From 8aaa28b37ad2afc202be510da97c5f4ab0dda473 Mon Sep 17 00:00:00 2001
From: Gabriel Nagy <gabrielnagy@me.com>
Date: Wed, 7 Aug 2024 13:03:10 +0300
Subject: [PATCH 1/3] Allow initializing enummer with hash

Similar to the Rails `enum` behavior, allow initializing an `enummer`
with a hash where the values correspond to the indices of the bits that
map to the flag.

This is a more robust and backwards-compatible approach to enums, as the
developer doesn't have to worry about migrating historical data if an
enum value is removed.
---
 README.md                     | 12 ++++++++++++
 lib/enummer/enummer_type.rb   | 21 ++++++---------------
 lib/enummer/extension.rb      | 22 ++++++++++++++--------
 test/dummy/app/models/user.rb |  6 +++++-
 test/enummer_test.rb          |  5 +++--
 5 files changed, 40 insertions(+), 26 deletions(-)

diff --git a/README.md b/README.md
index e36972c..0b4ce6d 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,18 @@ Now set up enummer with the available values in your model:
 enummer permissions: %i[read write execute]
 ```
 
+Similar to `enum`, enummer can also be initialized with a hash, where the numeric index represents the position of the bit that maps to the flag:
+
+``` ruby
+enummer permissions: {
+  read: 0,
+  write: 1,
+  execute: 2
+}
+```
+
+This makes it easier to add/remove entries without worrying about migrating historical data.
+
 ### Scopes
 
 Scopes will now be provided for `<option>` and `not_<option>`.
diff --git a/lib/enummer/enummer_type.rb b/lib/enummer/enummer_type.rb
index 97d30da..c05db9d 100644
--- a/lib/enummer/enummer_type.rb
+++ b/lib/enummer/enummer_type.rb
@@ -4,17 +4,16 @@
 
 module Enummer
   class EnummerType < ::ActiveRecord::Type::Value
-    # @param [Array<Symbol>] value_names list of all possible values for this type
-    def initialize(value_names:)
-      @value_names = value_names
-      @bit_pairs = determine_bit_pairs(value_names)
+    # @param [Array<Symbol>] values hash with bit-value pairs for all possible values for this type
+    def initialize(values:)
+      @values = values
     end
 
     # @return Symbol Representation of this type
     # @example
     #   :enummer[read|write|execute]
     def type
-      "enummer[#{@value_names.join("|")}]".to_sym
+      :"enummer[#{@values.keys.join("|")}]"
     end
 
     # @param [Symbol|Array<Symbol>] value Current value represented as one or more symbols
@@ -22,7 +21,7 @@ def type
     def serialize(value)
       return unless value
 
-      Array.wrap(value).sum { |value_name| @bit_pairs.fetch(value_name.to_sym, 0) }
+      Array.wrap(value).sum { |value_name| @values.fetch(value_name.to_sym, 0) }
     end
 
     # @param [Numeric] value Numeric representation of values
@@ -31,19 +30,11 @@ def deserialize(value)
       return [] unless value
       return [] if value.to_i.zero?
 
-      @bit_pairs.each_with_object([]) do |(pair_name, pair_value), value_names|
+      @values.each_with_object([]) do |(pair_name, pair_value), value_names|
         next if (value & pair_value).zero?
