From f0bfe4c2a76168c6e85bed4ab06360f6654fcca0 Mon Sep 17 00:00:00 2001
From: Jeremy Bopp <jbopp@indeed.com>
Date: Fri, 19 Jun 2020 16:42:58 -0500
Subject: [PATCH 1/2] Simplify pagination using Enumerator::Lazy

---
 lib/gitlab/paginated_response.rb       | 43 +++++++-------------------
 spec/gitlab/paginated_response_spec.rb | 23 ++++++++++++--
 2 files changed, 33 insertions(+), 33 deletions(-)

diff --git a/lib/gitlab/paginated_response.rb b/lib/gitlab/paginated_response.rb
index ef06b80eb..e4e652828 100644
--- a/lib/gitlab/paginated_response.rb
+++ b/lib/gitlab/paginated_response.rb
@@ -42,37 +42,18 @@ def each_page
       end
     end
 
-    def auto_paginate
-      response = block_given? ? nil : []
-      each_page do |page|
-        if block_given?
-          page.each do |item|
-            yield item
-          end
-        else
-          response += page
-        end
-      end
-      response
-    end
-
-    def paginate_with_limit(limit)
-      response = block_given? ? nil : []
-      count = 0
-      each_page do |page|
-        if block_given?
-          page.each do |item|
-            yield item
-            count += 1
-            break if count >= limit
-          end
-        else
-          response += page[0, limit - count]
-          count = response.length
-        end
-        break if count >= limit
-      end
-      response
+    def lazy_paginate(&b)
+      to_enum(:each_page).lazy.flat_map(&:to_ary)
+    end
+
+    def auto_paginate(&b)
+      return lazy_paginate.to_a unless block_given?
+      lazy_paginate.each(&b)
+    end
+
+    def paginate_with_limit(limit, &b)
+      return lazy_paginate.take(limit).to_a unless block_given?
+      lazy_paginate.take(limit).each(&b)
     end
 
     def last_page?
diff --git a/spec/gitlab/paginated_response_spec.rb b/spec/gitlab/paginated_response_spec.rb
index 09e99acae..97119da62 100644
--- a/spec/gitlab/paginated_response_spec.rb
+++ b/spec/gitlab/paginated_response_spec.rb
@@ -63,6 +63,25 @@
     end
   end
 
+  describe '.lazy_paginate' do
+    it 'returns a lazy enumerator' do
+      expect(@paginated_response.lazy_paginate).to be_an(Enumerator::Lazy)
+    end
+
+    it 'only requests needed pages' do
+      next_page = double('next_page')
+      allow(@paginated_response).to receive(:has_next_page?).and_return(true)
+      allow(@paginated_response).to receive(:next_page).and_return(next_page)
+      allow(next_page).to receive(:has_next_page?).and_return(true)
+      # NOTE:
+      # Do not define :next_page on the next_page double to prove that it is NOT
+      # called even though :has_next_page? has been defined to claim another
+      # page is available.
+      allow(next_page).to receive(:to_ary).and_return([5, 6, 7, 8])
+      expect(@paginated_response.lazy_paginate.take(8)).to contain_exactly(1, 2, 3, 4, 5, 6, 7, 8)
+    end
+  end
+
   describe '.auto_paginate' do
     it 'returns an array if block is not given' do
       next_page = double('next_page')
@@ -104,7 +123,7 @@
       allow(@paginated_response).to receive(:has_next_page?).and_return(true)
       allow(@paginated_response).to receive(:next_page).and_return(next_page)
       allow(next_page).to receive(:has_next_page?).and_return(false)
-      allow(next_page).to receive(:[]).with(0, 1).and_return([5])
+      allow(next_page).to receive(:to_ary).and_return([5])
       expect(@paginated_response.paginate_with_limit(5)).to contain_exactly(1, 2, 3, 4, 5)
     end
   end
@@ -115,7 +134,7 @@
       allow(@paginated_response).to receive(:has_next_page?).and_return(true)
       allow(@paginated_response).to receive(:next_page).and_return(next_page)
       allow(next_page).to receive(:has_next_page?).and_return(false)
-      allow(next_page).to receive(:each).and_yield(5).and_yield(6).and_yield(7).and_yield(8)
+      allow(next_page).to receive(:to_ary).and_return([5, 6, 7, 8])
     end
   end
 

From 59bf7eb106533e26f8a38e2f6e8060683e949838 Mon Sep 17 00:00:00 2001
From: Jeremy Bopp <jbopp@indeed.com>
Date: Mon, 22 Jun 2020 18:22:30 -0500
Subject: [PATCH 2/2] Satisfy Rubocop requirement on method parameter name
 length

---
 lib/gitlab/paginated_response.rb | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/gitlab/paginated_response.rb b/lib/gitlab/paginated_response.rb
index e4e652828..07b7e91f9 100644
--- a/lib/gitlab/paginated_response.rb
+++ b/lib/gitlab/paginated_response.rb
@@ -42,18 +42,20 @@ def each_page
       end
     end
 
-    def lazy_paginate(&b)
+    def lazy_paginate
       to_enum(:each_page).lazy.flat_map(&:to_ary)
     end
 
-    def auto_paginate(&b)
+    def auto_paginate(&block)
       return lazy_paginate.to_a unless block_given?
-      lazy_paginate.each(&b)
+
+      lazy_paginate.each(&block)
     end
 
-    def paginate_with_limit(limit, &b)
+    def paginate_with_limit(limit, &block)
       return lazy_paginate.take(limit).to_a unless block_given?
-      lazy_paginate.take(limit).each(&b)
+
+      lazy_paginate.take(limit).each(&block)
     end
 
     def last_page?