Globbing is broken when building from source

[iftheshoefritz]

Compare 7a4d6cf (just before the switch to clap) [globbing works]:

☁  complexity [7a4d6cf] cargo run -- --only src/**/*.rs
   Compiling complexity v0.4.2 (/Users/frederickmeissner/devprojects/complexity)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.31s
     Running `target/debug/complexity --only src/cli.rs src/configuration.rs src/files_filter.rs src/flags.rs src/lib.rs src/main.rs src/parsed_file.rs src/parser.rs src/scoring.rs src/scoring/length.rs src/scoring/standard.rs`
   16.55 ./src/cli.rs
    8.56 ./src/parser.rs
    0.67 ./src/main.rs
    6.17 ./src/scoring/length.rs
    6.78 ./src/scoring/standard.rs
    5.63 ./src/parsed_file.rs
   14.82 ./src/files_filter.rs
    5.06 ./src/configuration.rs
    0.11 ./src/lib.rs
   16.44 ./src/scoring.rs
    5.72 ./src/flags.rs

With ad3b (switch to clap) and later [globbing is broken]:

☁  complexity [ad3bf6a] cargo run -- --only **/*.rs
   Compiling complexity v0.4.2 (/Users/frederickmeissner/devprojects/complexity)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.64s
     Running `target/debug/complexity --only src/cli.rs src/configuration.rs src/files_filter.rs src/flags.rs src/lib.rs src/main.rs src/parsed_file.rs src/parser.rs src/scoring.rs src/scoring/length.rs src/scoring/standard.rs`
error: The subcommand 'src/configuration.rs' wasn't recognized

Usage: complexity [OPTIONS] [COMMAND]

For more information try '--help'

Happily the older commit is what homebrew installs by default, but I assume that there are reasons why we do want to use clap and it would be better to fix our use of clap rather than revert something else useful.

[iftheshoefritz]

It may be that globbing only worked by accident with structopt, but it would be cool to have, personally I use --only app/**/*.rb for analysing Rails apps a lot.

[neilvcarvalho]

I managed to mimic the structopt accidental behavior by allowing multiple arguments and setting ',' as a delimiter:

#[clap(long, num_args = 1.., value_delimiter = ',')]

Things get weird if you try something that can't be expanded, like:

complexity --only *.js,*.rb

Because you expect both globbing and comma-separated values to work.

I wonder if a separate flag would be a better fit for supporting multiple full paths like shell expansion would provide.

@joshuaclayton added some thoughts here: #24 (comment)