Allow mash error silencing (#488)

8 files changed, 131 insertions, 77 deletions

diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index b3fa0d3..0590878 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,6 +1,6 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2019-08-13 23:33:30 -0400 using RuboCop version 0.52.1.
+# on 2019-10-10 00:07:29 -0400 using RuboCop version 0.52.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
@@ -14,6 +14,12 @@ Metrics/AbcSize:
 Metrics/CyclomaticComplexity:
   Max: 11
 
+# Offense count: 1
+# Configuration parameters: AllowHeredoc, AllowURI, URISchemes, IgnoreCopDirectives, IgnoredPatterns.
+# URISchemes: http, https
+Metrics/LineLength:
+  Max: 111
+
 # Offense count: 18
 # Configuration parameters: CountComments.
 Metrics/MethodLength:
@@ -23,6 +29,6 @@ Metrics/MethodLength:
 Metrics/PerceivedComplexity:
   Max: 10
 
-# Offense count: 39
+# Offense count: 41
 Style/Documentation:
   Enabled: false
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 56ac655..a2b2c37 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,7 +15,8 @@ scheme are considered to be bugs.
 * [#323](https://github.com/intridea/hashie/pull/323): Added `Hashie::Extensions::Mash::DefineAccessors` - [@marshall-lee](https://github.com/marshall-lee).
 * [#474](https://github.com/intridea/hashie/pull/474): Expose `YAML#safe_load` options in `Mash#load` - [@riouruma](https://github.com/riouruma), [@dblock](https://github.com/dblock).
 * [#478](https://github.com/intridea/hashie/pull/478): Added optional array parameter to `Hashie::Mash.disable_warnings` - [@bobbymcwho](https://github.com/bobbymcwho).
-* [#481](https://github.com/intridea/hashie/pull/481): Ruby 2.6 - Support Hash#merge and #merge! called with multiple Hashes/Mashes - [@bobbymcwho](https://github.com/bobbymcwho).
+* [#481](https://github.com/intridea/hashie/pull/481): Ruby 2.6 - Support `Hash#merge` and `#merge!` called with multiple Hashes/Mashes - [@bobbymcwho](https://github.com/bobbymcwho).
+* [#488](https://github.com/intridea/hashie/pull/488): Added ability to create an anonymous `Hashie::Mash` subclass with key conflict errors silenced using `Hashie::Mash.quiet.new` - [@bobbymcwho](https://github.com/bobbymcwho).
 * Your contribution here.
 
 ### Changed
diff --git a/README.md b/README.md
index 0a088dd..be94965 100644
--- a/README.md
+++ b/README.md
@@ -557,6 +557,13 @@ end
 Response.new(merge: 'true', compact: true, zip: '90210', zap: 'electric')
 ```
 
+If you would like to create an anonymous subclass of a Hashie::Mash with key conflict warnings disabled:
+
+```ruby
+Hashie::Mash.quiet.new(zip: '90210', compact: true) # no errors logged
+Hashie::Mash.quiet(:zip).new(zip: '90210', compact: true) # error logged for compact
+```
+
 ### How does the wrapping of Mash sub-Hashes work?
 
 Mash duplicates any sub-Hashes that you add to it and wraps them in a Mash. This allows for infinite chaining of nested Hashes within a Mash without modifying the object(s) that are passed into the Mash. When you subclass Mash, the subclass wraps any sub-Hashes in its own class. This preserves any extensions that you mixed into the Mash subclass and allows them to work within the sub-Hashes, in addition to the main containing Mash.
diff --git a/UPGRADING.md b/UPGRADING.md
index ce01eca..1374e10 100644
--- a/UPGRADING.md
+++ b/UPGRADING.md
@@ -36,10 +36,14 @@ p cool_parents
 
 This may make places where you had to re-make the Mash redundant, and may cause unintended side effects if your application was expecting a plain old ruby Hash.
