From e14fa80c5a15ac779883adbba4cb79a1c9d646e7 Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Fri, 24 Aug 2018 14:47:55 +0200
Subject: [PATCH 01/15] Render past successful deploys on the releases overview

It's valuable to be able to see at a glance whether a given release has
been successfully deployed to a stage in the past, e.g. when you want to
know if a build stage has completed.
---
 app/helpers/application_helper.rb | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 7ac922a9b2..4ae10eef5b 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -326,9 +326,17 @@ def link_to_chart(name, values)
   def deployed_or_running_list(stages, reference)
     html = "".html_safe
     stages.each do |stage|
-      next unless deploy = stage.deployed_or_running_deploy
-      next unless deploy.references?(reference)
-      label = (deploy.active? ? "label-warning" : "label-success")
+      next unless deploy = stage.deploys.where(reference: reference).last
+
+      label = if deploy == stage.last_successful_deploy
+        "label-success"
+      elsif deploy == stage.active_deploy
+        "label-warning"
+      elsif deploy.succeeded?
+        # Deploy is neither active nor is it the last successful one, but it
+        # succeeded in the past.
+        "label-default"
+      end
 
       text = "".html_safe
       text << stage.name

From dafb8966d0b744d6a64e5c99cee0b81e9d8dbbdb Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Fri, 24 Aug 2018 15:21:45 +0200
Subject: [PATCH 02/15] Fixes

---
 app/helpers/application_helper.rb       | 13 ++++++++-----
 test/helpers/application_helper_test.rb | 14 +++++++++++++-
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 4ae10eef5b..6b69bec0d1 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -326,16 +326,19 @@ def link_to_chart(name, values)
   def deployed_or_running_list(stages, reference)
     html = "".html_safe
     stages.each do |stage|
-      next unless deploy = stage.deploys.where(reference: reference).last
+      # The first deploy is the most recent one.
+      next unless deploy = stage.deploys.where(reference: reference).first
 
-      label = if deploy == stage.last_successful_deploy
-        "label-success"
+      if deploy == stage.last_successful_deploy
+        label = "label-success"
       elsif deploy == stage.active_deploy
-        "label-warning"
+        label = "label-warning"
       elsif deploy.succeeded?
         # Deploy is neither active nor is it the last successful one, but it
         # succeeded in the past.
-        "label-default"
+        label = "label-default"
+      else
+        next
       end
 
       text = "".html_safe
diff --git a/test/helpers/application_helper_test.rb b/test/helpers/application_helper_test.rb
index 655ac68a1d..a096a7d3fb 100644
--- a/test/helpers/application_helper_test.rb
+++ b/test/helpers/application_helper_test.rb
@@ -705,11 +705,23 @@ def render
       assert html.html_safe?
     end
 
-    it "renders succeeded deploys" do
+    it "renders current, succeeded deploys" do
       html = deployed_or_running_list(stage_list, "staging")
       html.must_equal "<span class=\"label label-success release-stage\">Staging</span> "
     end
 
+    it "renders past, succeeded deploys" do
+      # This deploy will be newer.
+      stages(:test_staging).deploys.create!(
+        project: projects(:test),
+        reference: "asdfjkadfsjk",
+        job: jobs(:succeeded_test),
+      )
+
+      html = deployed_or_running_list(stage_list, "staging")
+      html.must_equal "<span class=\"label label-default release-stage\">Staging</span> "
+    end
+
     it "ignores failed deploys" do
       deploys(:succeeded_test).job.update_column(:status, 'failed')
       html = deployed_or_running_list(stage_list, "staging")

From 0be72f74dae177e5b10c9d0e797e817518166a74 Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Mon, 27 Aug 2018 12:31:22 +0200
Subject: [PATCH 03/15] Fix the logic

---
 app/helpers/application_helper.rb | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 6b69bec0d1..a3c3b02a7d 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -322,21 +322,25 @@ def link_to_chart(name, values)
     link_to icon_tag('signal'), url, target: :blank
   end
 
-  # show which stages this reference is deploy(ed+ing) to
+  # Show which stages this reference has been or is currently being deployed to.
   def deployed_or_running_list(stages, reference)
     html = "".html_safe
     stages.each do |stage|
       # The first deploy is the most recent one.
-      next unless deploy = stage.deploys.where(reference: reference).first
+      deploy = stage.deploys.where(reference: reference).first
 
