`clap_generate::generate()` panics on subcommands

[cpick]

Make sure you completed the following tasks

• Searched the discussions
• Searched the closes issues

Code

$ cargo new generate-panic
$ cd generate-panic
$ cat <<EOF >>Cargo.toml
clap = "3.0.0-beta.1"
clap_generate = "3.0.0-beta.1"
EOF

use clap::{Clap, FromArgMatches, IntoApp};
use clap_generate::{generate, generators::Bash};

#[derive(Clap)]
enum Command {
    Generate,
}

#[derive(Clap)]
struct Arguments {
    #[clap(subcommand)]
    command: Command,
}

fn main() {
    let mut app = Arguments::into_app();
    let Arguments { command: _c, } = Arguments::from_arg_matches(&app.get_matches_mut());

    for sc in app.get_subcommands() {
        println!(
            "name: '{}' bin_name: {:?}",
            sc.get_name(),
            sc.get_bin_name()
        );
    }

    let bin_name = app.get_bin_name().unwrap().to_owned();
    generate::<Bash, _>(&mut app, bin_name, &mut std::io::stdout());
}

Steps to reproduce the issue

1. Run cargo run generate
2. The following panic is produced:

Finished dev [unoptimized + debuginfo] target(s) in 0.02s
 Running `target/debug/generate-panic generate`

name: 'generate' bin_name: Some("generate-panic generate")
name: 'help' bin_name: None
thread 'main' panicked at 'called Option::unwrap() on a None value', /Users/cpick/.cargo/registry/src/github.com-1ecc6299db9ec823/clap_generate-3.0.0-beta.1/src/generators/mod.rs:105:31
note: run with RUST_BACKTRACE=1 environment variable to display a backtrace

Version

• Rust: rustc 1.44.1 (c7087fe00 2020-06-17)
• Clap: 3.0.0-beta.1 for clap and clap_generate, I have also reproduced with the current master (d8fccdb)

Actual Behavior Summary

Attempting to generate bash completions by running the code above as described in the "steps to reproduce" section causes a panic when trying to call sc.get_bin_name().unwrap() on any subcommand other than the one that was run (in the case of the example, the auto-generated help command).

The code above prints all the subcommands bin names and helps is None.

Expected Behavior Summary

I expected bash completions to be generated.

Additional context

None that I can think of.

Debug output

Compile clap with debug feature:

[dependencies]
clap = { version = "*", features = ["debug"] }

The output may be very long, so feel free to link to a gist or attach a text file

Debug Output

[Running 'cargo run generate']

Compiling clap_derive v3.0.0-beta.1

Compiling clap v3.0.0-beta.1

Compiling clap_generate v3.0.0-beta.1

Compiling generate-panic v0.1.0 (/Users/cpick/src/generate-panic)

Finished dev [unoptimized + debuginfo] target(s) in 9.86s

Running target/debug/generate-panic generate

[            clap::build::app] 	App::_do_parse

[            clap::build::app] 	App::_build

[            clap::build::app] 	App::_derive_display_order:generate-panic

[            clap::build::app] 	App::_derive_display_order:generate

[            clap::build::app] 	App::_create_help_and_version

[            clap::build::app] 	App::_create_help_and_version: Building --help

[            clap::build::app] 	App::_create_help_and_version: Building --version

[            clap::build::app] 	App::_create_help_and_version: Building help

[            clap::build::app] 	App::_debug_asserts

[            clap::build::arg] 	Arg::_debug_asserts:help

[            clap::build::arg] 	Arg::_debug_asserts:version

[         clap::parse::parser] 	Parser::get_matches_with

[         clap::parse::parser] 	Parser::_build

[         clap::parse::parser] 	Parser::_verify_positionals

[         clap::parse::parser] 	Parser::get_matches_with: Begin parsing '"generate"' ([103, 101, 110, 101, 114, 97, 116, 101])

[         clap::parse::parser] 	Parser::is_new_arg: "generate":NotFound

[         clap::parse::parser] 	Parser::is_new_arg: arg_allows_tac=false

[         clap::parse::parser] 	Parser::is_new_arg: probably value

[         clap::parse::parser] 	Parser::is_new_arg: starts_new_arg=false

[         clap::parse::parser] 	Parser::possible_subcommand: arg="generate"

[         clap::parse::parser] 	Parser::get_matches_with: possible_sc=true, sc=Some("generate")

[         clap::parse::parser] 	Parser::parse_subcommand

[         clap::output::usage] 	Usage::get_required_usage_from: incls=[], matcher=false, incl_last=true

[         clap::output::usage] 	Usage::get_required_usage_from: ret_val=[]

[            clap::build::app] 	App::_propagate:generate-panic

[            clap::build::app] 	App::_build

[            clap::build::app] 	App::_derive_display_order:generate

[            clap::build::app] 	App::_create_help_and_version

[            clap::build::app] 	App::_create_help_and_version: Building --help

[            clap::build::app] 	App::_create_help_and_version: Building --version

[            clap::build::app] 	App::_debug_asserts

[            clap::build::arg] 	Arg::_debug_asserts:help

[            clap::build::arg] 	Arg::_debug_asserts:version

[         clap::parse::parser] 	Parser::parse_subcommand: About to parse sc=generate