 
-### Ruby 2.6: Mash#merge and Mash#merge!
+#### Ruby 2.6: Mash#merge and Mash#merge!
 
 In Ruby > 2.6.0, Hashie now supports passing multiple hash and Mash objects to Mash#merge and Mash#merge!.
 
+#### Hashie::Mash::CannotDisableMashWarnings error class is removed
+
+There shouldn't really be a case that anyone was relying on catching this specific error, but if so, they should change it to rescue Hashie::Extensions::KeyConflictWarning::CannotDisableMashWarnings
+
 ### Upgrading to 3.7.0
 
 #### Mash#load takes options
diff --git a/lib/hashie.rb b/lib/hashie.rb
index fd93e05..a3fc11c 100644
--- a/lib/hashie.rb
+++ b/lib/hashie.rb
@@ -12,26 +12,26 @@ module Hashie
   autoload :Utils,              'hashie/utils'
 
   module Extensions
-    autoload :Coercion,          'hashie/extensions/coercion'
-    autoload :DeepMerge,         'hashie/extensions/deep_merge'
-    autoload :IgnoreUndeclared,  'hashie/extensions/ignore_undeclared'
-    autoload :IndifferentAccess, 'hashie/extensions/indifferent_access'
-    autoload :MergeInitializer,  'hashie/extensions/merge_initializer'
-    autoload :MethodAccess,      'hashie/extensions/method_access'
-    autoload :MethodQuery,       'hashie/extensions/method_access'
-    autoload :MethodReader,      'hashie/extensions/method_access'
-    autoload :MethodWriter,      'hashie/extensions/method_access'
-    autoload :StringifyKeys,     'hashie/extensions/stringify_keys'
-    autoload :SymbolizeKeys,     'hashie/extensions/symbolize_keys'
-    autoload :DeepFetch,         'hashie/extensions/deep_fetch'
-    autoload :DeepFind,          'hashie/extensions/deep_find'
-    autoload :DeepLocate,        'hashie/extensions/deep_locate'
-    autoload :PrettyInspect,     'hashie/extensions/pretty_inspect'
-    autoload :KeyConversion,     'hashie/extensions/key_conversion'
+    autoload :Coercion,           'hashie/extensions/coercion'
+    autoload :DeepMerge,          'hashie/extensions/deep_merge'
+    autoload :IgnoreUndeclared,   'hashie/extensions/ignore_undeclared'
+    autoload :IndifferentAccess,  'hashie/extensions/indifferent_access'
+    autoload :MergeInitializer,   'hashie/extensions/merge_initializer'
+    autoload :MethodAccess,       'hashie/extensions/method_access'
+    autoload :MethodQuery,        'hashie/extensions/method_access'
+    autoload :MethodReader,       'hashie/extensions/method_access'
+    autoload :MethodWriter,       'hashie/extensions/method_access'
+    autoload :StringifyKeys,      'hashie/extensions/stringify_keys'
+    autoload :SymbolizeKeys,      'hashie/extensions/symbolize_keys'
+    autoload :DeepFetch,          'hashie/extensions/deep_fetch'
+    autoload :DeepFind,           'hashie/extensions/deep_find'
+    autoload :DeepLocate,         'hashie/extensions/deep_locate'
+    autoload :PrettyInspect,      'hashie/extensions/pretty_inspect'
+    autoload :KeyConversion,      'hashie/extensions/key_conversion'
     autoload :MethodAccessWithOverride, 'hashie/extensions/method_access'
-    autoload :StrictKeyAccess,   'hashie/extensions/strict_key_access'
-    autoload :RubyVersion,       'hashie/extensions/ruby_version'
-    autoload :RubyVersionCheck,  'hashie/extensions/ruby_version_check'
+    autoload :StrictKeyAccess,    'hashie/extensions/strict_key_access'
+    autoload :RubyVersion,        'hashie/extensions/ruby_version'
+    autoload :RubyVersionCheck,   'hashie/extensions/ruby_version_check'
 
     module Parsers
       autoload :YamlErbParser, 'hashie/extensions/parsers/yaml_erb_parser'
diff --git a/lib/hashie/extensions/key_conflict_warning.rb b/lib/hashie/extensions/key_conflict_warning.rb
new file mode 100644
index 0000000..7ce56a1
--- /dev/null
+++ b/lib/hashie/extensions/key_conflict_warning.rb
@@ -0,0 +1,55 @@
+module Hashie
+  module Extensions
+    module KeyConflictWarning
+      class CannotDisableMashWarnings < StandardError
+        def initialize
+          super(
+            'You cannot disable warnings on the base Mash class. ' \
+            'Please subclass the Mash and disable it in the subclass.'
