Add raise message to ZenTao client

lib/gitlab/zentao/client.rb

@@ -33,7 +33,7 @@ module Gitlab
       end
 
       def fetch_issue(issue_id)
-        raise Gitlab::Zentao::Client::Error unless issue_id_pattern.match(issue_id)
+        raise Gitlab::Zentao::Client::Error, 'invalid issue id' unless issue_id_pattern.match(issue_id)
 
         get("issues/#{issue_id}")
       end
@@ -48,11 +48,11 @@ module Gitlab
         options = { headers: headers, query: params }
         response = Gitlab::HTTP.get(url(path), options)
 
-        raise Gitlab::Zentao::Client::Error unless response.success?
+        raise Gitlab::Zentao::Client::Error, 'request error' unless response.success?
 
         Gitlab::Json.parse(response.body)
       rescue JSON::ParserError
-        raise Gitlab::Zentao::Client::Error
+        raise Gitlab::Zentao::Client::Error, 'invalid response format'
       end
 
       def url(path)

spec/lib/gitlab/zentao/client_spec.rb

@@ -63,7 +63,7 @@ RSpec.describe Gitlab::Zentao::Client do
       it 'fetches the empty product' do
         expect do
           integration.fetch_product(zentao_integration.zentao_product_xid)
-        end.to raise_error(Gitlab::Zentao::Client::Error)
+        end.to raise_error(Gitlab::Zentao::Client::Error, 'request error')
       end
     end
 
@@ -76,7 +76,7 @@ RSpec.describe Gitlab::Zentao::Client do
       it 'fetches the empty product' do
         expect do
           integration.fetch_product(zentao_integration.zentao_product_xid)
-        end.to raise_error(Gitlab::Zentao::Client::Error)
+        end.to raise_error(Gitlab::Zentao::Client::Error, 'invalid response format')
       end
     end
   end
@@ -111,7 +111,8 @@ RSpec.describe Gitlab::Zentao::Client do
 
       it 'returns empty object' do
         invalid_ids.each do |id|
-          expect { integration.fetch_issue(id) }.to raise_error(Gitlab::Zentao::Client::Error)
+          expect { integration.fetch_issue(id) }
+            .to raise_error(Gitlab::Zentao::Client::Error, 'invalid issue id')
         end
       end
     end