Deprecate ExactValidArgs() and test combinations of args validators (#1643)

* deprecate ExactValidArgs in favour of MatchAll(OnlyValidArgs, ...)
* test combinations of args validators
* adjust docs
This commit is contained in:
Unai Martinez-Corral
2022-09-10 15:33:34 +02:00
committed by GitHub
parent 2e8ba6f308
commit 70e53f62be
3 changed files with 272 additions and 54 deletions

View File

@ -302,15 +302,15 @@ rootCmd.MarkPersistentFlagRequired("region")
### Flag Groups
If you have different flags that must be provided together (e.g. if they provide the `--username` flag they MUST provide the `--password` flag as well) then
If you have different flags that must be provided together (e.g. if they provide the `--username` flag they MUST provide the `--password` flag as well) then
Cobra can enforce that requirement:
```go
rootCmd.Flags().StringVarP(&u, "username", "u", "", "Username (required if password is set)")
rootCmd.Flags().StringVarP(&pw, "password", "p", "", "Password (required if username is set)")
rootCmd.MarkFlagsRequiredTogether("username", "password")
```
```
You can also prevent different flags from being provided together if they represent mutually
You can also prevent different flags from being provided together if they represent mutually
exclusive options such as specifying an output format as either `--json` or `--yaml` but never both:
```go
rootCmd.Flags().BoolVar(&u, "json", false, "Output in JSON")
@ -327,29 +327,47 @@ In both of these cases:
## Positional and Custom Arguments
Validation of positional arguments can be specified using the `Args` field of `Command`.
If `Args` is undefined or `nil`, it defaults to `ArbitraryArgs`.
The following validators are built in:
- `NoArgs` - the command will report an error if there are any positional args.
- `ArbitraryArgs` - the command will accept any args.
- `OnlyValidArgs` - the command will report an error if there are any positional args that are not in the `ValidArgs` field of `Command`.
- `MinimumNArgs(int)` - the command will report an error if there are not at least N positional args.
- `MaximumNArgs(int)` - the command will report an error if there are more than N positional args.
- `ExactArgs(int)` - the command will report an error if there are not exactly N positional args.
- `ExactValidArgs(int)` - the command will report an error if there are not exactly N positional args OR if there are any positional args that are not in the `ValidArgs` field of `Command`
- `RangeArgs(min, max)` - the command will report an error if the number of args is not between the minimum and maximum number of expected args.
- `MatchAll(pargs ...PositionalArgs)` - enables combining existing checks with arbitrary other checks (e.g. you want to check the ExactArgs length along with other qualities).
- Number of arguments:
- `NoArgs` - report an error if there are any positional args.
- `ArbitraryArgs` - accept any number of args.
- `MinimumNArgs(int)` - report an error if less than N positional args are provided.
- `MaximumNArgs(int)` - report an error if more than N positional args are provided.
- `ExactArgs(int)` - report an error if there are not exactly N positional args.
- `RangeArgs(min, max)` - report an error if the number of args is not between `min` and `max`.
- Content of the arguments:
- `OnlyValidArgs` - report an error if there are any positional args not specified in the `ValidArgs` field of `Command`, which can optionally be set to a list of valid values for positional args.
An example of setting the custom validator:
If `Args` is undefined or `nil`, it defaults to `ArbitraryArgs`.
Moreover, `MatchAll(pargs ...PositionalArgs)` enables combining existing checks with arbitrary other checks.
For instance, if you want to report an error if there are not exactly N positional args OR if there are any positional
args that are not in the `ValidArgs` field of `Command`, you can call `MatchAll` on `ExactArgs` and `OnlyValidArgs`, as
shown below:
```go
var cmd = &cobra.Command{
Short: "hello",
Args: MatchAll(ExactArgs(2), OnlyValidArgs),
Run: func(cmd *cobra.Command, args []string) {
fmt.Println("Hello, World!")
},
}
```
It is possible to set any custom validator that satisfies `func(cmd *cobra.Command, args []string) error`.
For example:
```go
var cmd = &cobra.Command{
Short: "hello",
Args: func(cmd *cobra.Command, args []string) error {
if len(args) < 1 {
return errors.New("requires a color argument")
// Optionally run one of the validators provided by cobra
if err := cobra.MinimumNArgs(1)(cmd, args); err != nil {
return err
}
// Run the custom validation logic
if myapp.IsValidColor(args[0]) {
return nil
}