add test for pagination caching

Author: jtarchie

spec/commands/check_spec.rb

@@ -85,4 +85,40 @@ def stub_json(uri, body)
       end
     end
   end
+
+  context 'when paginating through many PRs' do
+    def stub_body_json(uri, body, headers={})
+      stub_request(:get, uri)
+        .to_return(headers: {
+          'Content-Type' => 'application/json',
+          'ETag' => Digest::MD5.hexdigest(body.to_json),
+      }.merge(headers), body: body.to_json)
+    end
+
+    def stub_cache_json(uri)
+      stub_request(:get, uri)
+        .to_return(status: 304, body: '[]')
+    end
+
+    it 'uses the cache that already exists' do
+      pull_requests = (1..100).map do |i|
+        { number: i, head: { sha: "abcdef-#{i}", repo: { full_name: 'jtarchie/test' } }, base: { repo: { full_name: 'jtarchie/test' } } }
+      end
+      stub_body_json('https://api.github.com/repos/jtarchie/test/pulls?direction=asc&per_page=100&sort=updated&state=open', pull_requests[0..49], {
+          'Link' => "<https://api.github.com/repos/jtarchie/test/pulls?direction=asc&per_page=100&sort=updated&state=open&page=2>; rel=\"next\""
+      })
+      stub_body_json('https://api.github.com/repos/jtarchie/test/pulls?direction=asc&per_page=100&sort=updated&state=open&page=2', pull_requests[50..99])
+
+      first_prs = check('source' => { 'repo' => 'jtarchie/test' } )
+      expect(first_prs.length).to eq 100
+      Billy.proxy.reset
+
+      stub_cache_json('https://api.github.com/repos/jtarchie/test/pulls?direction=asc&per_page=100&sort=updated&state=open')
+      stub_cache_json('https://api.github.com/repos/jtarchie/test/pulls?direction=asc&per_page=100&sort=updated&state=open&page=2')
+      second_prs = check('source' => { 'repo' => 'jtarchie/test' } )
+
+      expect(first_prs).to eq second_prs
+      # expect A == B
+    end
+  end
 end