Zsh shell completion is broken when short flags exist

[bartekpacia]

Hi,

This is my first issue in this repository. Thank you for creating and maintaining this great package!

Now onto the problem: I discovered a bug with shell completions. Please see video below:

bugdemo.mp4

ArgumentParser version:

1.3.1

Swift version:

$ swift --version
swift-driver version: 1.90.11.1 Apple Swift version 5.10 (swiftlang-5.10.0.13 clang-1500.3.9.4)
Target: arm64-apple-macosx14.0

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

Use Zsh with shell completion enabled.

Then create a simple Swift command line app that uses swift-argument-parser.

├── Package.resolved
├── Package.swift
├── Sources
│   ├── Example.swift
│   └── Root.swift

Package.swift

// swift-tools-version: 5.9

import PackageDescription

let package = Package(
    name: "SAPbug",
    dependencies: [
      .package(url: "https://github.com/apple/swift-argument-parser", from: "1.0.0"),
    ],
    targets: [
        .executableTarget(
            name: "SAPbug",
            dependencies: [
                .product(name: "ArgumentParser", package: "swift-argument-parser"),
            ],
            path: "Sources"),
    ]
)

Sources/Root.swift

import ArgumentParser

@main
struct Root: ParsableCommand {
  static var configuration = CommandConfiguration(
    commandName: "SAPbug",
    version: "1.0.0",
    subcommands: [Example.self]
  )

  @Option(help: ArgumentHelp("Some caches option"))
  var entries: String = "caches"

  mutating func run() throws {
    print("Root run")
  }
}

Sources/Example.swift

import ArgumentParser

struct Example: ParsableCommand {
  static var configuration = CommandConfiguration(
    abstract: "Some example command to demo bug.",
    helpNames: [.long, .customShort("h")]
  )

  @Option(
    help: ArgumentHelp(
      "Entries to remove: \"caches\" targets OCI and IPSW caches and \"vms\" targets local VMs."
    )
  )
  var entries: String = "caches"

  @Option(
    help: ArgumentHelp(
      "Remove entries that were last accessed more than n days ago",
      valueName: "n"
    )
  )
  var olderThan: UInt?

  @Option(help: .hidden)
  var cacheBudget: UInt?

  @Option(
    help: ArgumentHelp(
      "Remove the least recently used entries that do not fit the specified space size budget n, expressed in gigabytes",
      valueName: "n"
    )
  )
  var spaceBudget: UInt?

  @Flag()
  var gc: Bool = false

  mutating func run() throws {
    print("Example run")
  }
}

Then build the executable:

swift build

Then source shell completions into FPATH. In my case I do:

./.build/debug/SAPbug --generate-completion-script zsh > /opt/homebrew/share/zsh/site-functions/_SAPbug && exec zsh

Then run ./.build/debug/SAPbug and try triggering various shell completions
(see video).

Expected behavior

$ ./.build/debug/SAPbug example [tab]
--entries       -- Entries to remove: "caches" targets OCI and IPSW caches and "vms" targets local VMs.
--help          -- Show help information.
--older-than    -- Remove entries that were last accessed more than n days ago
--space-budget  -- Remove the least recently used entries that do not fit the specified space size budget n, expressed
--version       -- Show the version.
--gc

Short options should not be suggested, or alternatively, they should not break
in such a bad way.

Actual behavior

Completions are broken.

Command invocation

$ ./.build/debug/SAPbug example [tab]
--entries
--help
--older-than
--space-budget
--version

-h



-- Entries to remove: "caches" targets OCI and IPSW caches and "vms" targets local VMs.
-- Show help information.
-- Remove entries that were last accessed more than n days ago
-- Remove the least recently used entries that do not fit the specified space size budget n, express
-- Show the version.
--entries
--help
--older-than
--space-budget
--version

-h



-- Entries to remove: "caches" targets OCI and IPSW caches and "vms" targets local VMs.
-- Show help information.
-- Remove entries that were last accessed more than n days ago
-- Remove the least recently used entries that do not fit the specified space size budget n, express
-- Show the version.
--gc