Resolved #214. Added tests for this case. small refacroting

spec/unit/generator/generator_tags_spec.rb

@@ -1,5 +1,5 @@
 describe GitHubChangelogGenerator::Generator do
-  describe "#get_filtered_tags" do
+  describe "#filter_between_tags" do
     context "when between_tags nil" do
       before do
         @generator = GitHubChangelogGenerator::Generator.new(between_tags: nil)
@@ -45,4 +45,25 @@ describe GitHubChangelogGenerator::Generator do
       it { is_expected.to match_array(%w(1)) }
     end
   end
+
+  describe "#get_filtered_tags" do
+    subject { generator.get_filtered_tags(%w(1 2 3 4 5)) }
+    # before { generator.get_filtered_tags(%w(1 2 3 4 5)) }
+
+    context "with excluded and between tags" do
+      let(:generator) { GitHubChangelogGenerator::Generator.new(between_tags: %w(1 2 3), exclude_tags: %w(2)) }
+      it { is_expected.to be_a Array }
+      it { is_expected.to match_array(%w(1 3)) }
+    end
+  end
+
+  describe "#filter_excluded_tags" do
+    subject { generator.filter_excluded_tags(%w(1 2 3)) }
+
+    context "with valid excluded tags" do
+      let(:generator) { GitHubChangelogGenerator::Generator.new(exclude_tags: %w(3)) }
+      it { is_expected.to be_a Array }
+      it { is_expected.to match_array(%w(1 2)) }
+    end
+  end
 end