`)
* File completion by default if no other completions found
* Handling of required flags
* File extension filtering no longer mutually exclusive with bash usage
* Completion of directory names *within* another directory
* Support for `=` form of flags

475
zsh_completions_test.go
View File

@ -1,475 +0,0 @@
package cobra
import (
"bytes"
"regexp"
"strings"
"testing"
)
func TestGenZshCompletion(t *testing.T) {
var debug bool
var option string
tcs := []struct {
name string
root *Command
expectedExpressions []string
invocationArgs []string
skip string
}{
{
name: "simple command",
root: func() *Command {
r := &Command{
Use: "mycommand",
Long: "My Command long description",
Run: emptyRun,
}
r.Flags().BoolVar(&debug, "debug", debug, "description")
return r
}(),
expectedExpressions: []string{
`(?s)function _mycommand {\s+_arguments \\\s+'--debug\[description\]'.*--help.*}`,
"#compdef _mycommand mycommand",
},
},
{
name: "flags with both long and short flags",
root: func() *Command {
r := &Command{
Use: "testcmd",
Long: "long description",
Run: emptyRun,
}
r.Flags().BoolVarP(&debug, "debug", "d", debug, "debug description")
return r
}(),
expectedExpressions: []string{
`'\(-d --debug\)'{-d,--debug}'\[debug description\]'`,
},
},
{
name: "command with subcommands and flags with values",
root: func() *Command {
r := &Command{
Use: "rootcmd",
Long: "Long rootcmd description",
}
d := &Command{
Use: "subcmd1",
Short: "Subcmd1 short description",
Run: emptyRun,
}
e := &Command{
Use: "subcmd2",
Long: "Subcmd2 short description",
Run: emptyRun,
}
r.PersistentFlags().BoolVar(&debug, "debug", debug, "description")
d.Flags().StringVarP(&option, "option", "o", option, "option description")
r.AddCommand(d, e)
return r
}(),
expectedExpressions: []string{
`commands=\(\n\s+"help:.*\n\s+"subcmd1:.*\n\s+"subcmd2:.*\n\s+\)`,
`_arguments \\\n.*'--debug\[description]'`,
`_arguments -C \\\n.*'--debug\[description]'`,
`function _rootcmd_subcmd1 {`,
`function _rootcmd_subcmd1 {`,
`_arguments \\\n.*'\(-o --option\)'{-o,--option}'\[option description]:' \\\n`,
},
},
{
name: "filename completion with and without globs",
root: func() *Command {
var file string
r := &Command{
Use: "mycmd",
Short: "my command short description",
Run: emptyRun,
}
r.Flags().StringVarP(&file, "config", "c", file, "config file")
r.MarkFlagFilename("config")
r.Flags().String("output", "", "output file")
r.MarkFlagFilename("output", "*.log", "*.txt")
return r
}(),
expectedExpressions: []string{
`\n +'\(-c --config\)'{-c,--config}'\[config file]:filename:_files'`,
`:_files -g "\*.log" -g "\*.txt"`,
},
},
{
name: "repeated variables both with and without value",
root: func() *Command {
r := genTestCommand("mycmd", true)
_ = r.Flags().BoolSliceP("debug", "d", []bool{}, "debug usage")
_ = r.Flags().StringArray("option", []string{}, "options")
return r
}(),
expectedExpressions: []string{
`'\*--option\[options]`,
`'\(\*-d \*--debug\)'{\\\*-d,\\\*--debug}`,
},
},
{
name: "generated flags --help and --version should be created even when not executing root cmd",
root: func() *Command {
r := &Command{
Use: "mycmd",
Short: "mycmd short description",
Version: "myversion",
}
s := genTestCommand("sub1", true)
r.AddCommand(s)
return s
}(),
expectedExpressions: []string{
"--version",
"--help",
},
invocationArgs: []string{
"sub1",
},
skip: "--version and --help are currently not generated when not running on root command",
},
{
name: "zsh generation should run on root command",
root: func() *Command {
r := genTestCommand("root", false)
s := genTestCommand("sub1", true)
r.AddCommand(s)
return s
}(),
expectedExpressions: []string{
"function _root {",
},
},
{
name: "flag description with single quote (') shouldn't break quotes in completion file",
root: func() *Command {
r := genTestCommand("root", true)
r.Flags().Bool("private", false, "Don't show public info")
return r
}(),
expectedExpressions: []string{
`--private\[Don'\\''t show public info]`,
},
},
{
