Add configuration options to control to_key and to_param overrides

This allows users to disable Identifiable's overriding of Rails' to_key and to_param methods, which can break compatibility with other gems like Devise. Both options default to true to maintain backward compatibility.

Author: tpritc

README.md

@@ -112,6 +112,36 @@ end
 
 The `length` parameter is ignored if you're using `style: :uuid`, because UUIDs already have a fixed length. The `length` parameter also needs be an Integer, and can't be less than `4` or greater than `128`. If any of these constraints are broken, Identifiable will raise an error letting you know.
 
+## Configuration
+
+By default, Identifiable overrides Rails' `to_key` and `to_param` methods so that your URLs and DOM IDs will use your public IDs instead of your database IDs.
+
+This can break other gems that rely on the default behavior of Rails' `to_key` and `to_param` methods, like devise! You can configure Identifiable to not override these methods if you'd like:
+
+```ruby
+# In config/initializers/identifiable.rb
+Identifiable.configure do |config|
+  config.overwrite_to_key = false
+  config.overwrite_to_param = false
+end
+```
+
+The `overwrite_to_key` option controls whether Rails helpers like `dom_id` use your public ID or your database ID. The default value is `true`.
+
+The `overwrite_to_param` option controls whether URL helpers use your public ID or your database ID in routes. The default value is `true`.
+
+If you disable both options, your application will behave like this:
+
+```ruby
+@order = Order.last
+@order.id # => 14
+@order.public_id # => "87133275"
+orders_url(@order) # => https://example.app/orders/14
+
+# But you can still create URLs using the public ID
+orders_url(@order.public_id) # => https://example.app/orders/87133275
+```
+
 ## Alternatives
 
 I built Identifiable because I never could quite get the other gems that do similar things quite the way that I liked them. You might have the same experience with Identifiable, so if you try Identifiable and find that it's not quite to your tastes, try out some of these alternatives:

lib/identifiable.rb

@@ -3,9 +3,20 @@
 module Identifiable
   module Stylists
   end
+
+  class << self
+    def configuration
+      @configuration ||= Configuration.new
+    end
+
+    def configure
+      yield(configuration)
+    end
+  end
 end
 
 require "active_record"
+require "identifiable/configuration"
 require "identifiable/stylist"
 require "identifiable/stylists/alphanumeric"
 require "identifiable/stylists/numeric"

lib/identifiable/configuration.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module Identifiable
+  class Configuration
+    attr_accessor :overwrite_to_key, :overwrite_to_param
+
+    def initialize
+      @overwrite_to_key = true
+      @overwrite_to_param = true
+    end
+  end
+end

lib/identifiable/model.rb

@@ -125,13 +125,17 @@ def set_public_id!
     # such as `dom_id` will use the public ID instead of the regular ID when
     # identifying the record.
     def to_key
+      return super unless Identifiable.configuration.overwrite_to_key
+
       [self[self.class.identifiable_column]]
     end
 
     # By overriding ActiveRecord's `#to_param`, this means that Rails' helpers,
     # such as the `link_to` helpers will default to using the public ID
     # instead of the regular ID when identifying the record.
     def to_param
+      return super unless Identifiable.configuration.overwrite_to_param
+
       self[self.class.identifiable_column]
     end
   end

spec/configuration_spec.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+RSpec.describe Identifiable::Configuration do
+  let(:config) { described_class.new }
+
+  describe "#initialize" do
+    it "sets default values" do
+      expect(config.overwrite_to_key).to be_truthy
+      expect(config.overwrite_to_param).to be_truthy
+    end
+  end
+
+  describe "#overwrite_to_key" do
+    it "can be read" do
+      expect(config.overwrite_to_key).to be_truthy
+    end
+
+    it "can be set to false" do
+      config.overwrite_to_key = false
+      expect(config.overwrite_to_key).to be_falsey
+    end
+
+    it "can be set to true" do
+      config.overwrite_to_key = false
+      config.overwrite_to_key = true
+      expect(config.overwrite_to_key).to be_truthy
+    end
+  end
+
+  describe "#overwrite_to_param" do
+    it "can be read" do
+      expect(config.overwrite_to_param).to be_truthy
+    end
+
+    it "can be set to false" do
+      config.overwrite_to_param = false
+      expect(config.overwrite_to_param).to be_falsey
+    end
+
+    it "can be set to true" do
+      config.overwrite_to_param = false
+      config.overwrite_to_param = true
+      expect(config.overwrite_to_param).to be_truthy
+    end
+  end
+end

spec/identifiable_spec.rb

@@ -4,4 +4,84 @@
   it "has a version number" do
     expect(Identifiable::VERSION).not_to be nil
   end
+
+  describe ".configure" do
+    after do
+      # Reset configuration after each test
+      Identifiable.configure do |config|
+        config.overwrite_to_key = true
+        config.overwrite_to_param = true
+      end
+    end
+
+    it "yields a configuration object" do
+      expect { |b| Identifiable.configure(&b) }.to yield_with_args(Identifiable.configuration)
+    end
+
+    it "allows configuring overwrite_to_key" do
+      Identifiable.configure do |config|
+        config.overwrite_to_key = false
+      end
+
+      expect(Identifiable.configuration.overwrite_to_key).to be_falsey
+    end
+
+    it "allows configuring overwrite_to_param" do
+      Identifiable.configure do |config|
+        config.overwrite_to_param = false
+      end
+
+      expect(Identifiable.configuration.overwrite_to_param).to be_falsey
+    end
+
+    it "allows configuring multiple options at once" do
+      Identifiable.configure do |config|
+        config.overwrite_to_key = false
+        config.overwrite_to_param = false
+      end
+
+      expect(Identifiable.configuration.overwrite_to_key).to be_falsey
+      expect(Identifiable.configuration.overwrite_to_param).to be_falsey
+    end
+  end
+
+  describe ".configuration" do
+    after do
+      # Reset configuration after each test
+      Identifiable.configure do |config|
+        config.overwrite_to_key = true
+        config.overwrite_to_param = true
+      end
+    end
+
+    it "returns the same configuration object on multiple calls" do
+      config1 = Identifiable.configuration
+      config2 = Identifiable.configuration
+      expect(config1).to be(config2)
+    end
+
+    it "returns a configuration object that responds to configuration methods" do
+      config = Identifiable.configuration
+      expect(config).to respond_to(:overwrite_to_key)
+      expect(config).to respond_to(:overwrite_to_param)
+      expect(config).to respond_to(:overwrite_to_key=)
+      expect(config).to respond_to(:overwrite_to_param=)
+    end
+
+    it "maintains configuration changes across calls" do
+      Identifiable.configure do |config|
+        config.overwrite_to_key = false
+        config.overwrite_to_param = false
+      end
+
+      config = Identifiable.configuration
+      expect(config.overwrite_to_key).to be_falsey
+      expect(config.overwrite_to_param).to be_falsey
+
+      # Should persist
+      config_again = Identifiable.configuration
+      expect(config_again.overwrite_to_key).to be_falsey
+      expect(config_again.overwrite_to_param).to be_falsey
+    end
+  end
 end