Fix diffing of ActiveRecord objects in nested objects

When displaying a diff of two ActiveRecord objects that exist within an
array or hash or something like that, make sure that we are using the
CustomObject diff formatter instead of the DefaultObject diff formatter.
When inspecting attributes, this will output something like:

    foo: "bar",
    baz: "qux"

instead of:

    @foo="bar",
    @baz="qux"

Author: mcmire

lib/super_diff/active_record.rb

@@ -36,6 +36,8 @@ module ActiveRecord
   end
 end
 
+require "super_diff/active_record/monkey_patches"
+
 SuperDiff::ObjectInspection.map.prepend(
   SuperDiff::ActiveRecord::ObjectInspection::MapExtension,
 )

lib/super_diff/active_record/monkey_patches.rb

@@ -0,0 +1,9 @@
+# rubocop:disable Style/BracesAroundHashParameters, Style/ClassAndModuleChildren
+class ActiveRecord::Base
+  def attributes_for_super_diff
+    (attributes.keys.sort - ["id"]).reduce({ id: id }) do |hash, key|
+      hash.merge(key.to_sym => attributes[key])
+    end
+  end
+end
+# rubocop:enable Style/BracesAroundHashParameters, Style/ClassAndModuleChildren

lib/super_diff/operation_sequences/base.rb

@@ -6,6 +6,20 @@ def to_diff(indent_level:, add_comma: false, collection_prefix: nil)
         raise NotImplementedError
       end
       # rubocop:enable Lint/UnusedMethodArgument
+
+      def pretty_print(pp)
+        pp.text "#{self.class.name}.new(["
+        pp.group_sub do
+          pp.nest(2) do
+            pp.breakable
+            pp.seplist(self) do |value|
+              pp.pp value
+            end
+          end
+        end
+        pp.breakable
+        pp.text("])")
+      end
     end
   end
 end

lib/super_diff/rspec/operational_sequencers/object_having_attributes.rb

@@ -9,7 +9,6 @@ def self.applies_to?(expected, _actual)
         protected
 
         def build_operation_sequencer
-          # TODO: Test this
           if actual.respond_to?(:attributes_for_super_diff)
             OperationSequences::CustomObject.new([], value_class: actual.class)
           else
@@ -18,7 +17,6 @@ def build_operation_sequencer
         end
 
         def attribute_names
-          # TODO: Test this
           if actual.respond_to?(:attributes_for_super_diff)
             actual.attributes_for_super_diff.keys | expected.expected.keys
           else

spec/support/models/active_record/query.rb

@@ -0,0 +1,15 @@
+module SuperDiff
+  module Test
+    module Models
+      module ActiveRecord
+        class Query
+          attr_reader :results
+
+          def initialize(results:)
+            @results = results
+          end
+        end
+      end
+    end
+  end
+end

spec/support/shared_examples/active_record.rb

@@ -335,4 +335,75 @@
       end
     end
   end
+
+  describe "and RSpec's #match matcher" do
+    context "when the expected value includes an ActiveRecord object" do
+      it "produces the correct output" do
+        as_both_colored_and_uncolored do |color_enabled|
+          snippet = <<~TEST.strip
+            SuperDiff::Test::Models::ActiveRecord::Person.create!(
+              name: "Murphy",
+              age: 20
+            )
+
+            expected = [
+              an_object_having_attributes(
+                results: [
+                  an_object_having_attributes(name: "John", age: 19)
+                ]
+              )
+            ]
+
+            actual = [
+              SuperDiff::Test::Models::ActiveRecord::Query.new(
+                results: SuperDiff::Test::Models::ActiveRecord::Person.all
+              )
+            ]
+
+            expect(actual).to match(expected)
+          TEST
+
+          program = make_program(snippet, color_enabled: color_enabled)
+
+          expected_output = build_expected_output(
+            color_enabled: color_enabled,
+            snippet: %|expect(actual).to match(expected)|,
+            newline_before_expectation: true,
+            expectation: proc {
+              line do
+                plain "Expected "
+                beta %|[#<SuperDiff::Test::Models::ActiveRecord::Query @results=#<ActiveRecord::Relation [#<SuperDiff::Test::Models::ActiveRecord::Person id: 1, name: "Murphy", age: 20>]>>]|
+              end
+
+              line do
+                plain "to match "
+                alpha %|[#<an object having attributes (results: [#<an object having attributes (name: "John", age: 19)>])>]|
+              end
+            },
+            diff: proc {
+              plain_line %|  [|
+              plain_line %|    #<SuperDiff::Test::Models::ActiveRecord::Query {|
+              plain_line %|      @results=#<ActiveRecord::Relation [|
+              plain_line %|        #<SuperDiff::Test::Models::ActiveRecord::Person {|
+              plain_line %|          id: 1,|
+              # alpha_line %|-         age: 19,|  # TODO
+              alpha_line %|-         age: 19|
+              beta_line  %|+         age: 20,|
+              alpha_line %|-         name: "John"|
+              beta_line  %|+         name: "Murphy"|
+              plain_line %|        }>|
+              plain_line %|      ]>|
+              plain_line %|    }>|
+              plain_line %|  ]|
+            },
+          )
+
+          expect(program).
+            to produce_output_when_run(expected_output).
+            in_color(color_enabled).
+            removing_object_ids
+        end
+      end
+    end
+  end
 end