Paginate Bitbucket Server importer projects

To prevent delays in loading the page and reduce memory usage, limit the
number of projects shown at 25 per page.

Part of https://gitlab.com/gitlab-org/gitlab-ce/issues/50021

3 files changed, 48 insertions, 3 deletions

diff --git a/spec/lib/bitbucket_server/client_spec.rb b/spec/lib/bitbucket_server/client_spec.rb
index f926ae963a4..5de0a9a65b5 100644
--- a/spec/lib/bitbucket_server/client_spec.rb
+++ b/spec/lib/bitbucket_server/client_spec.rb
@@ -13,7 +13,7 @@ describe BitbucketServer::Client do
     let(:path) { "/projects/#{project}/repos/#{repo_slug}/pull-requests?state=ALL" }
 
     it 'requests a collection' do
-      expect(BitbucketServer::Paginator).to receive(:new).with(anything, path, :pull_request)
+      expect(BitbucketServer::Paginator).to receive(:new).with(anything, path, :pull_request, page_offset: 0, limit: nil)
 
       subject.pull_requests(project, repo_slug)
     end
@@ -29,7 +29,7 @@ describe BitbucketServer::Client do
     let(:path) { "/projects/#{project}/repos/#{repo_slug}/pull-requests/1/activities" }
 
     it 'requests a collection' do
-      expect(BitbucketServer::Paginator).to receive(:new).with(anything, path, :activity)
+      expect(BitbucketServer::Paginator).to receive(:new).with(anything, path, :activity, page_offset: 0, limit: nil)
 
       subject.activities(project, repo_slug, 1)
     end
@@ -52,10 +52,16 @@ describe BitbucketServer::Client do
     let(:path) { "/repos" }
 
     it 'requests a collection' do
-      expect(BitbucketServer::Paginator).to receive(:new).with(anything, path, :repo)
+      expect(BitbucketServer::Paginator).to receive(:new).with(anything, path, :repo, page_offset: 0, limit: nil)
 
       subject.repos
     end
+
+    it 'requests a collection with an offset and limit' do
+      expect(BitbucketServer::Paginator).to receive(:new).with(anything, path, :repo, page_offset: 10, limit: 25)
+
+      subject.repos(page_offset: 10, limit: 25)
+    end
   end
 
   describe '#create_branch' do
diff --git a/spec/lib/bitbucket_server/collection_spec.rb b/spec/lib/bitbucket_server/collection_spec.rb
new file mode 100644
index 00000000000..ddd02bac88a
--- /dev/null
+++ b/spec/lib/bitbucket_server/collection_spec.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe BitbucketServer::Collection do
+  let(:connection) { instance_double(BitbucketServer::Connection) }
+  let(:page) { 1 }
+  let(:paginator) { BitbucketServer::Paginator.new(connection, 'http://more-data', :pull_request, page_offset: page) }
+
+  subject { described_class.new(paginator) }
+
+  describe '#current_page' do
+    it 'returns 1' do
+      expect(subject.current_page).to eq(1)
+    end
+  end
+
+  describe '#prev_page' do
+    it 'returns nil' do
+      expect(subject.prev_page).to be_nil
+    end
+  end
+
+  describe '#next_page' do
+    it 'returns 2' do
+      expect(subject.next_page).to eq(2)
+    end
+  end
+end
diff --git a/spec/lib/bitbucket_server/paginator_spec.rb b/spec/lib/bitbucket_server/paginator_spec.rb
index 2de50eba3c4..d268d4f23cf 100644
--- a/spec/lib/bitbucket_server/paginator_spec.rb
+++ b/spec/lib/bitbucket_server/paginator_spec.rb
@@ -20,6 +20,16 @@ describe BitbucketServer::Paginator do
       expect { paginator.items }.to raise_error(StopIteration)
     end
 
+    it 'obeys limits' do
+      limited = described_class.new(connection, 'http://more-data', :pull_request, page_offset: 0, limit: 1)
+      allow(limited).to receive(:fetch_next_page).and_return(first_page)
+
+      expect(limited.has_next_page?).to be_truthy
+      expect(limited.items).to match(['item_1'])
+      expect(limited.has_next_page?).to be_truthy
+      expect { limited.items }.to raise_error(StopIteration)
+    end
+
     it 'calls the connection with different offsets' do
       expect(connection).to receive(:get).with('http://more-data', start: 0, limit: BitbucketServer::Paginator::PAGE_LENGTH).and_return(page_attrs)