-      if deploy == stage.last_successful_deploy
-        label = "label-success"
-      elsif deploy == stage.active_deploy
+      next if deploy.nil?
+
+      if deploy.running?
         label = "label-warning"
       elsif deploy.succeeded?
-        # Deploy is neither active nor is it the last successful one, but it
-        # succeeded in the past.
-        label = "label-default"
+        if deploy == stage.last_deploy
+          label = "label-success"
+        else
+          # Deploy is neither active nor is it the last successful one, but it
+          # succeeded in the past.
+          label = "label-default"
+        end
       else
         next
       end

From 5fa1cc0b220d36ac7b3272b10afb944de9fc07e7 Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Mon, 27 Aug 2018 12:39:34 +0200
Subject: [PATCH 04/15] Make the test more clear

Don't use a reference that's identical to the stage name, that's
confusing.
---
 test/helpers/application_helper_test.rb | 28 ++++++++++++++-----------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/test/helpers/application_helper_test.rb b/test/helpers/application_helper_test.rb
index a096a7d3fb..0f330c713a 100644
--- a/test/helpers/application_helper_test.rb
+++ b/test/helpers/application_helper_test.rb
@@ -698,6 +698,15 @@ def render
 
   describe "#deployed_or_running_list" do
     let(:stage_list) { [stages(:test_staging)] }
+    let!(:deploy) { create_deploy "v1" }
+
+    def create_deploy(reference)
+      stages(:test_staging).deploys.create!(
+        project: projects(:test),
+        reference: reference,
+        job: jobs(:succeeded_test),
+      )
+    end
 
     it "produces safe output" do
       html = deployed_or_running_list([], "foo")
@@ -706,37 +715,32 @@ def render
     end
 
     it "renders current, succeeded deploys" do
-      html = deployed_or_running_list(stage_list, "staging")
+      html = deployed_or_running_list(stage_list, "v1")
       html.must_equal "<span class=\"label label-success release-stage\">Staging</span> "
     end
 
     it "renders past, succeeded deploys" do
       # This deploy will be newer.
-      stages(:test_staging).deploys.create!(
-        project: projects(:test),
-        reference: "asdfjkadfsjk",
-        job: jobs(:succeeded_test),
-      )
+      create_deploy "v2"
 
-      html = deployed_or_running_list(stage_list, "staging")
+      html = deployed_or_running_list(stage_list, "v1")
       html.must_equal "<span class=\"label label-default release-stage\">Staging</span> "
     end
 
     it "ignores failed deploys" do
-      deploys(:succeeded_test).job.update_column(:status, 'failed')
-      html = deployed_or_running_list(stage_list, "staging")
+      deploys(:succeeded_test).job.update_column(:status, "failed")
+      html = deployed_or_running_list(stage_list, "v1")
       html.must_equal ""
     end
 
     it "ignores non-matching deploys" do
-      deploys(:succeeded_test).update_column(:reference, 'nope')
-      html = deployed_or_running_list(stage_list, "staging")
+      html = deployed_or_running_list(stage_list, "yolo")
       html.must_equal ""
     end
 
     it "shows active deploys" do
       deploys(:succeeded_test).job.update_column(:status, 'running')
-      html = deployed_or_running_list(stage_list, "staging")
+      html = deployed_or_running_list(stage_list, "v1")
       html.must_equal "<span class=\"label label-warning release-stage\">Staging</span> "
     end
   end

From 05ed49c629a256e8ec6de948b4e49f526de01cb6 Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Mon, 27 Aug 2018 12:43:59 +0200
Subject: [PATCH 05/15] Add test to avoid introducing new queries

---
 test/helpers/application_helper_test.rb | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/test/helpers/application_helper_test.rb b/test/helpers/application_helper_test.rb
index 0f330c713a..d85b7a1865 100644
--- a/test/helpers/application_helper_test.rb
+++ b/test/helpers/application_helper_test.rb
@@ -728,7 +728,7 @@ def create_deploy(reference)
     end
 
     it "ignores failed deploys" do
-      deploys(:succeeded_test).job.update_column(:status, "failed")
+      deploy.job.update_column(:status, "failed")
       html = deployed_or_running_list(stage_list, "v1")
       html.must_equal ""
     end
@@ -739,10 +739,30 @@ def create_deploy(reference)
     end
 
