Complete subcommands when TraverseChildren is true in bash completion

The current bash completion logic does not complete
subcommands when a local flag is set. There is also a bug
where subcommands are sometimes still getting completed. see: spf13#1172

If TraverseChildren is true we should allow subcommands
to be completed even if a local flag is set.

Closes spf13#1172

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

bash_completions.go

@@ -495,12 +495,14 @@ func writeFlag(buf *bytes.Buffer, flag *pflag.Flag, cmd *Command) {
 
 func writeLocalNonPersistentFlag(buf *bytes.Buffer, flag *pflag.Flag) {
 	name := flag.Name
-	format := "    local_nonpersistent_flags+=(\"--%s"
+	format := "    local_nonpersistent_flags+=(\"--%[1]s\")\n"
 	if len(flag.NoOptDefVal) == 0 {
-		format += "="
+		format += "    local_nonpersistent_flags+=(\"--%[1]s=\")\n"
 	}
-	format += "\")\n"
 	buf.WriteString(fmt.Sprintf(format, name))
+	if len(flag.Shorthand) > 0 {
+		buf.WriteString(fmt.Sprintf("    local_nonpersistent_flags+=(\"-%s\")\n", flag.Shorthand))
+	}
 }
 
 // Setup annotations for go completions for registered flags
@@ -535,7 +537,9 @@ func writeFlags(buf *bytes.Buffer, cmd *Command) {
 		if len(flag.Shorthand) > 0 {
 			writeShortFlag(buf, flag, cmd)
 		}
-		if localNonPersistentFlags.Lookup(flag.Name) != nil {
+		// localNonPersistentFlags are used to stop the completion of subcommands when one is set
+		// if TraverseChildren is true we should allow to complete subcommands
+		if localNonPersistentFlags.Lookup(flag.Name) != nil && !cmd.Root().TraverseChildren {
 			writeLocalNonPersistentFlag(buf, flag)
 		}
 	})

bash_completions_test.go

@@ -193,6 +193,13 @@ func TestBashCompletions(t *testing.T) {
 	checkOmit(t, output, `two_word_flags+=("--two-w-default")`)
 	checkOmit(t, output, `two_word_flags+=("-T")`)
 
+	// check local nonpersistent flag
+	check(t, output, `local_nonpersistent_flags+=("--two")`)
+	check(t, output, `local_nonpersistent_flags+=("--two=")`)
+	check(t, output, `local_nonpersistent_flags+=("-t")`)
+	check(t, output, `local_nonpersistent_flags+=("--two-w-default")`)
+	check(t, output, `local_nonpersistent_flags+=("-T")`)
+
 	checkOmit(t, output, deprecatedCmd.Name())
 
 	// If available, run shellcheck against the script.
@@ -235,3 +242,21 @@ func TestBashCompletionDeprecatedFlag(t *testing.T) {
 		t.Errorf("expected completion to not include %q flag: Got %v", flagName, output)
 	}
 }
+
+func TestBashCompletionTraverseChildren(t *testing.T) {
+	c := &Command{Use: "c", Run: emptyRun, TraverseChildren: true}
+
+	c.Flags().StringP("string-flag", "s", "", "string flag")
+	c.Flags().BoolP("bool-flag", "b", false, "bool flag")
+
+	buf := new(bytes.Buffer)
+	c.GenBashCompletion(buf)
+	output := buf.String()
+
+	// check that local nonpersistent flag are not set since we have TraverseChildren set to true
+	checkOmit(t, output, `local_nonpersistent_flags+=("--string-flag")`)
+	checkOmit(t, output, `local_nonpersistent_flags+=("--string-flag=")`)
+	checkOmit(t, output, `local_nonpersistent_flags+=("-s")`)
+	checkOmit(t, output, `local_nonpersistent_flags+=("--bool-flag")`)
+	checkOmit(t, output, `local_nonpersistent_flags+=("-b")`)
+}