Allow a checker to be retried in case it fails

.rubocop.yml

@@ -10,7 +10,8 @@ AllCops:
 #
 
 Layout/DotPosition:
-  EnforcedStyle: trailing
+  Enabled: false
+  StyleGuide: https://relaxed.ruby.style/#layoutdotposition
 
 Layout/FirstHashElementIndentation:
   EnforcedStyle: consistent

lib/checker_jobs/checks/base.rb

@@ -1,10 +1,10 @@
 CheckerJobs::Checks::Base = Struct.new(:klass, :name, :options, :block) do
-  def perform
+  def perform(iteration = 0)
     result = CheckerJobs.configuration.around_check.call do
       klass.new.instance_exec(&block)
     end
 
-    result.tap { |res| handle_result(res) }
+    result.tap { |res| handle_result(res, iteration) }
   end
 
   private
@@ -14,7 +14,19 @@ def notify(count:, entries: nil)
     notifier_class.new(self, count, entries).notify
   end
 
-  def handle_result(_result)
+  def handle_result(_result, _retry_count)
     raise NotImplementedError
   end
+
+  def handle_retry(count, iteration, entries = nil)
+    retry?(iteration) ? perform(iteration + 1) : notify(count: count, entries: entries)
+  end
+
+  def retry?(iteration)
+    iteration < max_retry
+  end
+
+  def max_retry
+    @_max_retry ||= options.fetch(:retry, 0).clamp(0, 3)
+  end
 end

lib/checker_jobs/checks/ensure_fewer.rb

@@ -1,10 +1,10 @@
 class CheckerJobs::Checks::EnsureFewer < CheckerJobs::Checks::Base
   private
 
-  def handle_result(result)
+  def handle_result(result, iteration)
     case result
     when Numeric
-      notify(count: result) if result > options.fetch(:than)
+      handle_retry(result, iteration) if result > options.fetch(:than)
     else
       raise ArgumentError, "Unsupported result: '#{result.class.name}' for 'ensure_less'"
     end

lib/checker_jobs/checks/ensure_more.rb

@@ -1,10 +1,10 @@
 class CheckerJobs::Checks::EnsureMore < CheckerJobs::Checks::Base
   private
 
-  def handle_result(result)
+  def handle_result(result, iteration)
     case result
     when Numeric
-      notify(count: result) if result < options.fetch(:than)
+      handle_retry(result, iteration) if result < options.fetch(:than)
     else
       raise ArgumentError, "Unsupported result: '#{result.class.name}' for 'ensure_more'"
     end

lib/checker_jobs/checks/ensure_no.rb

@@ -1,14 +1,14 @@
 class CheckerJobs::Checks::EnsureNo < CheckerJobs::Checks::Base
   private
 
-  def handle_result(result)
+  def handle_result(result, iteration)
     case result
     when Numeric
-      notify(count: result) unless result.zero?
+      handle_retry(result, iteration) unless result.zero?
     when Enumerable
-      notify(count: result.size, entries: result) unless result.empty?
+      handle_retry(result.size, iteration, result) unless result.empty?
     when TrueClass, FalseClass
-      notify(count: 1) if result
+      handle_retry(1, iteration) if result
     else
       raise ArgumentError, "Unsupported result: '#{result.class.name}' for 'ensure_no'"
     end

lib/checker_jobs/notifiers/email.rb

@@ -28,9 +28,9 @@ def valid?
   end
 
   def mailer_options
-    @_mailer_options ||= @defaults.
-                        merge(email_options).
-                        merge(@check.klass.notifier_options)
+    @_mailer_options ||= @defaults
+                         .merge(email_options)
+                         .merge(@check.klass.notifier_options)
   end
 
   def email_options

spec/checker_jobs/checks/base_spec.rb

@@ -39,7 +39,7 @@
       it "keeps handling the result outside the around_check delegation" do
         allow(instance).to receive(:handle_result).and_call_original
         perform
-        expect(instance).to have_received(:handle_result).with(0)
+        expect(instance).to have_received(:handle_result).with(0, 0)
       end
     end
   end

spec/checker_jobs/checks/ensure_fewer_spec.rb

@@ -1,14 +1,16 @@
 RSpec.describe CheckerJobs::Checks::EnsureFewer, :bugsnag, :configuration do
   include BugsnagHelpers
 
-  let(:instance) { described_class.new(checker_klass, "ensure_name", { than: 3 }, block) }
+  let(:instance) { described_class.new(checker_klass, "ensure_name", options, block) }
   let(:checker_klass) do
     Class.new do
       include CheckerJobs::Base
       notify :bugsnag
     end
   end
 
+  let(:options) { { than: 3 } }
+
   describe "#perform" do
     subject(:perform) { instance.perform }
 
