Update EmptyMatcher to use MatchData

spec/matchers/empty_matcher_spec.cr

@@ -1,43 +1,73 @@
 require "../spec_helper"
 
 describe Spectator::Matchers::EmptyMatcher do
-  describe "#match?" do
-    context "with an empty set" do
-      it "is true" do
-        array = [] of Symbol
-        partial = new_partial(array)
-        matcher = Spectator::Matchers::EmptyMatcher.new
-        matcher.match?(partial).should be_true
+  describe "#match" do
+    context "returned MatchData" do
+      describe "#matched?" do
+        context "with an empty set" do
+          it "is true" do
+            array = [] of Symbol
+            partial = new_partial(array)
+            matcher = Spectator::Matchers::EmptyMatcher.new
+            match_data = matcher.match(partial)
+            match_data.matched?.should be_true
+          end
+        end
+
+        context "with a filled set" do
+          it "is false" do
+            array = %i[a b c]
+            partial = new_partial(array)
+            matcher = Spectator::Matchers::EmptyMatcher.new
+            match_data = matcher.match(partial)
+            match_data.matched?.should be_false
+          end
+        end
       end
-    end
 
-    context "with a filled set" do
-      it "is false" do
-        array = %i[a b c]
-        partial = new_partial(array)
-        matcher = Spectator::Matchers::EmptyMatcher.new
-        matcher.match?(partial).should be_false
+      describe "#values" do
+        context "expected" do
+          it "is an empty set" do
+            array = %i[a b c]
+            partial = new_partial(array)
+            matcher = Spectator::Matchers::EmptyMatcher.new
+            match_data = matcher.match(partial)
+            match_data.values[:expected].size.should eq(0)
+          end
+        end
+
+        context "actual" do
+          it "is the actual set" do
+            array = %i[a b c]
+            partial = new_partial(array)
+            matcher = Spectator::Matchers::EmptyMatcher.new
+            match_data = matcher.match(partial)
+            match_data.values[:actual].should eq(array)
+          end
+        end
       end
-    end
-  end
 
-  describe "#message" do
-    it "contains the actual label" do
-      array = %i[a b c]
-      label = "everything"
-      partial = new_partial(array, label)
-      matcher = Spectator::Matchers::EmptyMatcher.new
-      matcher.message(partial).should contain(label)
-    end
-  end
+      describe "#message" do
+        it "contains the actual label" do
+          array = %i[a b c]
+          label = "everything"
+          partial = new_partial(array, label)
+          matcher = Spectator::Matchers::EmptyMatcher.new
+          match_data = matcher.match(partial)
+          match_data.message.should contain(label)
+        end
+      end
 
-  describe "#negated_message" do
-    it "contains the actual label" do
-      array = %i[a b c]
-      label = "everything"
-      partial = new_partial(array, label)
-      matcher = Spectator::Matchers::EmptyMatcher.new
-      matcher.negated_message(partial).should contain(label)
+      describe "#negated_message" do
+        it "contains the actual label" do
+          array = %i[a b c]
+          label = "everything"
+          partial = new_partial(array, label)
+          matcher = Spectator::Matchers::EmptyMatcher.new
+          match_data = matcher.match(partial)
+          match_data.negated_message.should contain(label)
+        end
+      end
     end
   end
 end