Add have_size matcher

spec/matchers/size_matcher_spec.cr

@@ -0,0 +1,121 @@
+require "../spec_helper"
+
+describe Spectator::Matchers::SizeMatcher do
+  describe "#match" do
+    context "returned MatchData" do
+      describe "#matched?" do
+        context "with a matching number of items" do
+          it "is true" do
+            array = %i[a b c]
+            size = array.size
+            partial = new_partial(array)
+            matcher = Spectator::Matchers::SizeMatcher.new(size)
+            match_data = matcher.match(partial)
+            match_data.matched?.should be_true
+          end
+        end
+
+        context "with a different number of items" do
+          it "is false" do
+            array = %i[a b c]
+            size = array.size + 1
+            partial = new_partial(array)
+            matcher = Spectator::Matchers::SizeMatcher.new(size)
+            match_data = matcher.match(partial)
+            match_data.matched?.should be_false
+          end
+        end
+      end
+
+      describe "#values" do
+        context "expected" do
+          it "is the size given" do
+            array = %i[a b c]
+            size = array.size + 1
+            partial = new_partial(array)
+            matcher = Spectator::Matchers::SizeMatcher.new(size)
+            match_data = matcher.match(partial)
+            match_data_value_sans_prefix(match_data.values, :expected)[:value].should eq(size)
+          end
+        end
+
+        context "actual" do
+          it "is the size of the set" do
+            array = %i[a b c]
+            size = array.size + 1
+            partial = new_partial(array)
+            matcher = Spectator::Matchers::SizeMatcher.new(size)
+            match_data = matcher.match(partial)
+            match_data_value_with_key(match_data.values, :actual).value.should eq(array.size)
+          end
+        end
+      end
+
+      describe "#message" do
+        it "contains the actual label" do
+          array = %i[a b c]
+          size = array.size + 1
+          label = "foobar"
+          partial = new_partial(array, label)
+          matcher = Spectator::Matchers::SizeMatcher.new(size)
+          match_data = matcher.match(partial)
+          match_data.message.should contain(label)
+        end
+
+        it "contains the expected label" do
+          array = %i[a b c]
+          size = array.size + 1
+          label = "foobar"
+          partial = new_partial(array)
+          matcher = Spectator::Matchers::SizeMatcher.new(size, label)
+          match_data = matcher.match(partial)
+          match_data.message.should contain(label)
+        end
+
+        context "when expected label is omitted" do
+          it "contains stringified form of expected value" do
+            array = %i[a b c]
+            size = array.size + 1
+            partial = new_partial(array)
+            matcher = Spectator::Matchers::SizeMatcher.new(size)
+            match_data = matcher.match(partial)
+            match_data.message.should contain(size.to_s)
+          end
+        end
+      end
+
+      describe "#negated_message" do
+        it "contains the actual label" do
+          array = %i[a b c]
+          size = array.size + 1
+          label = "foobar"
+          partial = new_partial(array, label)
+          matcher = Spectator::Matchers::SizeMatcher.new(size)
+          match_data = matcher.match(partial)
+          match_data.negated_message.should contain(label)
+        end
+
+        it "contains the expected label" do
+          array = %i[a b c]
+          size = array.size + 1
+          label = "foobar"
+          partial = new_partial(array)
+          matcher = Spectator::Matchers::SizeMatcher.new(size, label)
+          match_data = matcher.match(partial)
+          match_data.negated_message.should contain(label)
+        end
+
+        context "when expected label is omitted" do
+          it "contains stringified form of expected value" do
+            array = %i[a b c]
+            size = array.size + 1
+            partial = new_partial(array)
+            matcher = Spectator::Matchers::SizeMatcher.new(size)
+            match_data = matcher.match(partial)
+            match_data.negated_message.should contain(size.to_s)
+          end
+        end
+      end
+    end
+  end
+end