feat: date like objects support (#198)

Tbh, I just went through appearances of `/(TimeLike|time_like)/` and
created similar logic for date like objects :D

I'm really hesitant about whether `DateTime` objects should be
considered `date_like` (although ActiveSupport defines
`DateTime#acts_like_date?`). Since `Date` and `DateTime` are never
equal, `expect(Date.new(2020, 1, 1)).to eq(DateTime.new(2020, 1, 1))`
will result in a confusing diff (see the
[spec/support/shared_examples/active_support.rb](https://github.com/mcmire/super_diff/pull/198/files#diff-4076c9b6c197bc5a4b90327f7efc27f9a0bc5f40ec98dfe94adf9c08f103a269R103-R143))

lib/super_diff.rb

@@ -1,6 +1,7 @@
 require "attr_extras/explicit"
 require "diff-lcs"
 require "patience_diff"
+require "date"
 
 module SuperDiff
   autoload(
@@ -57,6 +58,14 @@ def self.time_like?(value)
       value.is_a?(Time)
   end
 
+  def self.date_like?(value)
+    # Check for ActiveSupport's #acts_like_date? for their date-like objects
+    # In case class is both time-like and date-like, we should treat it as
+    # time-like. This is governed by the order of `Differs::DEFAULTS` entries
+    (value.respond_to?(:acts_like_date?) && value.acts_like_date?) ||
+      value.is_a?(Date)
+  end
+
   def self.primitive?(value)
     case value
     when true, false, nil, Symbol, Numeric, Regexp, Class

lib/super_diff/differs.rb

@@ -9,6 +9,7 @@ module Differs
     autoload :Main, "super_diff/differs/main"
     autoload :MultilineString, "super_diff/differs/multiline_string"
     autoload :TimeLike, "super_diff/differs/time_like"
+    autoload :DateLike, "super_diff/differs/date_like"
   end
 end
 

lib/super_diff/differs/date_like.rb

@@ -0,0 +1,15 @@
+module SuperDiff
+  module Differs
+    class DateLike < Base
+      def self.applies_to?(expected, actual)
+        SuperDiff.date_like?(expected) && SuperDiff.date_like?(actual)
+      end
+
+      protected
+
+      def operation_tree_builder_class
+        OperationTreeBuilders::DateLike
+      end
+    end
+  end
+end

lib/super_diff/differs/defaults.rb

@@ -4,6 +4,7 @@ module Differs
       Array,
       Hash,
       TimeLike,
+      DateLike,
       MultilineString,
       CustomObject,
       DefaultObject

lib/super_diff/object_inspection/inspection_tree_builders.rb

@@ -37,6 +37,10 @@ module InspectionTreeBuilders
         :TimeLike,
         "super_diff/object_inspection/inspection_tree_builders/time_like"
       )
+      autoload(
+        :DateLike,
+        "super_diff/object_inspection/inspection_tree_builders/date_like"
+      )
     end
   end
 end

lib/super_diff/object_inspection/inspection_tree_builders/date_like.rb

@@ -0,0 +1,41 @@
+module SuperDiff
+  module ObjectInspection
+    module InspectionTreeBuilders
+      class DateLike < Base
+        def self.applies_to?(value)
+          SuperDiff.date_like?(value)
+        end
+
+        def call
+          InspectionTree.new do
+            as_lines_when_rendering_to_lines(collection_bookend: :open) do
+              add_text { |date| "#<#{date.class} " }
+
+              when_rendering_to_lines { add_text "{" }
+            end
+
+            when_rendering_to_string do
+              add_text { |date| date.strftime("%Y-%m-%d") }
+            end
+
+            when_rendering_to_lines do
+              nested do |date|
+                insert_separated_list(%i[year month day]) do |name|
+                  add_text name.to_s
+                  add_text ": "
+                  add_inspection_of date.public_send(name)
+                end
+              end
+            end
+
+            as_lines_when_rendering_to_lines(collection_bookend: :close) do
+              when_rendering_to_lines { add_text "}" }
+
+              add_text ">"
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/super_diff/object_inspection/inspection_tree_builders/defaults.rb

