Dashes in command names break completion scripts

[natecook1000]

Dashes aren't valid variable identifier characters for Zsh (and maybe Bash just Zsh). When building a completion script for a command that includes one or more dashes in the command name, the completion script prints errors instead of providing completions.

ArgumentParser version: main branch
Swift version: Apple Swift version 5.3.2 (swiftlang-1200.0.45 clang-1200.0.32.28)

Checklist

• If possible, I've reproduced the issue using the main branch of this package
• I've searched for existing GitHub issues

Steps to Reproduce

Create a CLI tool with a dash in the command name, then generate and install a Zsh completion script for the command.

Command:

struct ExampleCommand: ParsableCommand {
  @Option var name: String
  @Flag var verbose = false
}

Script:

#compdef example-command
local context state state_descr line
_example-command_commandname=$words[1]
typeset -A opt_args

_example-command() {
    integer ret=1
    local -a args
    args+=(
        '--name:name:'
        '--verbose'
        '(-h --help)'{-h,--help}'[Print help information.]'
    )
    _arguments -w -s -S $args[@] && ret=0

    return ret
}


_custom_completion() {
    local completions=("${(@f)$($*)}")
    _describe '' completions
}

_example-command

Expected behavior

Typing example-command and then TAB should offer completions.

Actual behavior

The shell prints _example-command:3: command not found: _example-command_commandname=example-command.

[dhruvshah8]

Is this a problem with the ZshCompletionsGenerator or Parsing itself? I am having trouble finding exactly where the problem arises from, would appreciate any help. Thanks.

[natecook1000]

It's in the completions generator — specifically line 3 called out above, which creates a variable called _example-command_commandname. I think just changing any dashes in that variable name to underscores would do the trick.