Add chef-utils gem with various recipe DSL helpers

This is the implementation of [RFC-087](https://github.com/chef-boneyard/chef-rfc/blob/master/rfc087-distro-sugar-helpers.md)
although some of the specifics have been iterated on and changed.

The documentation will be in the [README.md](https://github.com/chef/chef/tree/master/chef-utils/README.md) once this is merged.

While this PR mostly moves chef-sugar utilities into core-chef via this chef-utils gem, the scope of the chef-utils gem
should be considered larger than just that. As an example this PR moves the Mash class into this gem for reuse in ohai
as well.

Signed-off-by: Lamont Granquist <lamont@scriptkiddie.org>

1 files changed, 21 insertions, 232 deletions

diff --git a/lib/chef/mash.rb b/lib/chef/mash.rb
index 404d6d622f..64adfa8672 100644
--- a/lib/chef/mash.rb
+++ b/lib/chef/mash.rb
@@ -1,232 +1,21 @@
-# Copyright 2009-2016, Dan Kubb
-
-# Permission is hereby granted, free of charge, to any person obtaining
-# a copy of this software and associated documentation files (the
-# "Software"), to deal in the Software without restriction, including
-# without limitation the rights to use, copy, modify, merge, publish,
-# distribute, sublicense, and/or sell copies of the Software, and to
-# permit persons to whom the Software is furnished to do so, subject to
-# the following conditions:
-
-# The above copyright notice and this permission notice shall be
-# included in all copies or substantial portions of the Software.
-
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
-# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
-# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
-# ---
-# ---
-
-# Some portions of blank.rb and mash.rb are verbatim copies of software
-# licensed under the MIT license. That license is included below:
-
-# Copyright 2005-2016, David Heinemeier Hansson
-
-# Permission is hereby granted, free of charge, to any person obtaining
-# a copy of this software and associated documentation files (the
-# "Software"), to deal in the Software without restriction, including
-# without limitation the rights to use, copy, modify, merge, publish,
-# distribute, sublicense, and/or sell copies of the Software, and to
-# permit persons to whom the Software is furnished to do so, subject to
-# the following conditions:
-
-# The above copyright notice and this permission notice shall be
-# included in all copies or substantial portions of the Software.
-
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
-# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
-# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
-# This class has dubious semantics and we only have it so that people can write
-# params[:key] instead of params['key'].
-class Mash < Hash
-
-  # @param constructor<Object>
-  #   The default value for the mash. Defaults to an empty hash.
-  #
-  # @details [Alternatives]
-  #   If constructor is a Hash, a new mash will be created based on the keys of
-  #   the hash and no default value will be set.
-  def initialize(constructor = {})
-    if constructor.is_a?(Hash)
-      super()
-      update(constructor)
-    else
-      super(constructor)
-    end
-  end
-
-  # @param orig<Object> Mash being copied
-  #
-  # @return [Object] A new copied Mash
-  def initialize_copy(orig)
-    super
-    # Handle nested values
-    each do |k, v|
-      if v.is_a?(Mash) || v.is_a?(Array)
-        self[k] = v.dup
-      end
-    end
-    self
-  end
-
-  # @param key<Object> The default value for the mash. Defaults to nil.
-  #
-  # @details [Alternatives]
-  #   If key is a Symbol and it is a key in the mash, then the default value will
-  #   be set to the value matching the key.
-  def default(key = nil)
-    if key.is_a?(Symbol) && include?(key = key.to_s)
-      self[key]
-    else
-      super
-    end
-  end
-
-  alias_method :regular_writer, :[]= unless method_defined?(:regular_writer)