 
         value_names << pair_name
       end
     end
-
-    private
-
-    def determine_bit_pairs(value_names)
-      value_names.map.with_index do |name, shift|
-        [name, 1 << shift]
-      end.to_h
-    end
   end
 end
diff --git a/lib/enummer/extension.rb b/lib/enummer/extension.rb
index c215e3c..be6931f 100644
--- a/lib/enummer/extension.rb
+++ b/lib/enummer/extension.rb
@@ -13,10 +13,11 @@ def enummer(values)
       options[:_suffix] = values.delete(:_suffix)
 
       name, values = values.first
+      values = _enummer_determine_bit_pairs(values)
 
-      attribute(name, :enummer, value_names: values)
+      attribute(name, :enummer, values: values)
 
-      singleton_class.__send__(:define_method, name) { values }
+      singleton_class.__send__(:define_method, name) { values.keys }
 
       _enummer_build_with_scope(name, values)
       _enummer_build_values(name, values, options)
@@ -24,16 +25,16 @@ def enummer(values)
 
     private
 
-    def _enummer_build_with_scope(attribute_name, value_names)
+    def _enummer_build_with_scope(attribute_name, values)
       scope "with_#{attribute_name}", lambda { |desired|
-        expected = Array.wrap(desired).sum(0) { |value| 1 << value_names.index(value.to_sym) }
+        expected = Array.wrap(desired).sum(0) { |value| values[value.to_sym] }
 
         where("#{attribute_name} & :expected = :expected", expected: expected)
       }
     end
 
-    def _enummer_build_values(attribute_name, value_names, options)
-      value_names.each_with_index do |name, i|
+    def _enummer_build_values(attribute_name, values, options)
+      values.each do |name, bit|
         method_name = _enummer_method_name(attribute_name, name, options)
 
         define_method("#{method_name}?") { self[attribute_name].include?(name) }
@@ -49,8 +50,6 @@ def _enummer_build_values(attribute_name, value_names, options)
           update(attribute_name => self[attribute_name] + [name])
         end
 
-        bit = 1 << i
-
         scope method_name, -> { where("#{attribute_name} & :bit = :bit", bit: bit) }
         scope "not_#{method_name}", -> { where("#{attribute_name} & :bit != :bit", bit: bit) }
       end
@@ -69,5 +68,12 @@ def _enummer_affix(attribute_name, value)
 
       value
     end
+
+    def _enummer_determine_bit_pairs(values)
+      values = values.map.with_index { |value, i| [value, i] }.to_h if values.is_a?(Array)
+      values.transform_values do |shift|
+        1 << shift
+      end
+    end
   end
 end
diff --git a/test/dummy/app/models/user.rb b/test/dummy/app/models/user.rb
index 7788057..b01e9b7 100644
--- a/test/dummy/app/models/user.rb
+++ b/test/dummy/app/models/user.rb
@@ -4,7 +4,11 @@ class User < ApplicationRecord
   enummer permissions: %i[read write execute]
 
   enummer facial_features: %i[nose mouth eyes], _prefix: true
-  enummer diets: %i[cigarettes alcohol greens], _prefix: "consumes"
+  enummer diets: {
+            alcohol: 1,
+            cigarettes: 0,
+            greens: 2
+          }, _prefix: "consumes"
 
   enummer transport: %i[car truck submarine], _suffix: true
   enummer home: %i[box apartment house], _suffix: "home"
diff --git a/test/enummer_test.rb b/test/enummer_test.rb
index 5130d45..7c77d64 100644
--- a/test/enummer_test.rb
+++ b/test/enummer_test.rb
@@ -9,7 +9,7 @@ def setup
       diets: %i[cigarettes alcohol],
       transport: %i[submarine],
       home: %i[box])
-    @user2 = User.new(permissions: %i[read write])
+    @user2 = User.new(permissions: %i[read write], diets: %i[cigarettes])
     @user3 = User.new(permissions: %i[execute])
 
     [@user1, @user2, @user3].map { |user| user.save && user.reload }
@@ -33,6 +33,7 @@ def setup
     assert_equal [@user1], User.with_permissions(%i[execute read write])
     assert_equal [@user1], User.with_permissions(%w[execute read write])
     assert_equal [@user1, @user2], User.with_permissions(['read', :write])
+    assert_equal [@user1, @user2], User.with_diets(%i[cigarettes])
   end
 
   test "not scopes return users without those bits set" do
@@ -106,7 +107,7 @@ def setup
   end
 
   test "recognizes boolean params" do
-    @user1.update!(ActionController::Parameters.new({"consumes_cigarettes"=>"false"}).permit(:consumes_cigarettes))
+    @user1.update!(ActionController::Parameters.new({"consumes_cigarettes" => "false"}).permit(:consumes_cigarettes))
     refute @user1.consumes_cigarettes?
