From 8cc892d286ce88e107f3c2b5ffab985a8aa1dc8d Mon Sep 17 00:00:00 2001
From: Anderson Macedo <anderson.krs95@gmail.com>
Date: Sun, 17 Nov 2024 12:02:51 -0300
Subject: [PATCH 1/3] Add helper method to query the latency on the Queue
 object

---
 app/models/solid_queue/queue.rb | 13 +++++++++++++
 test/unit/queue_test.rb         | 21 +++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/app/models/solid_queue/queue.rb b/app/models/solid_queue/queue.rb
index 4cf05bfb..e5308784 100644
--- a/app/models/solid_queue/queue.rb
+++ b/app/models/solid_queue/queue.rb
@@ -40,6 +40,19 @@ def size
       @size ||= ReadyExecution.queued_as(name).count
     end
 
+    def latency
+      @latency = begin
+        now = Time.current
+        oldest_enqueued_at = SolidQueue::ReadyExecution.queued_as(name).minimum(:created_at) || now
+
+        (now - oldest_enqueued_at).to_i
+      end
+    end
+
+    def human_latency
+      ActiveSupport::Duration.build(latency).inspect
+    end
+
     def ==(queue)
       name == queue.name
     end
diff --git a/test/unit/queue_test.rb b/test/unit/queue_test.rb
index f546c8d6..16782abb 100644
--- a/test/unit/queue_test.rb
+++ b/test/unit/queue_test.rb
@@ -2,6 +2,8 @@
 
 class QueueTest < ActiveSupport::TestCase
   setup do
+    freeze_time
+
     5.times do
       AddToBufferJob.perform_later "hey!"
     end
@@ -39,4 +41,23 @@ class QueueTest < ActiveSupport::TestCase
       @default_queue.resume
     end
   end
+
+  test "return latency in seconds on each queue" do
+    travel_to 5.minutes.from_now
+
+    assert_in_delta 5.minutes.to_i, @background_queue.latency, 1.second.to_i
+    assert_equal 0, @default_queue.latency
+
+    travel_to 10.minutes.from_now
+
+    assert_in_delta 15.minutes.to_i, @background_queue.latency, 1.second.to_i
+    assert_equal 0, @default_queue.latency
+  end
+
+  test "return human latency on each queue" do
+    travel_to 5.minutes.from_now
+
+    assert_match /5 minutes/, @background_queue.human_latency
+    assert_match /0 seconds/, @default_queue.human_latency
+  end
 end

From 242fd15c761b235e41838545d120fdfcf3176d1b Mon Sep 17 00:00:00 2001
From: Anderson Macedo <anderson.krs95@gmail.com>
Date: Sun, 1 Dec 2024 11:50:48 -0300
Subject: [PATCH 2/3] Update app/models/solid_queue/queue.rb

Co-authored-by: Rosa Gutierrez <rosa.ge@gmail.com>
---
 app/models/solid_queue/queue.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/app/models/solid_queue/queue.rb b/app/models/solid_queue/queue.rb
index e5308784..b68c910a 100644
--- a/app/models/solid_queue/queue.rb
+++ b/app/models/solid_queue/queue.rb
@@ -43,7 +43,7 @@ def size
     def latency
       @latency = begin
         now = Time.current
-        oldest_enqueued_at = SolidQueue::ReadyExecution.queued_as(name).minimum(:created_at) || now
+        oldest_enqueued_at = ReadyExecution.queued_as(name).minimum(:created_at) || now
 
         (now - oldest_enqueued_at).to_i
       end

From 50003ac5fe776afffa6bf827572c4b1828e1179d Mon Sep 17 00:00:00 2001
From: Anderson Macedo <anderson.krs95@gmail.com>
Date: Sun, 1 Dec 2024 13:16:01 -0300
Subject: [PATCH 3/3] Fix unmemoized method

---
 app/models/solid_queue/queue.rb |  2 +-
 test/unit/queue_test.rb         | 16 ++++++++++++++--
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/app/models/solid_queue/queue.rb b/app/models/solid_queue/queue.rb
index b68c910a..7968d395 100644
--- a/app/models/solid_queue/queue.rb
+++ b/app/models/solid_queue/queue.rb
@@ -41,7 +41,7 @@ def size
     end
 
     def latency
-      @latency = begin
+      @latency ||= begin
         now = Time.current
         oldest_enqueued_at = ReadyExecution.queued_as(name).minimum(:created_at) || now
 
diff --git a/test/unit/queue_test.rb b/test/unit/queue_test.rb
index 16782abb..c89c932c 100644
--- a/test/unit/queue_test.rb
+++ b/test/unit/queue_test.rb
@@ -48,16 +48,28 @@ class QueueTest < ActiveSupport::TestCase
     assert_in_delta 5.minutes.to_i, @background_queue.latency, 1.second.to_i
     assert_equal 0, @default_queue.latency
 
+    @background_queue = SolidQueue::Queue.find_by_name("background")
+    @default_queue = SolidQueue::Queue.find_by_name("default")
     travel_to 10.minutes.from_now
 
     assert_in_delta 15.minutes.to_i, @background_queue.latency, 1.second.to_i
     assert_equal 0, @default_queue.latency
   end
 
+  test "returns memoized latency after the first call" do
+    travel_to 5.minutes.from_now
+
+    assert_in_delta 5.minutes.to_i, @background_queue.latency, 1.second.to_i
+
+    travel_to 10.minutes.from_now
+
+    assert_in_delta 5.minutes.to_i, @background_queue.latency, 1.second.to_i
+  end
+
   test "return human latency on each queue" do
     travel_to 5.minutes.from_now
 
-    assert_match /5 minutes/, @background_queue.human_latency
-    assert_match /0 seconds/, @default_queue.human_latency
+    assert_match (/5 minutes/), @background_queue.human_latency
+    assert_match (/0 seconds/), @default_queue.human_latency
   end
 end