Add RangeObject differ and OperationTreeBuilder

Author: lucaseras

lib/super_diff/basic.rb

@@ -14,6 +14,7 @@ module Basic
         Differs::Hash,
         Differs::TimeLike,
         Differs::DateLike,
+        Differs::RangeObject,
         Differs::MultilineString,
         Differs::CustomObject,
         Differs::DefaultObject
@@ -37,6 +38,7 @@ module Basic
         OperationTreeBuilders::TimeLike,
         OperationTreeBuilders::DateLike,
         OperationTreeBuilders::CustomObject,
+        OperationTreeBuilders::RangeObject,
         OperationTreeBuilders::DataObject
       )
 

lib/super_diff/basic/differs.rb

@@ -4,6 +4,7 @@ module Differs
       autoload :Array, "super_diff/basic/differs/array"
       autoload :CustomObject, "super_diff/basic/differs/custom_object"
       autoload :DateLike, "super_diff/basic/differs/date_like"
+      autoload :RangeObject, "super_diff/basic/differs/range_object"
       autoload :DefaultObject, "super_diff/basic/differs/default_object"
       autoload :Hash, "super_diff/basic/differs/hash"
       autoload :MultilineString, "super_diff/basic/differs/multiline_string"

lib/super_diff/basic/differs/range_object.rb

@@ -0,0 +1,17 @@
+module SuperDiff
+  module Basic
+    module Differs
+      class RangeObject < Core::AbstractDiffer
+        def self.applies_to?(expected, actual)
+          expected.is_a?(Range) && actual.is_a?(Range)
+        end
+
+        protected
+
+        def operation_tree_builder_class
+          OperationTreeBuilders::RangeObject
+        end
+      end
+    end
+  end
+end

lib/super_diff/basic/operation_tree_builders.rb

@@ -22,6 +22,8 @@ module OperationTreeBuilders
       )
       autoload :TimeLike, "super_diff/basic/operation_tree_builders/time_like"
       autoload :DateLike, "super_diff/basic/operation_tree_builders/date_like"
+      autoload :RangeObject,
+               "super_diff/basic/operation_tree_builders/range_object"
 
       class Main
         def self.call(*args)

lib/super_diff/basic/operation_tree_builders/range_object.rb

@@ -0,0 +1,36 @@
+module SuperDiff
+  module Basic
+    module OperationTreeBuilders
+      class RangeObject < SuperDiff::Core::AbstractOperationTreeBuilder
+        def self.applies_to?(expected, actual)
+          expected.is_a?(Range) && actual.is_a?(Range)
+        end
+
+        protected
+
+        def unary_operations
+          [
+            Core::UnaryOperation.new(
+              name: :delete,
+              collection: expected.to_s,
+              key: 0,
+              index: 0,
+              value: expected.to_s
+            ),
+            Core::UnaryOperation.new(
+              name: :insert,
+              collection: actual.to_s,
+              key: 0,
+              index: 0,
+              value: actual.to_s
+            )
+          ]
+        end
+
+        def build_operation_tree
+          OperationTrees::MultilineString.new([])
+        end
+      end
+    end
+  end
+end

spec/integration/rspec/eq_matcher_spec.rb

@@ -1056,6 +1056,41 @@
     end
   end
 
+  context "when comparing ranges" do
+    it "produces the correct failure message when used in the positive" do
+      as_both_colored_and_uncolored do |color_enabled|
+        snippet = "expect(1..5).to eq(5..6)"
+        program = make_plain_test_program(snippet, color_enabled: color_enabled)
+
+        expected_output =
+          build_expected_output(
+            color_enabled: color_enabled,
+            snippet: snippet,
+            newline_before_expectation: true,
+            expectation:
+              proc do
+                line do
+                  plain "Expected "
+                  actual "1..5"
+                  plain " to eq "
+                  expected "5..6"
+                  plain "."
+                end
+              end,
+            diff:
+              proc do
+                expected_line "- 5..6"
+                actual_line "+ 1..5"
+              end
+          )
+
+        expect(program).to produce_output_when_run(expected_output).in_color(
+          color_enabled
+        )
+      end
+    end
+  end
+
   it_behaves_like "a matcher that supports elided diffs" do
     let(:matcher) { :eq }
   end

spec/unit/basic/operation_tree_builders/range_object_spec.rb

@@ -0,0 +1,25 @@
+require "spec_helper"
+
+RSpec.describe SuperDiff, type: :unit do
+  describe ".diff" do
+    subject(:diff) { described_class.diff(a, b) }
+
+    context "when given two Range objects" do
+      let(:a) { 1..5 }
+      let(:b) { 5..6 }
+
+      it "diffs their member attributes" do
+        expected_output =
+          SuperDiff::Core::Helpers
+            .style(color_enabled: true) do
+              expected_line "- 1..5"
+              actual_line "+ 5..6"
+            end
+            .to_s
+            .chomp
+
+        expect(diff).to eq(expected_output)
+      end
+    end
+  end
+end