-  alias_method :regular_update, :update unless method_defined?(:regular_update)
-
-  # @param key<Object> The key to set.
-  # @param value<Object>
-  #   The value to set the key to.
-  #
-  # @see Mash#convert_key
-  # @see Mash#convert_value
-  def []=(key, value)
-    regular_writer(convert_key(key), convert_value(value))
-  end
-
-  # internal API for use by Chef's deep merge cache
-  # @api private
-  def internal_set(key, value)
-    regular_writer(key, convert_value(value))
-  end
-
-  # @param other_hash<Hash>
-  #   A hash to update values in the mash with. The keys and the values will be
-  #   converted to Mash format.
-  #
-  # @return [Mash] The updated mash.
-  def update(other_hash)
-    other_hash.each_pair { |key, value| regular_writer(convert_key(key), convert_value(value)) }
-    self
-  end
-
-  alias_method :merge!, :update
-
-  # @param key<Object> The key to check for. This will be run through convert_key.
-  #
-  # @return [Boolean] True if the key exists in the mash.
-  def key?(key)
-    super(convert_key(key))
-  end
-
-  # def include? def has_key? def member?
-  alias_method :include?, :key?
-  alias_method :has_key?, :key?
-  alias_method :member?, :key?
-
-  # @param key<Object> The key to fetch. This will be run through convert_key.
-  # @param *extras<Array> Default value.
-  #
-  # @return [Object] The value at key or the default value.
-  def fetch(key, *extras)
-    super(convert_key(key), *extras)
-  end
-
-  # @param *indices<Array>
-  #   The keys to retrieve values for. These will be run through +convert_key+.
-  #
-  # @return [Array] The values at each of the provided keys
-  def values_at(*indices)
-    indices.collect { |key| self[convert_key(key)] }
-  end
-
-  # @param hash<Hash> The hash to merge with the mash.
-  #
-  # @return [Mash] A new mash with the hash values merged in.
-  def merge(hash)
-    dup.update(hash)
-  end
-
-  # @param key<Object>
-  #   The key to delete from the mash.\
-  def delete(key)
-    super(convert_key(key))
-  end
-
-  # @param *rejected<Array[(String, Symbol)] The mash keys to exclude.
-  #
-  # @return [Mash] A new mash without the selected keys.
-  #
-  # @example
-  #   { :one => 1, :two => 2, :three => 3 }.except(:one)
-  #     #=> { "two" => 2, "three" => 3 }
-  def except(*keys)
-    super(*keys.map { |k| convert_key(k) })
-  end
-
-  # Used to provide the same interface as Hash.
-  #
-  # @return [Mash] This mash unchanged.
-  def stringify_keys!; self end
-
-  # @return [Hash] The mash as a Hash with symbolized keys.
-  def symbolize_keys
-    h = Hash.new(default)
-    each { |key, val| h[key.to_sym] = val }
-    h
-  end
-
-  # @return [Hash] The mash as a Hash with string keys.
-  def to_hash
-    Hash.new(default).merge(self)
-  end
-
-  # @return [Mash] Convert a Hash into a Mash
-  # The input Hash's default value is maintained
-  def self.from_hash(hash)
-    mash = Mash.new(hash)
-    mash.default = hash.default
-    mash
-  end
-
-  protected
-
-  # @param key<Object> The key to convert.
-  #
-  # @param [Object]
-  #   The converted key. If the key was a symbol, it will be converted to a
-  #   string.
-  #
-  # @api private
-  def convert_key(key)
-    key.is_a?(Symbol) ? key.to_s : key
-  end
-
-  # @param value<Object> The value to convert.
-  #
-  # @return [Object]
-  #   The converted value. A Hash or an Array of hashes, will be converted to
-  #   their Mash equivalents.
-  #
-  # @api private
-  def convert_value(value)
-    if value.class == Hash
-      Mash.from_hash(value)
-    elsif value.is_a?(Array)
-      value.collect { |e| convert_value(e) }
-    else
-      value
-    end
-  end
-end
+#
+# Copyright:: Copyright 2018-2019, Chef Software Inc.
+# 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-utils/mash" unless defined?(ChefUtils::Mash)
+
+# For historical reasons we inject Mash directly into the top level class namespace
+Mash = ChefUtils::Mash unless defined?(Mash)