Fix === for multiple mocks of the same model

When the same model is mocked more than once in the same context,
comparing with the model class using `#===` would only return true for
the first of the mocks. All following mocks would return false when
compared to the original model class using `#===`.

For `#===` to work correctly, we register each mock in a "mock_store"
on the `RSpec::ActiveModel::Mocks::Mocks` module. The store is
implemented as an RSpec stub, so it is reset after each spec example.

Fixes #60

Author: bquorning

CHANGELOG.md

@@ -1,6 +1,10 @@
 ### Development
 [Full Changelog](https://github.com/rspec/rspec-activemodel-mocks/compare/v1.2.0...main)
 
+Bug fixes:
+
+* Fix `===` to work with multiple mocks. (@bquorning, #61)
+
 ### 1.2.0 / 2023-12-10
 [Full Changelog](https://github.com/rspec/rspec-activemodel-mocks/compare/v1.1.0...v1.2.0)
 

lib/rspec/active_model/mocks/mocks.rb

@@ -135,11 +135,16 @@ def self.param_delimiter; "-"; end
                 :blank? => false }.merge(stubs)
 
       double("#{model_class.name}_#{stubs[:id]}", stubs).tap do |m|
+        mock_store_klass = RSpec::ActiveModel::Mocks::Mocks
         if model_class.method(:===).owner == Module && !stubs.key?(:===)
+          allow(mock_store_klass).to receive(:mock_store) do
+            @mock_store ||= Hash.new { |h, k| h[k] = [] }
+          end
           allow(model_class).to receive(:===).and_wrap_original do |original, other|
-            m === other || original.call(other)
+            mock_store_klass.mock_store[model_class].any? { |ms| ms === other } || original.call(other)
           end
         end
+        mock_store_klass.mock_store[model_class] << m if mock_store_klass.respond_to?(:mock_store)
         msingleton = class << m; self; end
         msingleton.class_eval do
           include ActiveModelInstanceMethods

spec/rspec/active_model/mocks/mock_model_spec.rb

@@ -209,6 +209,19 @@ def self.===(_other)
       end
       # rubocop:enable Lint/LiteralAsCondition
     end
+
+    it "works for multiple mocks of the same model" do
+      foo = mock_model(MockableModel)
+      bar = mock_model(MockableModel)
+      baz = mock_model(MockableModelNoPrimaryKey)
+      quz = mock_model(MockableModel)
+
+      expect(MockableModel === foo).to be(true)
+      expect(MockableModel === bar).to be(true)
+      expect(MockableModel === baz).to be(false)
+      expect(MockableModelNoPrimaryKey === baz).to be(true)
+      expect(MockableModel === quz).to be(true)
+    end
   end
 
   describe "#kind_of?" do

spec/rspec/active_model/mocks/stub_model_spec.rb

@@ -181,5 +181,18 @@ def model_class
       end
       # rubocop:enable Lint/LiteralAsCondition
     end
+
+    it "works for multiple mocks of the same model" do
+      foo = stub_model(MockableModel)
+      bar = stub_model(MockableModel)
+      baz = stub_model(MockableModelNoPrimaryKey)
+      qux = stub_model(MockableModel)
+
+      expect(MockableModel === foo).to be(true)
+      expect(MockableModel === bar).to be(true)
+      expect(MockableModel === baz).to be(false)
+      expect(MockableModelNoPrimaryKey === baz).to be(true)
+      expect(MockableModel === qux).to be(true)
+    end
   end
 end