Merge pull request #147 from Metallion/display-error-msgs

Include the error messages when we fail due to too many errors.

lib/redlock/client.rb

@@ -319,7 +319,8 @@ def lock_instances(resource, ttl, options)
         @servers.each { |s| s.unlock(resource, value) }
 
         if errors.size >= @quorum
-          raise LockAcquisitionError.new('Too many Redis errors prevented lock acquisition', errors)
+          err_msgs = errors.map { |e| "#{e.class}: #{e.message}" }.join("\n")
+          raise LockAcquisitionError.new("Too many Redis errors prevented lock acquisition:\n#{err_msgs}", errors)
         end
 
         false

spec/client_spec.rb

@@ -108,9 +108,19 @@
         it 'fails to acquire a lock if majority of Redis instances are not available' do
           redlock = Redlock::Client.new(servers_without_quorum)
 
+          expected_msg = <<~MSG
+            failed to acquire lock on 'Too many Redis errors prevented lock acquisition:
+            RedisClient::CannotConnectError: Connection refused - connect(2) for 127.0.0.1:46864
+            RedisClient::CannotConnectError: Connection refused - connect(2) for 127.0.0.1:46864'
+          MSG
+
           expect {
             redlock.lock(resource_key, ttl)
-          }.to raise_error(Redlock::LockAcquisitionError)
+          }.to raise_error do |error|
+            expect(error).to be_a(Redlock::LockAcquisitionError)
+            expect(error.message).to eq(expected_msg.chomp)
+            expect(error.errors.size).to eq(2)
+          end
         end
       end