     it "shows active deploys" do
-      deploys(:succeeded_test).job.update_column(:status, 'running')
+      deploy.job.update_column(:status, 'running')
       html = deployed_or_running_list(stage_list, "v1")
       html.must_equal "<span class=\"label label-warning release-stage\">Staging</span> "
     end
+
+    it "uses 3 queries when the deploy is the most recent one on the stage" do
+      assert_sql_queries 3 do
+        deployed_or_running_list(stage_list, "v1")
+      end
+    end
+
+    it "uses 2 queries if the deploy is currently running" do
+      deploy.job.update_column(:status, "running")
+
+      assert_sql_queries 2 do
+        deployed_or_running_list(stage_list, "v1")
+      end
+    end
+
+    it "uses 1 query if there have been no deploys of that reference" do
+      assert_sql_queries 1 do
+        deployed_or_running_list(stage_list, "yolo")
+      end
+    end
   end
 
   describe "#check_box_section" do

From cbf600cff8073456db41ecd9c7bf7b5f60fb23a5 Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Mon, 27 Aug 2018 13:34:44 +0200
Subject: [PATCH 06/15] Rubocop fix

---
 test/helpers/application_helper_test.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/helpers/application_helper_test.rb b/test/helpers/application_helper_test.rb
index d85b7a1865..79f16d8e6c 100644
--- a/test/helpers/application_helper_test.rb
+++ b/test/helpers/application_helper_test.rb
@@ -704,7 +704,7 @@ def create_deploy(reference)
       stages(:test_staging).deploys.create!(
         project: projects(:test),
         reference: reference,
-        job: jobs(:succeeded_test),
+        job: jobs(:succeeded_test)
       )
     end
 

From 7b74fe58dfc44ed7ba8492a4fe4f55ac783c134f Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Mon, 27 Aug 2018 15:19:06 +0200
Subject: [PATCH 07/15] Simplify HTML generation

---
 app/helpers/application_helper.rb | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index a3c3b02a7d..ee2454b529 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -324,33 +324,33 @@ def link_to_chart(name, values)
 
   # Show which stages this reference has been or is currently being deployed to.
   def deployed_or_running_list(stages, reference)
-    html = "".html_safe
-    stages.each do |stage|
+    pieces = stages.map do |stage|
       # The first deploy is the most recent one.
       deploy = stage.deploys.where(reference: reference).first
 
-      next if deploy.nil?
-
-      if deploy.running?
-        label = "label-warning"
+      label = if deploy.nil?
+        nil
+      elsif deploy.running?
+        "label-warning"
       elsif deploy.succeeded?
         if deploy == stage.last_deploy
-          label = "label-success"
+          "label-success"
         else
           # Deploy is neither active nor is it the last successful one, but it
           # succeeded in the past.
-          label = "label-default"
+          "label-default"
         end
       else
-        next
+        nil
       end
 
-      text = "".html_safe
-      text << stage.name
-      html << content_tag(:span, text, class: "label #{label} release-stage")
-      html << " "
+      if label.present?
+        text = stage.name.html_safe
+        content_tag(:span, text, class: "label #{label} release-stage")
+      end
     end
-    html
+
+    safe_join(pieces, " ")
   end
 
   def check_box_section(section_title, help_text, object, method, collection)

From 77378b157aba28b33264a6a9a656d4b2ec97cb28 Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Mon, 27 Aug 2018 15:36:31 +0200
Subject: [PATCH 08/15] Rubocop fix

---
 app/helpers/application_helper.rb | 2 --
 1 file changed, 2 deletions(-)

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index ee2454b529..6f1d45920b 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -340,8 +340,6 @@ def deployed_or_running_list(stages, reference)
           # succeeded in the past.
           "label-default"
         end
-      else
-        nil
       end
 
       if label.present?

From 472863c288400be5918677ca28be450c71ddeadb Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Mon, 27 Aug 2018 15:37:55 +0200
Subject: [PATCH 09/15] Fix test

---
 test/helpers/application_helper_test.rb | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/test/helpers/application_helper_test.rb b/test/helpers/application_helper_test.rb
index 79f16d8e6c..57cfa49829 100644
--- a/test/helpers/application_helper_test.rb
+++ b/test/helpers/application_helper_test.rb
@@ -716,7 +716,7 @@ def create_deploy(reference)
 
     it "renders current, succeeded deploys" do
       html = deployed_or_running_list(stage_list, "v1")
-      html.must_equal "<span class=\"label label-success release-stage\">Staging</span> "
+      html.must_equal "<span class=\"label label-success release-stage\">Staging</span>"
     end
 