@@ -29,5 +31,27 @@
 
       include_examples "sends_a_bugsnag_notification"
     end
+
+    context "when retry option is used" do
+      let(:options) { { than: 3, retry: 1 } }
+
+      context "when block's result is lower than the threshold" do
+        let(:block) { Proc.new { 2 } }
+
+        include_examples "does_not_send_a_bugsnag_notification"
+      end
+
+      context "when block's result is greater than the threshold" do
+        let(:block) { Proc.new { 4 } }
+
+        it "sends 2 sidekiq jobs" do
+          allow(instance).to receive(:perform).and_call_original
+          perform
+          expect(instance).to have_received(:perform).twice
+        end
+
+        include_examples "sends_a_bugsnag_notification"
+      end
+    end
   end
 end

spec/checker_jobs/checks/ensure_more_spec.rb

@@ -1,14 +1,16 @@
 RSpec.describe CheckerJobs::Checks::EnsureMore, :bugsnag, :configuration do
   include BugsnagHelpers
 
-  let(:instance) { described_class.new(checker_klass, "ensure_name", { than: 3 }, block) }
+  let(:instance) { described_class.new(checker_klass, "ensure_name", options, block) }
   let(:checker_klass) do
     Class.new do
       include CheckerJobs::Base
       notify :bugsnag
     end
   end
 
+  let(:options) { { than: 3 } }
+
   describe "#perform" do
     subject(:perform) { instance.perform }
 
@@ -29,5 +31,27 @@
 
       include_examples "does_not_send_a_bugsnag_notification"
     end
+
+    context "when retry option is used" do
+      let(:options) { { than: 3, retry: 1 } }
+
+      context "when block's result is greater than the threshold" do
+        let(:block) { Proc.new { 4 } }
+
+        include_examples "does_not_send_a_bugsnag_notification"
+      end
+
+      context "when block's result is lower than the threshold" do
+        let(:block) { Proc.new { 2 } }
+
+        it "sends 2 sidekiq jobs" do
+          allow(instance).to receive(:perform).and_call_original
+          perform
+          expect(instance).to have_received(:perform).twice
+        end
+
+        include_examples "sends_a_bugsnag_notification"
+      end
+    end
   end
 end

spec/checker_jobs/checks/ensure_no_spec.rb

@@ -1,13 +1,16 @@
+require "support/checkers"
+
 RSpec.describe CheckerJobs::Checks::EnsureNo, :bugsnag, :configuration do
   include BugsnagHelpers
 
-  let(:instance) { described_class.new(checker_klass, "ensure_name", {}, block) }
+  let(:instance) { described_class.new(checker_klass, "ensure_name", options, block) }
   let(:checker_klass) do
     Class.new do
       include CheckerJobs::Base
       notify :bugsnag
     end
   end
+  let(:options) { {} }
 
   describe "#perform" do
     subject(:perform) { instance.perform }
@@ -47,5 +50,47 @@
 
       include_examples "does_not_send_a_bugsnag_notification"
     end
+
+    context "when retry option is used" do
+      context "when set to 1 time" do
+        let(:options) { { retry: 1 } }
+
+        context "when block's result is 0" do
+          let(:block) { Proc.new { 0 } }
+
+          include_examples "does_not_send_a_bugsnag_notification"
+        end
+
+        context "when block's result is > 0" do
+          include_context "when SidekiqChecker is available"
+          let(:block) { Proc.new { 2 } }
+
+          it "sends 2 sidekiq jobs" do
+            allow(instance).to receive(:perform).and_call_original
+            perform
+            expect(instance).to have_received(:perform).twice
+          end
+
+          include_examples "sends_a_bugsnag_notification"
+        end
+      end
+
+      context "when set to more than the maximum allowed" do
+        let(:options) { { retry: 8 } }
+
+        context "when block's result is > 0" do
+          include_context "when SidekiqChecker is available"
+          let(:block) { Proc.new { 2 } }
+
+          it "sends 1 more sidekiq jobs than the maximum number of retries" do
+            allow(instance).to receive(:perform).and_call_original
+            perform
+            expect(instance).to have_received(:perform).exactly(4).times
+          end
+
+          include_examples "sends_a_bugsnag_notification"
+        end
+      end
+    end
   end
 end

spec/checker_jobs/notifiers/bugsnag_spec.rb

@@ -23,7 +23,7 @@
     expect(::Bugsnag).to have_received(:deliver_notification).once
   end
 
-  describe "notify's resulting payload" do
+  describe "notifies resulting payload" do
     subject(:notify_report) do
       report = nil
 

spec/support/bugsnag_helpers.rb

@@ -0,0 +1,17 @@
+module BugsnagHelpers
+  shared_examples "sends_a_bugsnag_notification" do
+    it do
+      allow(::Bugsnag).to receive(:deliver_notification)
+      subject
+      expect(::Bugsnag).to have_received(:deliver_notification).once
+    end
+  end
+
+  shared_examples "does_not_send_a_bugsnag_notification" do
+    it do
+      allow(::Bugsnag).to receive(:deliver_notification)
+      subject
+      expect(::Bugsnag).not_to have_received(:deliver_notification)
+    end
+  end
+end