Added flags groups which are mutually exclusive but required

Fixed method naming

flag_groups.go

@@ -24,6 +24,7 @@ import (
 const (
 	requiredAsGroup           = "cobra_annotation_required_if_others_set"
 	mutuallyExclusive         = "cobra_annotation_mutually_exclusive"
+	mutuallyExclusiveRequired = "cobra_annotation_mutually_exclusive_required"
 )
 
 // MarkFlagsRequiredTogether marks the given flags with annotations so that Cobra errors
@@ -42,6 +43,22 @@ func (c *Command) MarkFlagsRequiredTogether(flagNames ...string) {
 	}
 }
 
+// MarkFlagsMutuallyExclusive marks the given flags with annotations so that Cobra errors
+// if the command is invoked with more than one flag from the given set of flags.
+func (c *Command) MarkFlagsMutuallyExclusiveRequired(flagNames ...string) {
+	c.mergePersistentFlags()
+	for _, v := range flagNames {
+		f := c.Flags().Lookup(v)
+		if f == nil {
+			panic(fmt.Sprintf("Failed to find flag %q and mark it as being in a mutually exclusive required flag group", v))
+		}
+		// Each time this is called is a single new entry; this allows it to be a member of multiple groups if needed.
+		if err := c.Flags().SetAnnotation(v, mutuallyExclusiveRequired, append(f.Annotations[mutuallyExclusiveRequired], strings.Join(flagNames, " "))); err != nil {
+			panic(err)
+		}
+	}
+}
+
 // MarkFlagsMutuallyExclusive marks the given flags with annotations so that Cobra errors
 // if the command is invoked with more than one flag from the given set of flags.
 func (c *Command) MarkFlagsMutuallyExclusive(flagNames ...string) {
@@ -71,9 +88,11 @@ func (c *Command) validateFlagGroups() error {
 	// then a map of each flag name and whether it is set or not.
 	groupStatus := map[string]map[string]bool{}
 	mutuallyExclusiveGroupStatus := map[string]map[string]bool{}
+	mutuallyExclusiveRequiredGroupStatus := map[string]map[string]bool{}
 	flags.VisitAll(func(pflag *flag.Flag) {
 		processFlagForGroupAnnotation(flags, pflag, requiredAsGroup, groupStatus)
 		processFlagForGroupAnnotation(flags, pflag, mutuallyExclusive, mutuallyExclusiveGroupStatus)
+		processFlagForGroupAnnotation(flags, pflag, mutuallyExclusiveRequired, mutuallyExclusiveRequiredGroupStatus)
 	})
 
 	if err := validateRequiredFlagGroups(groupStatus); err != nil {
@@ -82,6 +101,9 @@ func (c *Command) validateFlagGroups() error {
 	if err := validateExclusiveFlagGroups(mutuallyExclusiveGroupStatus); err != nil {
 		return err
 	}
+	if err := validateExclusiveRequiredFlagGroups(mutuallyExclusiveRequiredGroupStatus); err != nil {
+		return err
+	}
 	return nil
 }
 
@@ -162,6 +184,27 @@ func validateExclusiveFlagGroups(data map[string]map[string]bool) error {
 	return nil
 }
 
+func validateExclusiveRequiredFlagGroups(data map[string]map[string]bool) error {
+	keys := sortedKeys(data)
+	for _, flagList := range keys {
+		flagnameAndStatus := data[flagList]
+		var set []string
+		for flagname, isSet := range flagnameAndStatus {
+			if isSet {
+				set = append(set, flagname)
+			}
+		}
+		if len(set) == 1 {
+			continue
+		}
+
+		// Sort values, so they can be tested/scripted against consistently.
+		sort.Strings(set)
+		return fmt.Errorf("only one flag in the group [%v] can be set; %v were all set", flagList, set)
+	}
+	return nil
+}
+
 func sortedKeys(m map[string]map[string]bool) []string {
 	keys := make([]string, len(m))
 	i := 0
@@ -185,9 +228,11 @@ func (c *Command) enforceFlagGroupsForCompletion() {
 	flags := c.Flags()
 	groupStatus := map[string]map[string]bool{}
 	mutuallyExclusiveGroupStatus := map[string]map[string]bool{}
+	mutuallyExclusiveRequiredGroupStatus := map[string]map[string]bool{}
 	c.Flags().VisitAll(func(pflag *flag.Flag) {
 		processFlagForGroupAnnotation(flags, pflag, requiredAsGroup, groupStatus)
 		processFlagForGroupAnnotation(flags, pflag, mutuallyExclusive, mutuallyExclusiveGroupStatus)
+		processFlagForGroupAnnotation(flags, pflag, mutuallyExclusiveRequired, mutuallyExclusiveRequiredGroupStatus)
 	})
 
 	// If a flag that is part of a group is present, we make all the other flags