     it "renders past, succeeded deploys" do
@@ -724,7 +724,7 @@ def create_deploy(reference)
       create_deploy "v2"
 
       html = deployed_or_running_list(stage_list, "v1")
-      html.must_equal "<span class=\"label label-default release-stage\">Staging</span> "
+      html.must_equal "<span class=\"label label-default release-stage\">Staging</span>"
     end
 
     it "ignores failed deploys" do
@@ -741,7 +741,7 @@ def create_deploy(reference)
     it "shows active deploys" do
       deploy.job.update_column(:status, 'running')
       html = deployed_or_running_list(stage_list, "v1")
-      html.must_equal "<span class=\"label label-warning release-stage\">Staging</span> "
+      html.must_equal "<span class=\"label label-warning release-stage\">Staging</span>"
     end
 
     it "uses 3 queries when the deploy is the most recent one on the stage" do

From e52df042b21a9946fd456bfa9b480c530559ed9c Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Tue, 28 Aug 2018 13:27:08 +0200
Subject: [PATCH 10/15] Feedback fixes

---
 app/helpers/application_helper.rb | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 6f1d45920b..88ffab6e9d 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -342,8 +342,9 @@ def deployed_or_running_list(stages, reference)
         end
       end
 
-      if label.present?
-        text = stage.name.html_safe
+      if label
+        text = "".html_safe
+        text << stage.name
         content_tag(:span, text, class: "label #{label} release-stage")
       end
     end

From 4b13fa6d3e38476fb7f54cdb782a653c1dbea0de Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Tue, 28 Aug 2018 14:13:45 +0200
Subject: [PATCH 11/15] Optimize the loading of deploys per release

---
 app/helpers/application_helper.rb |  5 +--
 app/models/deploy.rb              | 14 ++++++++
 test/models/deploy_test.rb        | 55 +++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 88ffab6e9d..ff096ce5b9 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -324,9 +324,10 @@ def link_to_chart(name, values)
 
   # Show which stages this reference has been or is currently being deployed to.
   def deployed_or_running_list(stages, reference)
+    deploys = Deploy.of_reference_in_stages(reference, stages)
+
     pieces = stages.map do |stage|
-      # The first deploy is the most recent one.
-      deploy = stage.deploys.where(reference: reference).first
+      deploy = deploys[stage]
 
       label = if deploy.nil?
         nil
diff --git a/app/models/deploy.rb b/app/models/deploy.rb
index 1faecc22d3..06152a981a 100644
--- a/app/models/deploy.rb
+++ b/app/models/deploy.rb
@@ -171,6 +171,20 @@ def self.after(deploy)
     where("#{table_name}.id > ?", deploy.id)
   end
 
+  def self.in_stages(stages)
+    where(stage_id: stages.map(&:id))
+  end
+
+  # Returns a Hash of Stage => Deploy for the given reference and stages.
+  def self.of_reference_in_stages(reference, stages)
+    where(reference: reference).in_stages(stages).group(:stage_id).map do |deploy|
+      # Don't trigger another query in order to fetch the stage.
+      stage = stages.find { |stage| stage.id == deploy.stage_id }
+
+      [stage, deploy]
+    end.to_h
+  end
+
   def self.expired
     threshold = BuddyCheck.time_limit.ago
     stale = where(buddy_id: nil).joins(:job).where(jobs: {status: 'pending'}).where("jobs.created_at < ?", threshold)
diff --git a/test/models/deploy_test.rb b/test/models/deploy_test.rb
index 37bb6ef859..ad34099e29 100644
--- a/test/models/deploy_test.rb
+++ b/test/models/deploy_test.rb
@@ -656,6 +656,52 @@ def deploy
     end
   end
 
