Bash completion for flags

[mabelzhang]

🎉 New feature

Part of gazebosim/gz-tools#1
Used together with gazebosim/gz-tools#87

Summary

Bash completion script for flags available to this subcommand.
This is a standalone function that depends on a new script in gazebosim/gz-tools#87 to call this.

Test it

After sourcing the dependent script in ign-tools, source the script in this PR:

. plugin.bash_completion.sh

If you just tab, you get the default system tab-completion that shows the files in the current directory:

$ ign plugin <tab>

If you type -, and then tab, you get the tab-completion for all the flags available for this subcommand:

$ ign plugin -<tab>
--help      --help-all  --info      --plugin    --verbose   --version   -h          -i          -p          -v          

Then you can type partial flags, and it'll do tab-completion normally for you, such as

$ ign plugin --help<tab>
--help      --help-all  

It also works for multiple flags, like ign plugin --<flag1> --<flag2> ...

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[mabelzhang]

I think the PR comments have been addressed.

[codecov]

Codecov Report

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@@              Coverage Diff               @@
##             ign-plugin1      #81   +/-   ##
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  Coverage               ?   99.82%           
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  Files                  ?       15           
  Lines                  ?      584           
  Branches               ?        0           
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  Hits                   ?      583           
  Misses                 ?        1           
  Partials               ?        0           

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[chapulina]

I pushed d69a07a to make sure we always install the CLI files, even if the ign tool isn't found during build time.

More context in:

• Remove ign-tools from CMakeLists.txt. Not used #56
• Find ign program instead of ignition-tools #57
• [tracker] Remove ignition-tools cmake check in Ignition software gazebo-tooling/release-tools#472