   end
 

From 007a36f4a663eb42f35ca00791eac2207da8f4a5 Mon Sep 17 00:00:00 2001
From: Gabriel Nagy <gabrielnagy@me.com>
Date: Wed, 7 Aug 2024 13:08:17 +0300
Subject: [PATCH 2/3] Fix all standardrb offences

---
 Gemfile                                                |  2 +-
 enummer.gemspec                                        |  2 +-
 lib/enummer/extension.rb                               |  6 +++---
 lib/tasks/enummer_tasks.rake                           |  1 +
 test/dummy/app/models/user.rb                          |  8 ++++----
 .../config/initializers/content_security_policy.rb     |  1 +
 test/dummy/config/initializers/inflections.rb          |  1 +
 test/dummy/config/initializers/permissions_policy.rb   |  1 +
 test/dummy/db/schema.rb                                |  2 --
 test/enummer_test.rb                                   |  2 +-
 test/test_helper.rb                                    | 10 +++++-----
 11 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/Gemfile b/Gemfile
index 6c24393..48a74cf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -15,5 +15,5 @@ group :test do
   gem "sqlite3", "~> 1.4"
   gem "mysql2"
   gem "simplecov", require: false
-  gem 'simplecov-cobertura', require: false
+  gem "simplecov-cobertura", require: false
 end
diff --git a/enummer.gemspec b/enummer.gemspec
index 2499a59..e758910 100644
--- a/enummer.gemspec
+++ b/enummer.gemspec
@@ -20,6 +20,6 @@ Gem::Specification.new do |spec|
     Dir["{app,config,db,lib}/**/*", "MIT-LICENSE", "Rakefile", "README.md"]
   end
 
-  spec.required_ruby_version = '>= 2.7'
+  spec.required_ruby_version = ">= 2.7"
   spec.add_dependency "rails", ">= 7.0.0"
 end
diff --git a/lib/enummer/extension.rb b/lib/enummer/extension.rb
index be6931f..e1c881b 100644
--- a/lib/enummer/extension.rb
+++ b/lib/enummer/extension.rb
@@ -37,8 +37,8 @@ def _enummer_build_values(attribute_name, values, options)
       values.each do |name, bit|
         method_name = _enummer_method_name(attribute_name, name, options)
 
-        define_method("#{method_name}?") { self[attribute_name].include?(name) }
-        define_method("#{method_name}=") do |new_value|
+        define_method(:"#{method_name}?") { self[attribute_name].include?(name) }
+        define_method(:"#{method_name}=") do |new_value|
           if ActiveModel::Type::Boolean.new.cast(new_value)
             self[attribute_name] += [name]
           else
@@ -46,7 +46,7 @@ def _enummer_build_values(attribute_name, values, options)
           end
           self[attribute_name].uniq!
         end
-        define_method("#{method_name}!") do
+        define_method(:"#{method_name}!") do
           update(attribute_name => self[attribute_name] + [name])
         end
 
diff --git a/lib/tasks/enummer_tasks.rake b/lib/tasks/enummer_tasks.rake
index 03ebd15..e2e18d1 100644
--- a/lib/tasks/enummer_tasks.rake
+++ b/lib/tasks/enummer_tasks.rake
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # desc "Explaining what the task does"
 # task :enummer do
 #   # Task goes here
diff --git a/test/dummy/app/models/user.rb b/test/dummy/app/models/user.rb
index b01e9b7..74b2757 100644
--- a/test/dummy/app/models/user.rb
+++ b/test/dummy/app/models/user.rb
@@ -5,10 +5,10 @@ class User < ApplicationRecord
 
   enummer facial_features: %i[nose mouth eyes], _prefix: true
   enummer diets: {
-            alcohol: 1,
-            cigarettes: 0,
-            greens: 2
-          }, _prefix: "consumes"
+    alcohol: 1,
+    cigarettes: 0,
+    greens: 2
+  }, _prefix: "consumes"
 
   enummer transport: %i[car truck submarine], _suffix: true
   enummer home: %i[box apartment house], _suffix: "home"
diff --git a/test/dummy/config/initializers/content_security_policy.rb b/test/dummy/config/initializers/content_security_policy.rb
index f37ed8d..96bd222 100644
--- a/test/dummy/config/initializers/content_security_policy.rb
+++ b/test/dummy/config/initializers/content_security_policy.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Define an application-wide content security policy
diff --git a/test/dummy/config/initializers/inflections.rb b/test/dummy/config/initializers/inflections.rb
index 6c78420..9e049dc 100644
--- a/test/dummy/config/initializers/inflections.rb
+++ b/test/dummy/config/initializers/inflections.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Add new inflection rules using the following format. Inflections
diff --git a/test/dummy/config/initializers/permissions_policy.rb b/test/dummy/config/initializers/permissions_policy.rb
index 50bcf4e..810aade 100644
--- a/test/dummy/config/initializers/permissions_policy.rb
+++ b/test/dummy/config/initializers/permissions_policy.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 # Define an application-wide HTTP permissions policy. For further
