save this as ~/.chef/plugins/knife/cookbook_test.rb and it will be used by 'knife cookbook test'

cookbook_test.rb

# NOTE: The foodcritic args option (--lint-args) has not been tested
#
# Author:: Adam Jacob (<adam@opscode.com>)
# Author:: Matthew Kent (<mkent@magoazul.com>)
# Author:: Joshua Timberman (<joshua@opscode.com>)
# Copyright:: Copyright (c) 2009-2012 Opscode, Inc.
# Copyright:: Copyright (c) 2010 Matthew Kent
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
require 'chef/knife'

module KnifePlugins
  class Knife
    class CookbookTest < Chef::Knife

      deps do
        require 'chef/checksum_cache'
        require 'chef/cookbook/syntax_check'
        include Chef::Mixin::ShellOut
      end

      banner "knife cookbook test [COOKBOOKS...] (options)"

      option :cookbook_path,
      :short => "-o PATH:PATH",
      :long => "--cookbook-path PATH:PATH",
      :description => "A colon-separated path to look for cookbooks in",
      :proc => lambda { |o| o.split(":") }

      option :all,
      :short => "-a",
      :long => "--all",
      :description => "Test all cookbooks, rather than just a single cookbook"

      option :foodcritic,
      :short => "-L",
      :long => "--lint",
      :description => "Include lint testing (foodcritic)",
      :default => false

      option :foodcritic_args,
      :long => "--lint-args",
      :description => "Comma-separated string of options to pass into lint tester (foodcritic)",
      :default => nil

      def run
        config[:cookbook_path] ||= Chef::Config[:cookbook_path]

        checked_a_cookbook = false
        if config[:all]
          cookbook_loader.each do |key, cookbook|
            checked_a_cookbook = true
            test_cookbook(key)
          end
        else
          @name_args.each do |cb|
            puts "checking #{cb}"
            next unless cookbook_loader.cookbook_exists?(cb)
            checked_a_cookbook = true
            test_cookbook(cb)
          end
        end
        unless checked_a_cookbook
          ui.warn("No cookbooks to test in #{Array(config[:cookbook_path]).join(',')} - is your cookbook path misconfigured?")
        end
      end

      def test_cookbook(cookbook)
        ui.info("Running syntax check on #{cookbook}")
        Array(config[:cookbook_path]).reverse.each do |path|
          syntax_checker = Chef::Cookbook::SyntaxCheck.for_cookbook(cookbook, path)
          test_ruby(syntax_checker)
          test_templates(syntax_checker)
          test_lint(cookbook) if config[:foodcritic]
        end
      end

      def test_ruby(syntax_checker)
        ui.info("Validating ruby files")
        exit(1) unless syntax_checker.validate_ruby_files
      end

      def test_templates(syntax_checker)
        ui.info("Validating templates")
        exit(1) unless syntax_checker.validate_templates
      end

      def test_lint(cookbook)
        lint_target = File.join(config[:cookbook_path], cookbook)
        ui.info("Running lint check on #{cookbook}")
        foodcritic_args = lint_args(config[:foodcritic_args]) if config[:foodcritic_args]
        result = shell_out("sh -c 'foodcritic #{foodcritic_args} #{lint_target}'")
        result.stdout.each_line {|l| ui.info(l)}
        result.error!
        true
      rescue Mixlib::ShellOut::ShellCommandFailed
        ui.fatal("Could not execute lint checker \`foodcritic\`")
        ui.fatal("Try installing the \`foodcritic\` gem and try again")
        result.stderr.each_line {|l| ui.fatal(l.chomp)}
        false
      end

      def lint_args(foodcritic_args)
        foodcritic_args.split(/,/).join(" ")
      end

      def cookbook_loader
        @cookbook_loader ||= Chef::CookbookLoader.new(config[:cookbook_path])
      end

    end
  end
end

This looks awesome. Thanks Joshua.

Commas can be used when specifying foodcritic rules to apply so we might want to use a different delimiter for lint-args.

Cheers,

Andrew.