+  describe "#in_stages" do
+    it "shows only deploys in the specified stages" do
+      stage1 = create_stage!(name: "stage1")
+      stage2 = create_stage!(name: "stage2")
+
+      deploy1 = create_deploy!(stage: stage1)
+      deploy2 = create_deploy!(stage: stage2)
+      deploy3 = create_deploy!(stage: stage1)
+
+      Deploy.in_stages([stage1]).pluck(:id).sort.must_equal [deploy1.id, deploy3.id].sort
+    end
+  end
+
+  describe "#of_reference_in_stages" do
+    it "returns the latest deploy with the given reference in the specified stages" do
+      stage1 = create_stage!(name: "stage1")
+      stage2 = create_stage!(name: "stage2")
+      stage3 = create_stage!(name: "stage3")
+
+      deploy1 = create_deploy!(stage: stage1, reference: "v42")
+      deploy2 = create_deploy!(stage: stage1, reference: "v42")
+      deploy3 = create_deploy!(stage: stage2, reference: "v42")
+      deploy4 = create_deploy!(stage: stage3, reference: "v42")
+
+      expected = {
+        stage1 => deploy2,
+        stage2 => deploy3
+      }
+
+      Deploy.of_reference_in_stages("v42", [stage1, stage2]).must_equal expected
+    end
+
+    it "uses a single query" do
+      stage1 = create_stage!(name: "stage1")
+      stage2 = create_stage!(name: "stage2")
+
+      create_deploy!(stage: stage1, reference: "v42")
+      create_deploy!(stage: stage1, reference: "v42")
+      create_deploy!(stage: stage2, reference: "v42")
+
+      assert_sql_queries 1 do
+        Deploy.of_reference_in_stages("v42", [stage1, stage2])
+      end
+    end
+  end
+
   describe "#as_json" do
     it "includes simple methods status" do
       deploy.as_json.fetch("status").must_equal "succeeded"
@@ -690,4 +736,13 @@ def create_job!(attrs = {})
 
     Job.create!(default_attrs.merge(attrs))
   end
+
+  def create_stage!(attrs = {})
+    default_attrs = {
+      project: project,
+      name: "some-stage"
+    }
+
+    Stage.create!(default_attrs.merge(attrs))
+  end
 end

From fcd7d967c418da164db7c3b2545219a7ddc4405d Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Tue, 28 Aug 2018 14:47:41 +0200
Subject: [PATCH 12/15] Rubocop fix

---
 test/models/deploy_test.rb | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/test/models/deploy_test.rb b/test/models/deploy_test.rb
index ad34099e29..e30cf1f6c8 100644
--- a/test/models/deploy_test.rb
+++ b/test/models/deploy_test.rb
@@ -675,14 +675,14 @@ def deploy
       stage2 = create_stage!(name: "stage2")
       stage3 = create_stage!(name: "stage3")
 
+      create_deploy!(stage: stage1, reference: "v42")
       deploy1 = create_deploy!(stage: stage1, reference: "v42")
-      deploy2 = create_deploy!(stage: stage1, reference: "v42")
-      deploy3 = create_deploy!(stage: stage2, reference: "v42")
-      deploy4 = create_deploy!(stage: stage3, reference: "v42")
+      deploy2 = create_deploy!(stage: stage2, reference: "v42")
+      create_deploy!(stage: stage3, reference: "v42")
 
       expected = {
-        stage1 => deploy2,
-        stage2 => deploy3
+        stage1 => deploy1,
+        stage2 => deploy2
       }
 
       Deploy.of_reference_in_stages("v42", [stage1, stage2]).must_equal expected

From af6e1079634c93aee3090ba05cd9f75c17f5fbf4 Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Tue, 28 Aug 2018 14:57:25 +0200
Subject: [PATCH 13/15] Fix the lookup method

We need two queries.
---
 app/models/deploy.rb       | 12 +++++++++++-
 test/models/deploy_test.rb |  4 ++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/app/models/deploy.rb b/app/models/deploy.rb
index 06152a981a..4a5a735b57 100644
--- a/app/models/deploy.rb
+++ b/app/models/deploy.rb
@@ -177,7 +177,17 @@ def self.in_stages(stages)
 
   # Returns a Hash of Stage => Deploy for the given reference and stages.
   def self.of_reference_in_stages(reference, stages)
-    where(reference: reference).in_stages(stages).group(:stage_id).map do |deploy|
+    # Group by stage, then select the latest deploy id.
+    deploys_and_stages = where(reference: reference).
+      in_stages(stages).
+      group(:stage_id).
+      select("MAX(id) AS id, stage_id")
+
+    # Fetch the actual deploys.
+    deploys = Deploy.where(id: deploys_and_stages.map(&:id))
+
+    # Map to a hash of stage => deploy entries.
+    deploys.map do |deploy|
       # Don't trigger another query in order to fetch the stage.
       stage = stages.find { |stage| stage.id == deploy.stage_id }
 
diff --git a/test/models/deploy_test.rb b/test/models/deploy_test.rb
index e30cf1f6c8..1eeae31f86 100644
--- a/test/models/deploy_test.rb
+++ b/test/models/deploy_test.rb
@@ -688,7 +688,7 @@ def deploy
       Deploy.of_reference_in_stages("v42", [stage1, stage2]).must_equal expected
     end
 
