add tests for regex

spec/unit/parser_spec.rb

@@ -26,4 +26,20 @@ describe GitHubChangelogGenerator::Parser do
       it { is_expected.to match_array([nil, nil]) }
     end
   end
+  describe "#self.user_project_from_option" do
+    # context "when option is invalid" do
+    #   it("should exit") { expect { GitHubChangelogGenerator::Parser.user_project_from_option("blah", nil) }.to raise_error(SystemExit) }
+    # end
+
+    context "when option is valid" do
+      subject { GitHubChangelogGenerator::Parser.user_project_from_option("skywinder/ActionSheetPicker-3.0", nil) }
+      it { is_expected.to be_a(Array) }
+      it { is_expected.to match_array(["skywinder", "ActionSheetPicker-3.0"]) }
+    end
+    context "when option nil" do
+      subject { GitHubChangelogGenerator::Parser.user_project_from_option(nil, nil) }
+      it { is_expected.to be_a(Array) }
+      it { is_expected.to match_array([nil, nil]) }
+    end
+  end
 end