+          )
+        end
+      end
+
+      # Disable the logging of warnings based on keys conflicting keys/methods
+      #
+      # @api semipublic
+      # @return [void]
+      def disable_warnings(*method_keys)
+        raise CannotDisableMashWarnings if self == Hashie::Mash
+        if method_keys.any?
+          disabled_warnings.concat(method_keys).tap(&:flatten!).uniq!
+        else
+          disabled_warnings.clear
+        end
+
+        @disable_warnings = true
+      end
+
+      # Checks whether this class disables warnings for conflicting keys/methods
+      #
+      # @api semipublic
+      # @return [Boolean]
+      def disable_warnings?(method_key = nil)
+        return disabled_warnings.include?(method_key) if disabled_warnings.any? && method_key
+        @disable_warnings ||= false
+      end
+
+      # Returns an array of blacklisted methods that this class disables warnings for.
+      #
+      # @api semipublic
+      # @return [Boolean]
+      def disabled_warnings
+        @_disabled_warnings ||= []
+      end
+
+      # Inheritance hook that sets class configuration when inherited.
+      #
+      # @api semipublic
+      # @return [void]
+      def inherited(subclass)
+        super
+        subclass.disable_warnings(disabled_warnings) if disable_warnings?
+      end
+    end
+  end
+end
diff --git a/lib/hashie/mash.rb b/lib/hashie/mash.rb
index 888b4f6..77a852f 100644
--- a/lib/hashie/mash.rb
+++ b/lib/hashie/mash.rb
@@ -2,6 +2,7 @@ require 'hashie/hash'
 require 'hashie/array'
 require 'hashie/utils'
 require 'hashie/logger'
+require 'hashie/extensions/key_conflict_warning'
 
 module Hashie
   # Mash allows you to create pseudo-objects that have method-like
@@ -62,59 +63,10 @@ module Hashie
   class Mash < Hash
     include Hashie::Extensions::PrettyInspect
     include Hashie::Extensions::RubyVersionCheck
+    extend Hashie::Extensions::KeyConflictWarning
 
     ALLOWED_SUFFIXES = %w[? ! = _].freeze
 
-    class CannotDisableMashWarnings < StandardError
-      def initialize
-        super(
-          'You cannot disable warnings on the base Mash class. ' \
-          'Please subclass the Mash and disable it in the subclass.'
-        )
-      end
-    end
-
-    # Disable the logging of warnings based on keys conflicting keys/methods
-    #
-    # @api semipublic
-    # @return [void]
-    def self.disable_warnings(*method_keys)
-      raise CannotDisableMashWarnings if self == Hashie::Mash
-      if method_keys.any?
-        disable_warnings_blacklist.concat(method_keys).tap(&:flatten!).uniq!
-      else
-        disable_warnings_blacklist.clear
-      end
-
-      @disable_warnings = true
-    end
-
-    # Checks whether this class disables warnings for conflicting keys/methods
-    #
-    # @api semipublic
-    # @return [Boolean]
-    def self.disable_warnings?(method_key = nil)
-      return disable_warnings_blacklist.include?(method_key) if disable_warnings_blacklist.any? && method_key
-      @disable_warnings ||= false
-    end
-
-    # Returns an array of blacklisted methods that this class disables warnings for.