name: "argument completion for file with and without patterns",
root: func() *Command {
r := genTestCommand("root", true)
r.MarkZshCompPositionalArgumentFile(1, "*.log")
r.MarkZshCompPositionalArgumentFile(2)
return r
}(),
expectedExpressions: []string{
`'1: :_files -g "\*.log"' \\\n\s+'2: :_files`,
},
},
{
name: "argument zsh completion for words",
root: func() *Command {
r := genTestCommand("root", true)
r.MarkZshCompPositionalArgumentWords(1, "word1", "word2")
return r
}(),
expectedExpressions: []string{
`'1: :\("word1" "word2"\)`,
},
},
{
name: "argument completion for words with spaces",
root: func() *Command {
r := genTestCommand("root", true)
r.MarkZshCompPositionalArgumentWords(1, "single", "multiple words")
return r
}(),
expectedExpressions: []string{
`'1: :\("single" "multiple words"\)'`,
},
},
{
name: "argument completion when command has ValidArgs and no annotation for argument completion",
root: func() *Command {
r := genTestCommand("root", true)
r.ValidArgs = []string{"word1", "word2"}
return r
}(),
expectedExpressions: []string{
`'1: :\("word1" "word2"\)'`,
},
},
{
name: "argument completion when command has ValidArgs and no annotation for argument at argPosition 1",
root: func() *Command {
r := genTestCommand("root", true)
r.ValidArgs = []string{"word1", "word2"}
r.MarkZshCompPositionalArgumentFile(2)
return r
}(),
expectedExpressions: []string{
`'1: :\("word1" "word2"\)' \\`,
},
},
{
name: "directory completion for flag",
root: func() *Command {
r := genTestCommand("root", true)
r.Flags().String("test", "", "test")
r.PersistentFlags().String("ptest", "", "ptest")
r.MarkFlagDirname("test")
r.MarkPersistentFlagDirname("ptest")
return r
}(),
expectedExpressions: []string{
`--test\[test]:filename:_files -g "-\(/\)"`,
`--ptest\[ptest]:filename:_files -g "-\(/\)"`,
},
},
}
for _, tc := range tcs {
t.Run(tc.name, func(t *testing.T) {
if tc.skip != "" {
t.Skip(tc.skip)
}
tc.root.Root().SetArgs(tc.invocationArgs)
tc.root.Execute()
buf := new(bytes.Buffer)
if err := tc.root.GenZshCompletion(buf); err != nil {
t.Error(err)
}
output := buf.Bytes()
for _, expr := range tc.expectedExpressions {
rgx, err := regexp.Compile(expr)
if err != nil {
t.Errorf("error compiling expression (%s): %v", expr, err)
}
if !rgx.Match(output) {
t.Errorf("expected completion (%s) to match '%s'", buf.String(), expr)
}
}
})
}
}
func TestGenZshCompletionHidden(t *testing.T) {
tcs := []struct {
name string
root *Command
expectedExpressions []string
}{
{
name: "hidden commands",
root: func() *Command {
r := &Command{
Use: "main",
Short: "main short description",
}
s1 := &Command{
Use: "sub1",
Hidden: true,
Run: emptyRun,
}
s2 := &Command{
Use: "sub2",
Short: "short sub2 description",
Run: emptyRun,
}
r.AddCommand(s1, s2)
return r
}(),
expectedExpressions: []string{
"sub1",
},
},
{
name: "hidden flags",
root: func() *Command {
var hidden string
r := &Command{
Use: "root",
Short: "root short description",
Run: emptyRun,
}
r.Flags().StringVarP(&hidden, "hidden", "H", hidden, "hidden usage")
if err := r.Flags().MarkHidden("hidden"); err != nil {
t.Errorf("Error setting flag hidden: %v\n", err)
}
return r
}(),
expectedExpressions: []string{
"--hidden",
},
},
}
for _, tc := range tcs {
t.Run(tc.name, func(t *testing.T) {
tc.root.Execute()
buf := new(bytes.Buffer)
if err := tc.root.GenZshCompletion(buf); err != nil {
t.Error(err)
}
output := buf.String()
for _, expr := range tc.expectedExpressions {
if strings.Contains(output, expr) {
t.Errorf("Expected completion (%s) not to contain '%s' but it does", output, expr)
}
}
})
}
}
func TestMarkZshCompPositionalArgumentFile(t *testing.T) {
t.Run("Doesn't allow overwriting existing positional argument", func(t *testing.T) {
c := &Command{}
if err := c.MarkZshCompPositionalArgumentFile(1, "*.log"); err != nil {
t.Errorf("Received error when we shouldn't have: %v\n", err)
}
if err := c.MarkZshCompPositionalArgumentFile(1); err == nil {
t.Error("Didn't receive an error when trying to overwrite argument position")