 # information see https://developers.google.com/web/updates/2018/06/feature-policy
 #
diff --git a/test/dummy/db/schema.rb b/test/dummy/db/schema.rb
index 7c6458f..fcd0c18 100644
--- a/test/dummy/db/schema.rb
+++ b/test/dummy/db/schema.rb
@@ -11,7 +11,6 @@
 # It's strongly recommended that you check this file into your version control system.
 
 ActiveRecord::Schema.define(version: 2022_01_30_163927) do
-
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -22,5 +21,4 @@
     t.integer "transport"
     t.integer "home"
   end
-
 end
diff --git a/test/enummer_test.rb b/test/enummer_test.rb
index 7c77d64..3c1e81b 100644
--- a/test/enummer_test.rb
+++ b/test/enummer_test.rb
@@ -32,7 +32,7 @@ def setup
   test "with_ scope returns users with all of those bits set" do
     assert_equal [@user1], User.with_permissions(%i[execute read write])
     assert_equal [@user1], User.with_permissions(%w[execute read write])
-    assert_equal [@user1, @user2], User.with_permissions(['read', :write])
+    assert_equal [@user1, @user2], User.with_permissions(["read", :write])
     assert_equal [@user1, @user2], User.with_diets(%i[cigarettes])
   end
 
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 13dfd5c..2c682a6 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -1,17 +1,17 @@
 # frozen_string_literal: true
 
-require 'simplecov'
+require "simplecov"
 SimpleCov.start do
   enable_coverage :branch
-  add_filter '/test/dummy/'
+  add_filter "/test/dummy/"
 
-  if ENV['CI']
-    require 'simplecov-cobertura'
+  if ENV["CI"]
+    require "simplecov-cobertura"
     SimpleCov.formatter = SimpleCov::Formatter::CoberturaFormatter
   end
 end
 
-  # Configure Rails Environment
+# Configure Rails Environment
 ENV["RAILS_ENV"] = "test"
 
 require_relative "../test/dummy/config/environment"

From b051e9ef635aedfd1fc75de1ec4e209b204d76a8 Mon Sep 17 00:00:00 2001
From: Gabriel Nagy <gabrielnagy@me.com>
Date: Thu, 29 Aug 2024 14:31:22 +0300
Subject: [PATCH 3/3] Always cast enummer values to symbols

Support for using strings as setters was added in 441cdf6, but the
initial implementation suffers from an idempotency issue, as changes
would be committed to the DB even if the values were the same. Consider
the following scenario:

    u = User.last
    => #<User:0x00007c747d137810 id: 3, permissions: [:read, :write], facial_features: [], diets: [], transport: [], home: []>

    u.permissions = u.permissions.map(&:to_s)
    => ["read", "write"]

    u.changes
    => {"permissions"=>[[:read, :write], ["read", "write"]]}

Because we cast the values to symbols when serializing, we set the
correct bitmask but this comes with the drawback of altering the DB
even if the new values are the same.

A better way to handle this issue is to delegate the responsibility to
the `cast` method. If we do this we can drop the initial fix, as values
will _always_ be symbols.

It's tricky to test something like this, so I've opted to hook into
ActiveRecord notifications and confirm no SQL UPDATE is being triggered
if the values are the same.
---
 lib/enummer/enummer_type.rb |  8 +++++++-
 test/enummer_test.rb        | 11 ++++++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/lib/enummer/enummer_type.rb b/lib/enummer/enummer_type.rb
index c05db9d..d39e761 100644
--- a/lib/enummer/enummer_type.rb
+++ b/lib/enummer/enummer_type.rb
@@ -21,7 +21,7 @@ def type
     def serialize(value)
       return unless value
 
-      Array.wrap(value).sum { |value_name| @values.fetch(value_name.to_sym, 0) }
+      Array.wrap(value).sum { |value_name| @values.fetch(value_name, 0) }
     end
 
     # @param [Numeric] value Numeric representation of values
@@ -36,5 +36,11 @@ def deserialize(value)
         value_names << pair_name
       end
     end
+
+    # @param [Array<Symbol>] value Current value represented as one or more symbols or strings
+    # @return [Array<Symbol>] Current value represented as symbols
+    def cast(value)
+      Array.wrap(value).map(&:to_sym)
+    end
   end
 end
diff --git a/test/enummer_test.rb b/test/enummer_test.rb
index 3c1e81b..3c7d8f2 100644
--- a/test/enummer_test.rb
+++ b/test/enummer_test.rb
@@ -77,9 +77,18 @@ def setup
   end
 
   test "setting the attribute with strings adds the values" do
-    @user3.update(permissions: ["read", "write"])
+    @user3.update(permissions: %w[read write])
 
     assert_equal %i[read write], @user3.permissions
+
+    updated = false
+    callback = lambda { |_name, _start, _finish, _id, payload| updated = true if payload[:sql].starts_with?("UPDATE") }
+
+    ActiveSupport::Notifications.subscribed(callback, "sql.active_record") do
+      @user3.update(permissions: %w[read write])
+    end
+
+    refute updated, "subsequent updates with the same values should be idempotent"
   end
 
   test "using a bang method properly updates the persisted field" do