feat(command): adding args to use line

Signed-off-by: danmx <daniel.iziourov@elastic.co>

command.go

@@ -242,6 +242,10 @@ type Command struct {
 	// line of a command when printing help or generating docs
 	DisableFlagsInUseLine bool
 
+	// DisableArgsInUseLine will disable the addition of [args] to the usage
+	// line of a command when printing help or generating docs
+	DisableArgsInUseLine bool
+
 	// DisableSuggestions disables the suggestions based on Levenshtein distance
 	// that go along with 'unknown command' messages.
 	DisableSuggestions bool
@@ -1415,12 +1419,12 @@ func (c *Command) UseLine() string {
 	} else {
 		useline = c.Use
 	}
-	if c.DisableFlagsInUseLine {
+	if c.HasAvailableFlags() && !strings.Contains(useline, "[flags]") && !c.DisableFlagsInUseLine {
-		return useline
-	}
-	if c.HasAvailableFlags() && !strings.Contains(useline, "[flags]") {
 		useline += " [flags]"
 	}
+	if c.HasAvailableArgs() && !strings.Contains(useline, "[args]") && !c.DisableArgsInUseLine {
+		useline += " [args]"
+	}
 	return useline
 }
 
@@ -1764,6 +1768,11 @@ func (c *Command) HasAvailableInheritedFlags() bool {
 	return c.InheritedFlags().HasAvailableFlags()
 }
 
+// HasAvailableArgs checks if the command has non-nil Args.
+func (c *Command) HasAvailableArgs() bool {
+	return c.Args != nil
+}
+
 // Flag climbs up the command tree looking for matching flag.
 func (c *Command) Flag(name string) (flag *flag.Flag) {
 	flag = c.Flags().Lookup(name)

command_test.go

@@ -2768,3 +2768,103 @@ func TestUnknownFlagShouldReturnSameErrorRegardlessOfArgPosition(t *testing.T) {
 		})
 	}
 }
+
+func TestUseLine(t *testing.T) {
+	var testFlagSet pflag.FlagSet
+	testFlagSet.AddFlag(&pflag.Flag{
+		Name: "flag_0",
+	})
+	testArgs := func(cmd *Command, args []string) error { return nil }
+	testCases := []struct {
+		Cmd     *Command
+		UseLine string
+	}{
+		{
+			&Command{
+				DisableFlagsInUseLine: true,
+				DisableArgsInUseLine:  true,
+				parent: &Command{
+					Use: "parent_use_0",
+				},
+				flags: &testFlagSet,
+				Args:  testArgs,
+				Use:   "use_0",
+			},
+			"parent_use_0 use_0",
+		},
+		{
+			&Command{
+				DisableFlagsInUseLine: false,
+				DisableArgsInUseLine:  false,
+				parent: &Command{
+					Use: "parent_use_1",
+				},
+				Use: "use_1",
+			},
+			"parent_use_1 use_1",
+		},
+		{
+			&Command{
+				DisableFlagsInUseLine: false,
+				DisableArgsInUseLine:  false,
+				Use:                   "use_2",
+			},
+			"use_2",
+		},
+		{
+			&Command{
+				DisableFlagsInUseLine: false,
+				DisableArgsInUseLine:  true,
+				parent: &Command{
+					Use: "parent_use_3",
+				},
+				flags: &testFlagSet,
+				Args:  testArgs,
+				Use:   "use_3",
+			},
+			"parent_use_3 use_3 [flags]",
+		},
+		{
+			&Command{
+				DisableFlagsInUseLine: false,
+				DisableArgsInUseLine:  false,
+				flags:                 &testFlagSet,
+				Args:                  testArgs,
+				Use:                   "use_4",
+			},
+			"use_4 [flags] [args]",
+		},
+		{
+			&Command{
+				DisableFlagsInUseLine: false,
+				DisableArgsInUseLine:  false,
+				Args:                  testArgs,
+				Use:                   "use_5",
+			},
+			"use_5 [args]",
+		},
+		{
+			&Command{
+				DisableFlagsInUseLine: false,
+				DisableArgsInUseLine:  false,
+				flags:                 &testFlagSet,
+				Use:                   "[flags] use_6",
+			},
+			"[flags] use_6",
+		},
+		{
+			&Command{
+				DisableFlagsInUseLine: false,
+				DisableArgsInUseLine:  false,
+				Args:                  testArgs,
+				Use:                   "[args] use_7",
+			},
+			"[args] use_7",
+		},
+	}
+	for i, tc := range testCases {
+		if tc.Cmd.UseLine() != tc.UseLine {
+			t.Errorf("test case no. %d mismatch.\nResult: %s\nExpect: %s", i, tc.Cmd.UseLine(), tc.UseLine)
+		}
+	}
+}