}
})
t.Run("Refuses to accept argPosition less then 1", func(t *testing.T) {
c := &Command{}
err := c.MarkZshCompPositionalArgumentFile(0, "*")
if err == nil {
t.Fatal("Error was not thrown when indicating argument position 0")
}
if !strings.Contains(err.Error(), "position") {
t.Errorf("expected error message '%s' to contain 'position'", err.Error())
}
})
}
func TestMarkZshCompPositionalArgumentWords(t *testing.T) {
t.Run("Doesn't allow overwriting existing positional argument", func(t *testing.T) {
c := &Command{}
if err := c.MarkZshCompPositionalArgumentFile(1, "*.log"); err != nil {
t.Errorf("Received error when we shouldn't have: %v\n", err)
}
if err := c.MarkZshCompPositionalArgumentWords(1, "hello"); err == nil {
t.Error("Didn't receive an error when trying to overwrite argument position")
}
})
t.Run("Doesn't allow calling without words", func(t *testing.T) {
c := &Command{}
if err := c.MarkZshCompPositionalArgumentWords(0); err == nil {
t.Error("Should not allow saving empty word list for annotation")
}
})
t.Run("Refuses to accept argPosition less then 1", func(t *testing.T) {
c := &Command{}
err := c.MarkZshCompPositionalArgumentWords(0, "word")
if err == nil {
t.Fatal("Should not allow setting argument position less then 1")
}
if !strings.Contains(err.Error(), "position") {
t.Errorf("Expected error '%s' to contain 'position' but didn't", err.Error())
}
})
}
func BenchmarkMediumSizeConstruct(b *testing.B) {
root := constructLargeCommandHierarchy()
// if err := root.GenZshCompletionFile("_mycmd"); err != nil {
// b.Error(err)
// }
for i := 0; i < b.N; i++ {
buf := new(bytes.Buffer)
err := root.GenZshCompletion(buf)
if err != nil {
b.Error(err)
}
}
}
func TestExtractFlags(t *testing.T) {
var debug, cmdc, cmdd bool
c := &Command{
Use: "cmdC",
Long: "Command C",
}
c.PersistentFlags().BoolVarP(&debug, "debug", "d", debug, "debug mode")
c.Flags().BoolVar(&cmdc, "cmd-c", cmdc, "Command C")
d := &Command{
Use: "CmdD",
Long: "Command D",
}
d.Flags().BoolVar(&cmdd, "cmd-d", cmdd, "Command D")
c.AddCommand(d)
resC := zshCompExtractFlag(c)
resD := zshCompExtractFlag(d)
if len(resC) != 2 {
t.Errorf("expected Command C to return 2 flags, got %d", len(resC))
}
if len(resD) != 2 {
t.Errorf("expected Command D to return 2 flags, got %d", len(resD))
}
}
func constructLargeCommandHierarchy() *Command {
var config, st1, st2 string
var long, debug bool
var in1, in2 int
var verbose []bool
r := genTestCommand("mycmd", false)
r.PersistentFlags().StringVarP(&config, "config", "c", config, "config usage")
if err := r.MarkPersistentFlagFilename("config", "*"); err != nil {
panic(err)
}
s1 := genTestCommand("sub1", true)
s1.Flags().BoolVar(&long, "long", long, "long description")
s1.Flags().BoolSliceVar(&verbose, "verbose", verbose, "verbose description")
s1.Flags().StringArray("option", []string{}, "various options")
s2 := genTestCommand("sub2", true)
s2.PersistentFlags().BoolVar(&debug, "debug", debug, "debug description")
s3 := genTestCommand("sub3", true)
s3.Hidden = true
s1_1 := genTestCommand("sub1sub1", true)
s1_1.Flags().StringVar(&st1, "st1", st1, "st1 description")
s1_1.Flags().StringVar(&st2, "st2", st2, "st2 description")
s1_2 := genTestCommand("sub1sub2", true)
s1_3 := genTestCommand("sub1sub3", true)
s1_3.Flags().IntVar(&in1, "int1", in1, "int1 description")
s1_3.Flags().IntVar(&in2, "int2", in2, "int2 description")
s1_3.Flags().StringArrayP("option", "O", []string{}, "more options")
s2_1 := genTestCommand("sub2sub1", true)
s2_2 := genTestCommand("sub2sub2", true)
s2_3 := genTestCommand("sub2sub3", true)
s2_4 := genTestCommand("sub2sub4", true)
s2_5 := genTestCommand("sub2sub5", true)
s1.AddCommand(s1_1, s1_2, s1_3)
s2.AddCommand(s2_1, s2_2, s2_3, s2_4, s2_5)
r.AddCommand(s1, s2, s3)
r.Execute()
return r
}
func genTestCommand(name string, withRun bool) *Command {
r := &Command{
Use: name,
Short: name + " short description",
Long: "Long description for " + name,
}
if withRun {
r.Run = emptyRun
}
return r
}