Handle empty array of ignores in yaml file

[jasonkarns]

Description

I'm attempting to validate that the current ignore patterns in .bundler-audit.yml are still valid.

I began with a yaml file that looked like this:

---
ignore:
  - CVE-...
  - CVE-...

And then commented out the ignores:

---
ignore:
  # - CVE-...
  # - CVE-...

But then bundler-audit failed to load the file entirely:

$ rake bundler:audit
/opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/configuration.rb:72:in 'block in Bundler::Audit::Configuration.load': 'ignore' key found in config file, but is not an Array (Bundler::Audit::Configuration::InvalidConfigurationError)
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/configuration.rb:68:in 'Array#each'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/configuration.rb:68:in 'Enumerable#each_slice'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/configuration.rb:68:in 'Bundler::Audit::Configuration.load'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/scanner.rb:92:in 'Bundler::Audit::Scanner#initialize'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/cli.rb:70:in 'Class#new'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/cli.rb:70:in 'Bundler::Audit::CLI#check'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/thor-1.5.0/lib/thor/command.rb:28:in 'Thor::Command#run'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/thor-1.5.0/lib/thor/invocation.rb:127:in 'Thor::Invocation#invoke_command'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/thor-1.5.0/lib/thor.rb:538:in 'Thor.dispatch'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/thor-1.5.0/lib/thor/base.rb:585:in 'Thor::Base::ClassMethods#start'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/bin/bundle-audit:10:in '<top (required)>'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/bin/bundler-audit:3:in 'Kernel#load'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/bin/bundler-audit:3:in '<top (required)>'
	from /opt/rbenv/versions/3.4.8/lib/ruby/site_ruby/3.4.0/rubygems.rb:304:in 'Kernel#load'
	from /opt/rbenv/versions/3.4.8/lib/ruby/site_ruby/3.4.0/rubygems.rb:304:in 'Gem.activate_and_load_bin_path'
	from /opt/rbenv/versions/3.4.8/bin/bundler-audit:25:in '<main>'

Proceeding to comment out the entire ignore stanza also failed:

$ rake bundler:audit
/opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/configuration.rb:59:in 'Bundler::Audit::Configuration.load': Configuration found in '/Users/jasonkarns/Projects/sundaysfordogs/sundays/.bundler-audit.yml' is not YAML (Bundler::Audit::Configuration::InvalidConfigurationError)
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/scanner.rb:92:in 'Bundler::Audit::Scanner#initialize'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/cli.rb:70:in 'Class#new'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/lib/bundler/audit/cli.rb:70:in 'Bundler::Audit::CLI#check'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/thor-1.5.0/lib/thor/command.rb:28:in 'Thor::Command#run'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/thor-1.5.0/lib/thor/invocation.rb:127:in 'Thor::Invocation#invoke_command'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/thor-1.5.0/lib/thor.rb:538:in 'Thor.dispatch'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/thor-1.5.0/lib/thor/base.rb:585:in 'Thor::Base::ClassMethods#start'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/bin/bundle-audit:10:in '<top (required)>'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/bin/bundler-audit:3:in 'Kernel#load'
	from /opt/rbenv/versions/3.4.8/lib/ruby/gems/3.4.0/gems/bundler-audit-0.9.3/bin/bundler-audit:3:in '<top (required)>'
	from /opt/rbenv/versions/3.4.8/lib/ruby/site_ruby/3.4.0/rubygems.rb:304:in 'Kernel#load'
	from /opt/rbenv/versions/3.4.8/lib/ruby/site_ruby/3.4.0/rubygems.rb:304:in 'Gem.activate_and_load_bin_path'
	from /opt/rbenv/versions/3.4.8/bin/bundler-audit:25:in '<main>'

It would be nice if the yaml parsing was able to recognize "empty" as a valid input to allow simple and temporary commenting-out of ignore patterns.