Merge pull request #2152 from Ali-Doustkani/fix_usageerrfunc_with_mutuallyexclusiveflags

Author: dearchap

command_run.go

@@ -223,7 +223,11 @@ func (cmd *Command) run(ctx context.Context, osArgs []string) (_ context.Context
 
 	for _, grp := range cmd.MutuallyExclusiveFlags {
 		if err := grp.check(cmd); err != nil {
-			_ = ShowSubcommandHelp(cmd)
+			if cmd.OnUsageError != nil {
+				err = cmd.OnUsageError(ctx, cmd, err, cmd.parent != nil)
+			} else {
+				_ = ShowSubcommandHelp(cmd)
+			}
 			return ctx, err
 		}
 	}

command_test.go

@@ -5168,6 +5168,62 @@ func TestJSONExportCommand(t *testing.T) {
 	assert.JSONEq(t, expected, string(out))
 }
 
+func TestCommand_ExclusiveFlags(t *testing.T) {
+	cmd := &Command{
+		Name: "bar",
+		MutuallyExclusiveFlags: []MutuallyExclusiveFlags{
+			{
+				Flags: [][]Flag{
+					{
+						&StringFlag{
+							Name: "foo1",
+						},
+					},
+					{
+						&StringFlag{
+							Name: "foo2",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	err := cmd.Run(buildTestContext(t), []string{"bar", "--foo1", "var1", "--foo2", "var2"})
+
+	require.Equal(t, "option foo1 cannot be set along with option foo2", err.Error())
+}
+
+func TestCommand_ExclusiveFlagsWithOnUsageError(t *testing.T) {
+	expectedErr := errors.New("my custom error")
+	cmd := &Command{
+		Name: "bar",
+		MutuallyExclusiveFlags: []MutuallyExclusiveFlags{
+			{
+				Flags: [][]Flag{
+					{
+						&StringFlag{
+							Name: "foo1",
+						},
+					},
+					{
+						&StringFlag{
+							Name: "foo2",
+						},
+					},
+				},
+			},
+		},
+		OnUsageError: func(_ context.Context, _ *Command, _ error, _ bool) error {
+			return expectedErr
+		},
+	}
+
+	actualErr := cmd.Run(buildTestContext(t), []string{"bar", "--foo1", "v1", "--foo2", "v2"})
+
+	require.ErrorIs(t, actualErr, expectedErr)
+}
+
 func TestCommand_ExclusiveFlagsWithAfter(t *testing.T) {
 	var called bool
 	cmd := &Command{