Add ability to ignore a label.

assets/lib/filters/label.rb

@@ -8,15 +8,21 @@ def initialize(pull_requests:, input: Input.instance)
     end
 
     def pull_requests
+      if @input.source.no_label
+        @pull_requests = @pull_requests.reject do |pr|
+          issue = Octokit.issue(@input.source.repo, pr.id)
+          labels = issue[:labels] || []
+          labels.find { |l| l['name'].to_s.casecmp(@input.source.no_label.to_s.downcase).zero? }
+        end
+      end
       if @input.source.label
-        @memoized ||= @pull_requests.select do |pr|
+        @pull_requests = @pull_requests.select do |pr|
           issue  = Octokit.issue(@input.source.repo, pr.id)
           labels = issue[:labels] || []
           labels.find { |l| l['name'].to_s.casecmp(@input.source.label.to_s.downcase).zero? }
         end
-      else
-        @pull_requests
       end
+      @pull_requests
     end
   end
 end

spec/filters/label_spec.rb

@@ -42,5 +42,12 @@ def stub_json(uri, body)
 
       expect(filter.pull_requests).to eq [pr]
     end
+
+    it 'only returns PRs with that label' do
+      payload = { 'source' => { 'repo' => 'user/repo', 'no_label' => 'feature' } }
+      filter = described_class.new(pull_requests: pull_requests, input: Input.instance(payload: payload))
+
+      expect(filter.pull_requests).to eq [pr]
+    end
   end
 end