Refactoring: introduce local, return early

- use #reject
  - add basic spec around it

lib/github_changelog_generator/generator/generator_processor.rb

@@ -4,13 +4,12 @@ module GitHubChangelogGenerator
     # @param [Array] issues
     # @return [Array] filtered array
     def exclude_issues_by_labels(issues)
-      unless @options[:exclude_labels].nil?
-        issues = issues.select do |issue|
-          var = issue.labels.map(&:name) & @options[:exclude_labels]
-          !var.any?
-        end
+      return issues if !@options[:exclude_labels] || @options[:exclude_labels].empty?
+
+      issues.reject do |issue|
+        labels = issue.labels.map(&:name)
+        (labels & @options[:exclude_labels]).any?
       end
-      issues
     end
 
     # @return [Array] filtered issues accourding milestone

spec/unit/generator/generator_processor_spec.rb

@@ -0,0 +1,16 @@
+module GitHubChangelogGenerator
+  describe Generator do
+    context "#exclude_issues_by_labels" do
+      let(:label) {  double("the-bad-label", name: "BAD") }
+      let(:issue) { double("the-issue-to-be-excluded", labels: [label]) }
+      let(:issues) { [issue] }
+      subject(:generator) { described_class.new(exclude_labels: %w(BAD BOO))}
+
+      it "removes issues with labels in the exclude_label list" do
+        result = generator.exclude_issues_by_labels(issues)
+
+        expect(result).to be_empty
+      end
+    end
+  end
+end