[         clap::parse::parser] 	Parser::get_matches_with

[         clap::parse::parser] 	Parser::_build

[         clap::parse::parser] 	Parser::_verify_positionals

[         clap::parse::parser] 	Parser::remove_overrides

[      clap::parse::validator] 	Validator::validate

[         clap::parse::parser] 	Parser::add_defaults

[      clap::parse::validator] 	Validator::validate_conflicts

[      clap::parse::validator] 	Validator::validate_exclusive

[      clap::parse::validator] 	Validator::gather_conflicts

[      clap::parse::validator] 	Validator::validate_required: required=ChildGraph([])

[      clap::parse::validator] 	Validator::gather_requirements

[      clap::parse::validator] 	Validator::validate_required_unless

[      clap::parse::validator] 	Validator::validate_matched_args

[         clap::parse::parser] 	Parser::remove_overrides

[      clap::parse::validator] 	Validator::validate

[         clap::parse::parser] 	Parser::add_defaults

[      clap::parse::validator] 	Validator::validate_conflicts

[      clap::parse::validator] 	Validator::validate_exclusive

[      clap::parse::validator] 	Validator::gather_conflicts

[      clap::parse::validator] 	Validator::validate_required: required=ChildGraph([])

[      clap::parse::validator] 	Validator::gather_requirements

[      clap::parse::validator] 	Validator::validate_required_unless

[      clap::parse::validator] 	Validator::validate_matched_args

[    clap::parse::arg_matcher] 	ArgMatcher::get_global_values: global_arg_vec=[]

name: 'generate' bin_name: Some("generate-panic generate")

name: 'help' bin_name: None

[clap_generate::generators::shells::bash] 	all_options_for_path: path=generate-panic

[   clap_generate::generators] 	subcommands: name=generate-panic

[   clap_generate::generators] 	subcommands: Has subcommands...true

[   clap_generate::generators] 	subcommands:iter: name=generate, bin_name=generate-panic generate

thread 'main' panicked at 'called Option::unwrap() on a None value', /Users/cpick/.cargo/registry/src/github.com-1ecc6299db9ec823/clap_generate-3.0.0-beta.1/src/generators/mod.rs:105:31

note: run with RUST_BACKTRACE=1 environment variable to display a backtrace

[Finished running. Exit status: 101]

[newAM]

Can this issue have the C: generator label added to it?

[gbrlsnchs]

I'm facing this issue even without any custom subcommands.

[pksunkara]

@logansquirel This one.

[pksunkara]

@logansquirel Did you get a chance to look at this? This might have already been fixed on master.

[logansquirel]

@logansquirel Did you get a chance to look at this? This might have already been fixed on master.

Cargo.toml:

[package]
name = "clap_issue_2009"
version = "0.1.0"
authors = ["Logan SQUIREL <logan.squirel@protonmail.com>"]
edition = "2018"

[dependencies]
clap = { git = "https://github.com/clap-rs/clap" }
clap_generate = { git = "https://github.com/clap-rs/clap" }

main.rs:

use clap::{Clap, FromArgMatches, IntoApp};
use clap_generate::{generate, generators::Bash};

#[derive(Clap)]
enum Command {
    Generate,
}

#[derive(Clap)]
struct Arguments {
    #[clap(subcommand)]
    command: Command,
}

fn main() {
    let mut app = Arguments::into_app();
    let Arguments { command: _c, } = Arguments::from_arg_matches(&app.get_matches_mut());
    let bin_name = app.get_bin_name().unwrap().to_owned();
    generate::<Bash, _>(&mut app, bin_name, &mut std::io::stdout());
}

Running:

❯ cargo run generate
_clap_issue_2009() {
    local i cur prev opts cmds
    COMPREPLY=()
    cur="${COMP_WORDS[COMP_CWORD]}"
    prev="${COMP_WORDS[COMP_CWORD-1]}"
    cmd=""
    opts=""

    for i in ${COMP_WORDS[@]}
    do
        case "${i}" in
            clap_issue_2009)
                cmd="clap_issue_2009"
                ;;

            generate)
                cmd+="__generate"
                ;;
            help)
                cmd+="__help"
                ;;
            *)
                ;;
        esac
    done

    case "${cmd}" in
        clap_issue_2009)
            opts=" -h -V  --help --version  generate help"
            if [[ ${cur} == -* || ${COMP_CWORD} -eq 1 ]] ; then
                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                return 0
            fi
            case "${prev}" in

                *)
                    COMPREPLY=()
                    ;;
            esac
            COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
            return 0
            ;;

        clap_issue_2009__generate)
            opts=" -h -V  --help --version  "
            if [[ ${cur} == -* || ${COMP_CWORD} -eq 2 ]] ; then
                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                return 0
            fi
            case "${prev}" in

                *)
                    COMPREPLY=()
                    ;;
            esac
            COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
            return 0
            ;;
        clap_issue_2009__help)
            opts=" -h -V  --help --version  "
            if [[ ${cur} == -* || ${COMP_CWORD} -eq 2 ]] ; then
                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                return 0
            fi
            case "${prev}" in

                *)
                    COMPREPLY=()
                    ;;
            esac
            COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
            return 0
            ;;
    esac
}

complete -F _clap_issue_2009 -o bashdefault -o default clap_issue_2009

This might have already been is fixed on master.