-    #
-    # @api semipublic
-    # @return [Boolean]
-    def self.disable_warnings_blacklist
-      @_disable_warnings_blacklist ||= []
-    end
-
-    # Inheritance hook that sets class configuration when inherited.
-    #
-    # @api semipublic
-    # @return [void]
-    def self.inherited(subclass)
-      super
-      subclass.disable_warnings(disable_warnings_blacklist) if disable_warnings?
-    end
-
     def self.load(path, options = {})
       @_mashes ||= new
 
@@ -149,6 +101,20 @@ module Hashie
       default ? super(default) : super(&blk)
     end
 
+    # Creates a new anonymous subclass with key conflict
+    # warnings disabled. You may pass an array of method
+    # symbols to restrict the warnings blacklist to.
+    # Hashie::Mash.quiet.new(hash) all warnings disabled.
+    # Hashie::Mash.quiet(:zip).new(hash) only zip warning
+    # is disabled.
+    def self.quiet(*method_keys)
+      (@memoized_classes ||= {})[method_keys] ||
+        Class.new(self).tap do |k|
+          k.send(:disable_warnings, *method_keys)
+          @memoized_classes[method_keys] = k
+        end
+    end
+
     class << self; alias [] new; end
 
     alias regular_reader []
diff --git a/spec/hashie/mash_spec.rb b/spec/hashie/mash_spec.rb
index e2a178c..77a1c6b 100644
--- a/spec/hashie/mash_spec.rb
+++ b/spec/hashie/mash_spec.rb
@@ -160,7 +160,9 @@ describe Hashie::Mash do
     end
 
     it 'cannot disable logging on the base Mash' do
-      expect { Hashie::Mash.disable_warnings }.to raise_error(Hashie::Mash::CannotDisableMashWarnings)
+      expected_error = Hashie::Extensions::KeyConflictWarning::CannotDisableMashWarnings
+
+      expect { Hashie::Mash.disable_warnings }.to raise_error(expected_error)
     end
 
     it 'carries over the disable for warnings on grandchild classes' do
@@ -200,7 +202,7 @@ describe Hashie::Mash do
 
       grandchild_class.new('address' => { 'zip' => '90210' }, 'merge' => true)
 
-      expect(grandchild_class.disable_warnings_blacklist).to eq(%i[zip merge])
+      expect(grandchild_class.disabled_warnings).to eq(%i[zip merge])
       expect(logger_output).to be_blank
     end
 
@@ -213,7 +215,7 @@ describe Hashie::Mash do
             disable_warnings :cycle
           end
 
-          expect(child_class.disable_warnings_blacklist).to eq(%i[zip merge cycle])
+          expect(child_class.disabled_warnings).to eq(%i[zip merge cycle])
         end
       end
 
@@ -226,7 +228,7 @@ describe Hashie::Mash do
 
           child_class.new('address' => { 'zip' => '90210' }, 'merge' => true, 'cycle' => 'bi')
 
-          expect(child_class.disable_warnings_blacklist).to eq([])
+          expect(child_class.disabled_warnings).to eq([])
           expect(logger_output).to be_blank
         end
       end
@@ -962,6 +964,19 @@ describe Hashie::Mash do
     end
   end
 
+  describe '.quiet' do
+    it 'returns a subclass of the calling class' do
+      expect(Hashie::Mash.quiet.new).to be_a(Hashie::Mash)
+    end
+
+    it 'memoizes and returns classes' do
+      call_one = Hashie::Mash.quiet
+      call_two = Hashie::Mash.quiet
+      expect(Hashie::Mash.instance_variable_get('@memoized_classes').count).to eq(1)
+      expect(call_one).to eq(call_two)
+    end
+  end
+
   with_minimum_ruby('2.3.0') do
     describe '#dig' do
       subject { described_class.new(a: { b: 1 }) }