Options get doubled in non validating arg group when used in MixIn

[sfeigl]

When using a non-validating ArgGroup in a MixIn, the options of the ArgGroup are doubled in the "Usage" line. When placing the ArgGroup directly in the command class, the options are not doubled. When using a validating ArgGroup the options are also not doubled - as expected. As far as I tested to problem only occurs when using non-validating ArgGroups in a MixIn

I am using the ArgGroup to put a heading above a set of options that are added by a loadable plugin. The intention is to make clear which option belongs to which plugin.

Example:

plugin1:
--option
--anotherOption
plugin2:
--yetAnotherOption

The this code to reproduce the problem:

Minimal reproducing example

Actual output of picocli:

Force help
Usage: Test [--double] [--double]
Heading
--double This option is doubled

What I expect:

Force help
Usage: Test [--double]
Heading
--double This option is doubled

[remkop]

Thank you for raising this. Sounds like you have found a bug. I will look into it when I have some time.

[remkop]

This is a bug caused by a change in the implementation for equals for ArgSpec.
I have to dig a bit into the history of this change...

            protected boolean equalsImpl(ArgSpec other) {
                return this.commandSpec == other.commandSpec <--- 

Test demonstrating the issue:

import org.junit.jupiter.api.Test;
import picocli.CommandLine;

import java.util.concurrent.Callable;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class Issue2341 {
    @CommandLine.Command
    static class TestCommand implements Callable<Integer> {
//        @CommandLine.Mixin MyMixIn myMixIn;
        public Integer call() throws Exception {
            return 0;
        }
    }

    static class MyMixIn {
        @CommandLine.ArgGroup(validate = false, heading = "Heading\n")
        private OptionGroup group;
    }

    public class OptionGroup {
        @CommandLine.Option(names="--double", description = "This option is doubled")
        boolean option;
    }

    @Test
    public void testIssue2341() {
        TestCommand testCommand = new TestCommand();
        CommandLine commandLine = new CommandLine(testCommand);
        commandLine.addMixin("myMixin", new MyMixIn());
        String usageMessage = commandLine.getUsageMessage(CommandLine.Help.Ansi.OFF);

        String expected = String.format("" +
                "Usage: <main class> [--double]%n" +
                "Heading%n" +
                "      --double   This option is doubled%n");
        assertEquals(expected, usageMessage);
    }
}