1 files changed, 157 insertions, 0 deletions
diff --git a/spec/lib/gitlab/pagination_delegate_spec.rb b/spec/lib/gitlab/pagination_delegate_spec.rb
new file mode 100644
index 00000000000..7693decd881
--- /dev/null
+++ b/spec/lib/gitlab/pagination_delegate_spec.rb
@@ -0,0 +1,157 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::PaginationDelegate do
+  context 'when there is no data' do
+    let(:delegate) do
+      described_class.new(page: 1,
+                          per_page: 10,
+                          count: 0)
+    end
+
+    it 'shows the correct total count' do
+      expect(delegate.total_count).to eq(0)
+    end
+
+    it 'shows the correct total pages' do
+      expect(delegate.total_pages).to eq(0)
+    end
+
+    it 'shows the correct next page' do
+      expect(delegate.next_page).to be_nil
+    end
+
+    it 'shows the correct previous page' do
+      expect(delegate.prev_page).to be_nil
+    end
+
+    it 'shows the correct current page' do
+      expect(delegate.current_page).to eq(1)
+    end
+
+    it 'shows the correct limit value' do
+      expect(delegate.limit_value).to eq(10)
+    end
+
+    it 'shows the correct first page' do
+      expect(delegate.first_page?).to be true
+    end
+
+    it 'shows the correct last page' do
+      expect(delegate.last_page?).to be true
+    end
+
+    it 'shows the correct offset' do
+      expect(delegate.offset).to eq(0)
+    end
+  end
+
+  context 'with data' do
+    let(:delegate) do
+      described_class.new(page: 5,
+                          per_page: 100,
+                          count: 1000)
+    end
+
+    it 'shows the correct total count' do
+      expect(delegate.total_count).to eq(1000)
+    end
+
+    it 'shows the correct total pages' do
+      expect(delegate.total_pages).to eq(10)
+    end
+
+    it 'shows the correct next page' do
+      expect(delegate.next_page).to eq(6)
+    end
+
+    it 'shows the correct previous page' do
+      expect(delegate.prev_page).to eq(4)
+    end
+
+    it 'shows the correct current page' do
+      expect(delegate.current_page).to eq(5)
+    end
+
+    it 'shows the correct limit value' do
+      expect(delegate.limit_value).to eq(100)
+    end
+
+    it 'shows the correct first page' do
+      expect(delegate.first_page?).to be false
+    end
+
+    it 'shows the correct last page' do
+      expect(delegate.last_page?).to be false
+    end
+
+    it 'shows the correct offset' do
+      expect(delegate.offset).to eq(400)
+    end
+  end
+
+  context 'for last page' do
+    let(:delegate) do
+      described_class.new(page: 10,
+                          per_page: 100,
+                          count: 1000)
+    end
+
+    it 'shows the correct total count' do
+      expect(delegate.total_count).to eq(1000)
+    end
+
+    it 'shows the correct total pages' do
+      expect(delegate.total_pages).to eq(10)
+    end
+
+    it 'shows the correct next page' do
+      expect(delegate.next_page).to be_nil
+    end
+
+    it 'shows the correct previous page' do
+      expect(delegate.prev_page).to eq(9)
+    end
+
+    it 'shows the correct current page' do
+      expect(delegate.current_page).to eq(10)
+    end
+
+    it 'shows the correct limit value' do
+      expect(delegate.limit_value).to eq(100)
+    end
+
+    it 'shows the correct first page' do
+      expect(delegate.first_page?).to be false
+    end
+
+    it 'shows the correct last page' do
+      expect(delegate.last_page?).to be true
+    end
+
+    it 'shows the correct offset' do
+      expect(delegate.offset).to eq(900)
+    end
+  end
+
+  context 'with limits and defaults' do
+    it 'has a maximum limit per page' do
+      expect(described_class.new(page: nil,
+                                 per_page: 1000,
+                                 count: 0).limit_value).to eq(described_class::MAX_PER_PAGE)
+    end
+
+    it 'has a default per page' do
+      expect(described_class.new(page: nil,
+                                 per_page: nil,
+                                 count: 0).limit_value).to eq(described_class::DEFAULT_PER_PAGE)
+    end
+
+    it 'has a maximum page' do
+      expect(described_class.new(page: 100,
+                                 per_page: 10,
+                                 count: 1).current_page).to eq(1)
+    end
+  end
+end