feat: Add without_instance_methods qualifier to enum matcher (#1636)

* feat: Add without_instance_methods qualifier to enum matcher

* Fix type and name collision

lib/shoulda/matchers/active_record/define_enum_for_matcher.rb

@@ -253,8 +253,29 @@ module ActiveRecord
       #         validating(allowing_nil: true)
       #     end
       #
-      # @return [DefineEnumForMatcher]
+      # ##### without_instance_methods
+      #
+      # Use `without_instance_methods` to exclude the check for instance methods.
+      #
+      #     class Issue < ActiveRecord::Base
+      #       enum status: [:open, :closed], instance_methods: false
+      #     end
+      #
+      #     # RSpec
+      #     RSpec.describe Issue, type: :model do
+      #       it do
+      #         should define_enum_for(:status).
+      #           without_instance_methods
+      #       end
+      #     end
       #
+      #     # Minitest (Shoulda)
+      #     class ProcessTest < ActiveSupport::TestCase
+      #       should define_enum_for(:status).
+      #         without_instance_methods
+      #     end
+      #
+      # @return [DefineEnumForMatcher]
       def define_enum_for(attribute_name)
         DefineEnumForMatcher.new(attribute_name)
       end
@@ -263,7 +284,7 @@ def define_enum_for(attribute_name)
       class DefineEnumForMatcher
         def initialize(attribute_name)
           @attribute_name = attribute_name
-          @options = { expected_enum_values: [], scopes: true }
+          @options = { expected_enum_values: [], scopes: true, instance_methods: true }
         end
 
         def description
@@ -319,6 +340,11 @@ def without_scopes
           self
         end
 
+        def without_instance_methods
+          options[:instance_methods] = false
+          self
+        end
+
         def with_default(default_value)
           options[:default] = default_value
           self
@@ -531,16 +557,24 @@ def model
         end
 
         def enum_value_methods_exist?
-          if instance_methods_exist?
-            true
-          else
+          if options[:instance_methods]
+            return true if instance_methods_exist?
+
             message = missing_methods_message
+            message << " (we can't tell which)" if [expected_prefix, expected_suffix].any?
 
-            message << " (we can't tell which)"
+            @failure_message_continuation = message
+
+            false
+          elsif instance_methods_exist?
+            message = "#{attribute_name.inspect} does map to these values"
+            message << ' with instance methods, but expected no instance methods'
 
             @failure_message_continuation = message
 
             false
+          else
+            true
           end
         end
 
@@ -589,6 +623,8 @@ def missing_methods_message
           elsif expected_suffix
             message << 'configured with either a different suffix or no '
             message << 'suffix at all'
+          elsif expected_instance_methods?
+            message << 'configured with no instance methods'
           else
             ''
           end
@@ -664,6 +700,10 @@ def expected_instance_methods
           end
         end
 
+        def expected_instance_methods?
+          options[:instance_methods]
+        end
+
         def expected_prefix
           if options.include?(:prefix)
             if options[:prefix] == true

spec/unit/shoulda/matchers/active_record/define_enum_for_matcher_spec.rb

@@ -1114,6 +1114,77 @@ def self.statuses
         end
       end
     end
+
+    describe 'qualified with #without_instance_methods' do
+      context 'if instance methods are set to false on the enum but without_instance_methods is not used' do
+        it 'rejects with failure message' do
+          record = build_record_with_array_values(
+            attribute_name: :attr,
+            instance_methods: false,
+          )
+
+          matcher = lambda do
+            expect(record).
+              to define_enum_for(:attr).
+              with_values(['published', 'unpublished', 'draft'])
+          end
+
+          message = format_message(<<-MESSAGE)
+          Expected Example to define :attr as an enum backed by an integer,
+          mapping ‹"published"› to ‹0›, ‹"unpublished"› to ‹1›, and ‹"draft"› to
+          ‹2›. :attr does map to these values, but the enum is configured with no
+          instance methods.
+          MESSAGE
+
+          expect(&matcher).to fail_with_message(message)
+        end
+      end
+
+      context 'if instance methods are set to false on the enum' do
+        it 'matches' do
+          record = build_record_with_array_values(
+            attribute_name: :attr,
+            instance_methods: false,
+          )
+
+          matcher = lambda do
+            define_enum_for(:attr).
+              with_values(['published', 'unpublished', 'draft']).
+              without_instance_methods
+          end
+
+          expect(&matcher).
+            to match_against(record).
+            or_fail_with(<<-MESSAGE)
+            Expected Example not to define :attr as an enum backed by an integer,
+            mapping ‹"published"› to ‹0›, ‹"unpublished"› to ‹1›, and ‹"draft"› to
+            ‹2›, but it did.
+          MESSAGE
+        end
+      end
+
+      context 'if instance methods are not set to false on the enum' do
+        it 'rejects with failure message' do
+          record = build_record_with_array_values(attribute_name: :attr)
+
+          matcher = lambda do
+            expect(record).
+              to define_enum_for(:attr).
+              with_values(['published', 'unpublished', 'draft']).
+              without_instance_methods
+          end
+
+          message = format_message(<<-MESSAGE)
+          Expected Example to define :attr as an enum backed by an integer,
+          mapping ‹"published"› to ‹0›, ‹"unpublished"› to ‹1›, and ‹"draft"› to
+          ‹2›. :attr does map to these values with instance methods, but expected
+          no instance methods.
+          MESSAGE
+
+          expect(&matcher).to fail_with_message(message)
+        end
+      end
+    end
   end
 
   if rails_version =~ '~> 6.0'
@@ -1198,7 +1269,8 @@ def build_record_with_array_values(
     attribute_alias: nil,
     scopes: true,
     default: nil,
-    validate: false
+    validate: false,
+    instance_methods: true
   )
     build_record_with_enum_attribute(
       model_name: model_name,
@@ -1211,6 +1283,7 @@ def build_record_with_array_values(
       scopes: scopes,
       default: default,
       validate: validate,
+      instance_methods: instance_methods,
     )
   end
 
@@ -1244,7 +1317,8 @@ def build_record_with_enum_attribute(
     prefix: false,
     suffix: false,
     default: nil,
-    validate: false
+    validate: false,
+    instance_methods: true
   )
     enum_name = attribute_alias || attribute_name
     model = define_model(
@@ -1262,7 +1336,7 @@ def build_record_with_enum_attribute(
     }
 
     if rails_version >= 7.0
-      model.enum(enum_name, values, prefix: prefix, suffix: suffix, validate: validate, default: default)
+      model.enum(enum_name, values, prefix: prefix, suffix: suffix, validate: validate, default: default, instance_methods: instance_methods)
     else
       params.merge!(_scopes: scopes)
       model.enum(params)