-    it "uses a single query" do
+    it "uses only two queries" do
       stage1 = create_stage!(name: "stage1")
       stage2 = create_stage!(name: "stage2")
 
@@ -696,7 +696,7 @@ def deploy
       create_deploy!(stage: stage1, reference: "v42")
       create_deploy!(stage: stage2, reference: "v42")
 
-      assert_sql_queries 1 do
+      assert_sql_queries 2 do
         Deploy.of_reference_in_stages("v42", [stage1, stage2])
       end
     end

From f1f63422346a37913ce50d8dc95ac2f76055541e Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Wed, 29 Aug 2018 12:36:59 +0200
Subject: [PATCH 14/15] Inline `in_stages`

---
 app/models/deploy.rb       |  6 +-----
 test/models/deploy_test.rb | 13 -------------
 2 files changed, 1 insertion(+), 18 deletions(-)

diff --git a/app/models/deploy.rb b/app/models/deploy.rb
index 4a5a735b57..b54abe0e7a 100644
--- a/app/models/deploy.rb
+++ b/app/models/deploy.rb
@@ -171,15 +171,11 @@ def self.after(deploy)
     where("#{table_name}.id > ?", deploy.id)
   end
 
-  def self.in_stages(stages)
-    where(stage_id: stages.map(&:id))
-  end
-
   # Returns a Hash of Stage => Deploy for the given reference and stages.
   def self.of_reference_in_stages(reference, stages)
     # Group by stage, then select the latest deploy id.
     deploys_and_stages = where(reference: reference).
-      in_stages(stages).
+      where(stage_id: stages.map(&:id)).
       group(:stage_id).
       select("MAX(id) AS id, stage_id")
 
diff --git a/test/models/deploy_test.rb b/test/models/deploy_test.rb
index 1eeae31f86..199194cbf8 100644
--- a/test/models/deploy_test.rb
+++ b/test/models/deploy_test.rb
@@ -656,19 +656,6 @@ def deploy
     end
   end
 
-  describe "#in_stages" do
-    it "shows only deploys in the specified stages" do
-      stage1 = create_stage!(name: "stage1")
-      stage2 = create_stage!(name: "stage2")
-
-      deploy1 = create_deploy!(stage: stage1)
-      deploy2 = create_deploy!(stage: stage2)
-      deploy3 = create_deploy!(stage: stage1)
-
-      Deploy.in_stages([stage1]).pluck(:id).sort.must_equal [deploy1.id, deploy3.id].sort
-    end
-  end
-
   describe "#of_reference_in_stages" do
     it "returns the latest deploy with the given reference in the specified stages" do
       stage1 = create_stage!(name: "stage1")

From 6ff52b374bb656faf2be498eaf6b489b76170dcf Mon Sep 17 00:00:00 2001
From: Daniel Schierbeck <daniel.schierbeck@gmail.com>
Date: Wed, 29 Aug 2018 17:36:19 +0200
Subject: [PATCH 15/15] Update the query counts

---
 test/helpers/application_helper_test.rb | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/test/helpers/application_helper_test.rb b/test/helpers/application_helper_test.rb
index 57cfa49829..9ba216346b 100644
--- a/test/helpers/application_helper_test.rb
+++ b/test/helpers/application_helper_test.rb
@@ -744,22 +744,22 @@ def create_deploy(reference)
       html.must_equal "<span class=\"label label-warning release-stage\">Staging</span>"
     end
 
-    it "uses 3 queries when the deploy is the most recent one on the stage" do
-      assert_sql_queries 3 do
+    it "uses 4 queries when the deploy is the most recent one on the stage" do
+      assert_sql_queries 4 do
         deployed_or_running_list(stage_list, "v1")
       end
     end
 
-    it "uses 2 queries if the deploy is currently running" do
+    it "uses 3 queries if the deploy is currently running" do
       deploy.job.update_column(:status, "running")
 
-      assert_sql_queries 2 do
+      assert_sql_queries 3 do
         deployed_or_running_list(stage_list, "v1")
       end
     end
 
-    it "uses 1 query if there have been no deploys of that reference" do
-      assert_sql_queries 1 do
+    it "uses 2 queries if there have been no deploys of that reference" do
+      assert_sql_queries 2 do
         deployed_or_running_list(stage_list, "yolo")
       end
     end