diff --git a/args.go b/args.go index 70e9b26..20a022b 100644 --- a/args.go +++ b/args.go @@ -107,3 +107,15 @@ func RangeArgs(min int, max int) PositionalArgs { return nil } } + +// MatchAll allows combining several PositionalArgs to work in concert. +func MatchAll(pargs ...PositionalArgs) PositionalArgs { + return func(cmd *Command, args []string) error { + for _, parg := range pargs { + if err := parg(cmd, args); err != nil { + return err + } + } + return nil + } +} diff --git a/args_test.go b/args_test.go index 0c25b97..ded3d0d 100644 --- a/args_test.go +++ b/args_test.go @@ -1,6 +1,7 @@ package cobra import ( + "fmt" "strings" "testing" ) @@ -243,3 +244,51 @@ func TestChildTakesArgs(t *testing.T) { t.Fatalf("Unexpected error: %v", err) } } + +func TestMatchAll(t *testing.T) { + // Somewhat contrived example check that ensures there are exactly 3 + // arguments, and each argument is exactly 2 bytes long. + pargs := MatchAll( + ExactArgs(3), + func(cmd *Command, args []string) error { + for _, arg := range args { + if len([]byte(arg)) != 2 { + return fmt.Errorf("expected to be exactly 2 bytes long") + } + } + return nil + }, + ) + + testCases := map[string]struct { + args []string + fail bool + }{ + "happy path": { + []string{"aa", "bb", "cc"}, + false, + }, + "incorrect number of args": { + []string{"aa", "bb", "cc", "dd"}, + true, + }, + "incorrect number of bytes in one arg": { + []string{"aa", "bb", "abc"}, + true, + }, + } + + rootCmd := &Command{Use: "root", Args: pargs, Run: emptyRun} + + for name, tc := range testCases { + t.Run(name, func(t *testing.T) { + _, err := executeCommand(rootCmd, tc.args...) + if err != nil && !tc.fail { + t.Errorf("unexpected: %v\n", err) + } + if err == nil && tc.fail { + t.Errorf("expected error") + } + }) + } +} diff --git a/user_guide.md b/user_guide.md index 3ab111c..e87cdf2 100644 --- a/user_guide.md +++ b/user_guide.md @@ -315,6 +315,7 @@ The following validators are built in: - `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). An example of setting the custom validator: