Clap doesn't parse correctly a YAML file if 2 spaces are used (for indent) instead of 4.

[Booteille]

Rust Version

• 1.17.0 (56124baa9 2017-04-24)

Affected Version of clap

• 2.24.2

Expected Behavior Summary

Clap should correctly handle YAML files where indents are made by 2 spaces instead of 4.

Actual Behavior Summary

Clap actually returns wrong output in this use case.

Steps to Reproduce the issue

Try to indent your file with 2 spaces instead of 4 and you should get a wrong result

Sample Code or Link to Sample Code

Here is the code i've written to test it:

name: Test
version: "v0.1.0"
author: Booteille
about: Test
subcommands:
  - server:
    about: server related commands

And the resulted output of cargo run -- -h:

Test v0.1.0
Booteille
Test

USAGE:
    blynkcli [SUBCOMMAND]

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information

SUBCOMMANDS:
    about    
    help     Prints this message or the help of the given subcommand(s)

Also, the output of cargo run -- server:

error: Found argument 'server' which wasn't expected, or isn't valid in this context

USAGE:
    blynkcli [SUBCOMMAND]

For more information try --help

Debug output

DEBUG:clap:Parser::add_subcommand: term_w=None, name=about
DEBUG:clap:Parser::propogate_settings: self=Test, g_settings=AppFlags(
    NEEDS_LONG_HELP | NEEDS_LONG_VERSION | NEEDS_SC_HELP | UTF8_NONE | COLOR_AUTO
)
DEBUG:clap:Parser::propogate_settings: sc=about, settings=AppFlags(
    NEEDS_LONG_HELP | NEEDS_LONG_VERSION | NEEDS_SC_HELP | UTF8_NONE | COLOR_AUTO
), g_settings=AppFlags(
    NEEDS_LONG_HELP | NEEDS_LONG_VERSION | NEEDS_SC_HELP | UTF8_NONE | COLOR_AUTO
)
DEBUG:clap:Parser::propogate_settings: self=about, g_settings=AppFlags(
    NEEDS_LONG_HELP | NEEDS_LONG_VERSION | NEEDS_SC_HELP | UTF8_NONE | COLOR_AUTO
)
DEBUG:clap:Parser::get_matches_with;
DEBUG:clap:Parser::create_help_and_version;
DEBUG:clap:Parser::create_help_and_version: Building --help
DEBUG:clap:Parser::create_help_and_version: Building --version
DEBUG:clap:Parser::create_help_and_version: Building help
DEBUG:clap:Parser::get_matches_with: Begin parsing '"server"' ([115, 101, 114, 118, 101, 114])
DEBUG:clap:Parser::is_new_arg: arg="server", Needs Val of=NotFound
DEBUG:clap:Parser::is_new_arg: Arg::allow_leading_hyphen(false)
DEBUG:clap:Parser::is_new_arg: probably value
DEBUG:clap:Parser::is_new_arg: starts_new_arg=false
DEBUG:clap:Parser::possible_subcommand: arg="server"
DEBUG:clap:Parser::get_matches_with: possible_sc=false, sc=None
DEBUG:clap:Parser::get_matches_with: Positional counter...1
DEBUG:clap:Parser::get_matches_with: Low index multiples...false
DEBUG:clap:usage::create_usage_with_title;
DEBUG:clap:usage::create_usage_no_title;
DEBUG:clap:usage::get_required_usage_from: reqs=[], extra=None
DEBUG:clap:usage::get_required_usage_from: after init desc_reqs=[]
DEBUG:clap:usage::get_required_usage_from: no more children
DEBUG:clap:usage::get_required_usage_from: final desc_reqs=[]
DEBUG:clap:usage::get_required_usage_from: args_in_groups=[]
DEBUG:clap:usage::needs_flags_tag;
DEBUG:clap:usage::needs_flags_tag:iter: f=hclap_help;
DEBUG:clap:usage::needs_flags_tag:iter: f=vclap_version;
DEBUG:clap:usage::needs_flags_tag: [FLAGS] not required
DEBUG:clap:usage::create_help_usage: usage=blynkcli [SUBCOMMAND]
DEBUG:clap:Parser::color;
DEBUG:clap:Parser::color: Color setting...Auto
DEBUG:clap:Colorizer::error;
DEBUG:clap:is_a_tty: stderr=true
DEBUG:clap:Colorizer::warning;
DEBUG:clap:is_a_tty: stderr=true
DEBUG:clap:Colorizer::good;
DEBUG:clap:is_a_tty: stderr=true

[kbknapp]

Thanks for taking the time to report this! This should get fixed "for free" upon the move to using serde which is an active work in progress 😄

[hoodie]

TL;DR: no bug, can be closed

1. I don't think a serde-yaml switch would fix this, since this appears to be a parser related problem and serde-yaml also only uses yaml-rust
2. this yaml example is quite ambiguous and other yaml parses (both included in ruby) interpret it in the same way

my comparison script:

#!/usr/bin/env ruby
require "yaml"
require 'psych'
require "pp"

puts $FILENAME

content11 =  "%YAML 1.1\n---\n#{ File.read $FILENAME}"

puts content11
pp YAML.load content11
pp Psych.load content11

content12 =  "%YAML 1.2\n---\n#{ File.read $FILENAME}"

begin
    pp YAML.load content12
rescue Psych::SyntaxError
    puts "syntax Error"
    puts $!
end

begin
    pp Psych.load content12
rescue Psych::SyntaxError
    puts "syntax Error"
    puts $!
end

your example + differently indented alternatives:

name: Test
version: "v0.1.0"
author: Booteille
about: Test
subcommands:
  - server:
    about: server related commands
subcommands2:
  - server:
      about: server related commands
subcommands3:
 - server:
    about: server related commands

and it's output:

{"name"=>"Test",
 "version"=>"v0.1.0",
 "author"=>"Booteille",
 "about"=>"Test",
 "subcommands"=>[{"server"=>nil, "about"=>"server related commands"}],
 "subcommands2"=>[{"server"=>{"about"=>"server related commands"}}],
 "subcommands3"=>[{"server"=>{"about"=>"server related commands"}}]}
{"name"=>"Test",
 "version"=>"v0.1.0",
 "author"=>"Booteille",
 "about"=>"Test",
 "subcommands"=>[{"server"=>nil, "about"=>"server related commands"}],
 "subcommands2"=>[{"server"=>{"about"=>"server related commands"}}],
 "subcommands3"=>[{"server"=>{"about"=>"server related commands"}}]}
...

so I would argue that is is just an issue of yaml being yaml, you are just not supposed to put the child object of server in the same column. I'd advice to just close this as wont-fix