@@ -7,6 +7,7 @@ module InspectionTreeBuilders
         Hash,
         Primitive,
         TimeLike,
+        DateLike,
         DefaultObject
       ].freeze
     end

lib/super_diff/operation_tree_builders.rb

@@ -12,6 +12,7 @@ module OperationTreeBuilders
       "super_diff/operation_tree_builders/multiline_string"
     )
     autoload :TimeLike, "super_diff/operation_tree_builders/time_like"
+    autoload :DateLike, "super_diff/operation_tree_builders/date_like"
   end
 end
 

lib/super_diff/operation_tree_builders/date_like.rb

@@ -0,0 +1,15 @@
+module SuperDiff
+  module OperationTreeBuilders
+    class DateLike < CustomObject
+      def self.applies_to?(expected, actual)
+        SuperDiff.date_like?(expected) && SuperDiff.date_like?(actual)
+      end
+
+      protected
+
+      def attribute_names
+        %w[year month day]
+      end
+    end
+  end
+end

lib/super_diff/operation_tree_builders/defaults.rb

@@ -1,5 +1,5 @@
 module SuperDiff
   module OperationTreeBuilders
-    DEFAULTS = [Array, Hash, TimeLike, CustomObject].freeze
+    DEFAULTS = [Array, Hash, TimeLike, DateLike, CustomObject].freeze
   end
 end

spec/integration/rspec/eq_matcher_spec.rb

@@ -252,6 +252,78 @@
     end
   end
 
+  context "when comparing two different Date instances" do
+    it "produces the correct failure message when used in the positive" do
+      as_both_colored_and_uncolored do |color_enabled|
+        snippet = <<~RUBY
+          expected = Date.new(2023, 10, 14)
+          actual = Date.new(2023, 10, 31)
+          expect(expected).to eq(actual)
+        RUBY
+        program = make_plain_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 "#<Date 2023-10-14>"
+                  plain " to eq "
+                  expected "#<Date 2023-10-31>"
+                  plain "."
+                end
+              end,
+            diff:
+              proc do
+                plain_line "  #<Date {"
+                plain_line "    year: 2023,"
+                plain_line "    month: 10,"
+                expected_line "-   day: 31"
+                actual_line "+   day: 14"
+                plain_line "  }>"
+              end
+          )
+
+        expect(program).to produce_output_when_run(expected_output).in_color(
+          color_enabled
+        )
+      end
+    end
+
+    it "produces the correct failure message when used in the negative" do
+      as_both_colored_and_uncolored do |color_enabled|
+        snippet = <<~RUBY
+          date = Date.new(2023, 10, 14)
+          expect(date).not_to eq(date)
+        RUBY
+        program = make_plain_test_program(snippet, color_enabled: color_enabled)
+
+        expected_output =
+          build_expected_output(
+            color_enabled: color_enabled,
+            snippet: "expect(date).not_to eq(date)",
+            expectation:
+              proc do
+                line do
+                  plain "Expected "
+                  actual "#<Date 2023-10-14>"
+                  plain " not to eq "
+                  expected "#<Date 2023-10-14>"
+                  plain "."
+                end
+              end
+          )
+
+        expect(program).to produce_output_when_run(expected_output).in_color(
+          color_enabled
+        )
+      end
+    end
+  end
+
   context "when comparing a single-line string with a multi-line string" do
     it "produces the correct failure message" do
       as_both_colored_and_uncolored do |color_enabled|

spec/support/shared_examples/active_support.rb

@@ -106,4 +106,83 @@
       end
     end
   end
+
+  context "when comparing Date instance and date-like DateTime instance for same day",
+          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 = Date.new(2023, 10, 14)
+          actual = DateTime.new(2023, 10, 14, 18, 22, 26)
+          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 "#<Date 2023-10-14>"
+                  plain " to eq "
+                  expected "#<DateTime 2023-10-14 18:22:26 +00:00 (+00:00)>"
+                  plain "."
+                end
+              end
+          )
+
+        expect(program).to produce_output_when_run(expected_output).in_color(
+          color_enabled
+        )
+      end
+    end
+  end
+
+  context "when comparing Date instance and date-like DateTime instance for another day",
+          active_record: true do
+    it "produces the diff for date like objects comparison" do
+      as_both_colored_and_uncolored do |color_enabled|
+        snippet = <<~RUBY
+          expected = Date.new(2023, 10, 14)
+          actual = DateTime.new(2023, 10, 31, 18, 22, 26)
+          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 "#<Date 2023-10-14>"
+                  plain " to eq "
+                  expected "#<DateTime 2023-10-31 18:22:26 +00:00 (+00:00)>"
+                  plain "."
+                end
+              end,
+            diff:
+              proc do
+                plain_line "  #<Date {"
+                plain_line "    year: 2023,"
+                plain_line "    month: 10,"
+                expected_line "-   day: 31"
+                actual_line "+   day: 14"
+                plain_line "  }>"
+              end
+          )
+
+        expect(program).to produce_output_when_run(expected_output).in_color(
+          color_enabled
+        )
+      end
+    end
+  end
 end