Add inspection tree builder for ActiveSupport::OrderedOptions (#202)

I believe this fixes #199 and, I suspect, fixes #163. See
#199 (comment)
for more background. You can reproduce errors like those raised in the
aforementioned issues by checking out
26e1f6c and running `bundle exec rspec
spec/unit/active_support/object_inspection_spec.rb`.

The solution I opted for here was to create a hash-like inspector for
`ActiveSupport::OrderedOptions` that takes precedence over the default
`CustomObject` inspector, which in turn [takes precedence
over](https://github.com/mcmire/super_diff/blob/fb6718a2b60bc8135424295cc069a4b984983f77/lib/super_diff/object_inspection/inspection_tree_builders/defaults.rb#L5-L7)
the `Hash` inspector.

The `OrderedOptions` inspection tree is basically a copy-paste of the
one for `HashWithIndifferentAccess` – let me know if I should try to DRY
those up.

lib/super_diff/active_support.rb

@@ -18,7 +18,8 @@ module ActiveSupport
         OperationTreeBuilders::HashWithIndifferentAccess
       )
       config.add_extra_inspection_tree_builder_classes(
-        ObjectInspection::InspectionTreeBuilders::HashWithIndifferentAccess
+        ObjectInspection::InspectionTreeBuilders::HashWithIndifferentAccess,
+        ObjectInspection::InspectionTreeBuilders::OrderedOptions
       )
     end
   end

lib/super_diff/active_support/object_inspection/inspection_tree_builders.rb

@@ -6,6 +6,10 @@ module InspectionTreeBuilders
           :HashWithIndifferentAccess,
           "super_diff/active_support/object_inspection/inspection_tree_builders/hash_with_indifferent_access"
         )
+        autoload(
+          :OrderedOptions,
+          "super_diff/active_support/object_inspection/inspection_tree_builders/ordered_options"
+        )
       end
     end
   end

lib/super_diff/active_support/object_inspection/inspection_tree_builders/ordered_options.rb

@@ -0,0 +1,33 @@
+module SuperDiff
+  module ActiveSupport
+    module ObjectInspection
+      module InspectionTreeBuilders
+        class OrderedOptions < SuperDiff::ObjectInspection::InspectionTreeBuilders::Hash
+          def self.applies_to?(value)
+            value.is_a?(::ActiveSupport::OrderedOptions)
+          end
+
+          def call
+            SuperDiff::ObjectInspection::InspectionTree.new do
+              as_lines_when_rendering_to_lines(collection_bookend: :open) do
+                add_text "#<OrderedOptions {"
+              end
+
+              when_rendering_to_string { add_text " " }
+
+              nested do |ordered_options|
+                insert_hash_inspection_of(ordered_options.to_hash)
+              end
+
+              when_rendering_to_string { add_text " " }
+
+              as_lines_when_rendering_to_lines(collection_bookend: :close) do
+                add_text "}>"
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end

spec/spec_helper.rb

@@ -65,6 +65,9 @@
   config.default_formatter = "documentation" if !%w[true 1].include?(ENV["CI"])
 
   config.filter_run_excluding active_record: true unless active_record_available
+  unless defined?(ActiveSupport)
+    config.filter_run_excluding active_support: true
+  end
 
   config.order = :random
   Kernel.srand config.seed

spec/support/shared_examples/active_support.rb

@@ -64,4 +64,46 @@
       end
     end
   end
+
+  context "when comparing OrderedOptions and Hash instances",
+          active_record: true do
+    it "produces the correct failure message when used in the positive" do
+      as_both_colored_and_uncolored do |color_enabled|
+        snippet = <<~RUBY
+          expected = {beep: :bip}
+          actual = ::ActiveSupport::OrderedOptions[beep: :boop]
+          expect(expected).to eq(actual)
+        RUBY
+        program =
+          make_rspec_rails_test_program(snippet, color_enabled: color_enabled)
+
+        expected_output =
+          build_expected_output(
+            color_enabled: color_enabled,
+            snippet: "expect(expected).to eq(actual)",
+            expectation:
+              proc do
+                line do
+                  plain "Expected "
+                  actual "{ beep: :bip }"
+                  plain " to eq "
+                  expected "#<OrderedOptions { beep: :boop }>"
+                  plain "."
+                end
+              end,
+            diff:
+              proc do
+                plain_line "  {"
+                expected_line "-   beep: :boop"
+                actual_line "+   beep: :bip"
+                plain_line "  }"
+              end
+          )
+
+        expect(program).to produce_output_when_run(expected_output).in_color(
+          color_enabled
+        )
+      end
+    end
+  end
 end

spec/unit/active_support/object_inspection_spec.rb

@@ -0,0 +1,62 @@
+require "spec_helper"
+
+RSpec.describe SuperDiff, type: :unit do
+  describe ".inspect_object",
+           "for ActiveSupport objects",
+           active_support: true do
+    context "given an ActiveSupport::OrderedOptions object" do
+      context "given as_lines: false" do
+        it "returns an inspected version of the object" do
+          string =
+            described_class.inspect_object(
+              ::ActiveSupport::OrderedOptions[name: "Bob", age: 42],
+              as_lines: false
+            )
+          expect(string).to eq(%(#<OrderedOptions { name: "Bob", age: 42 }>))
+        end
+      end
+
+      context "given as_lines: true" do
+        it "returns an inspected version of the object as multiple Lines" do
+          tiered_lines =
+            described_class.inspect_object(
+              ::ActiveSupport::OrderedOptions[name: "Bob", age: 42],
+              as_lines: true,
+              type: :delete,
+              indentation_level: 1
+            )
+          expect(tiered_lines).to match(
+            [
+              an_object_having_attributes(
+                type: :delete,
+                indentation_level: 1,
+                value: "#<OrderedOptions {",
+                collection_bookend: :open
+              ),
+              an_object_having_attributes(
+                type: :delete,
+                indentation_level: 2,
+                prefix: "name: ",
+                value: "\"Bob\"",
+                add_comma: true
+              ),
+              an_object_having_attributes(
+                type: :delete,
+                indentation_level: 2,
+                prefix: "age: ",
+                value: "42",
+                add_comma: false
+              ),
+              an_object_having_attributes(
+                type: :delete,
+                indentation_level: 1,
+                value: "}>",
+                collection_bookend: :close
+              )
+            ]
+          )
+        end
+      end
+    end
+  end
+end