New, cutting-edge technologies are entering the marketplace at an unprecedented speed. The headline-maker on the block happens to be Blockchain, a technology that grabbed eyeballs as one of Bitcoin’s core components. Today, Blockchain is more than just Bitcoin. The blockchain is emerging as the next tech disruptor. According to a survey by the World Economic Forum, 10% of the global GDP will be relying on Blockchain-based technology by 2027.

So, what is Blockchain Technology?

The brainchild of a person or a group of people using the pseudonym Satoshi Nakamoto, Blockchain is, according to Don & Alex Tapscott, authors Blockchain Revolution (2016), an incorruptible digital ledger of economic transactions that can be programmed to record not just financial transactions but virtually everything of value”. The blockchain is essentially a distributed ledger, a continuously growing record list called blocks that are linked and secured using cryptography. This distributed ledger or Blockchain consists of an encrypted digital filing system that creates tamper-proof records in real-time. In other words, Blockchain can be looked upon as an open infrastructure capable of storing several different kinds of assets.

Blockchain and Testing

The blockchain is unique because it removes the need for a middleman to physically oversee transparent actions in real time while at the same time preventing fraud. Supply chain, healthcare, energy, event-ticketing, sales etc. are industries that present themselves to this technology very well. The algorithms used in Blockchain are well-established. Given that it is a distributed system, Blockchain blocks do not have a master copy and are stored in different locations. So, when it comes to testing in Blockchain, given that the algorithms used are sound do we really need to test?
A block, when added to a Blockchain, remains there forever. Any changes to one block will render the following blocks invalid. So, a single change in the Blockchain means that all the subsequent blocks have to be changed simultaneously and right away. Since this cannot be done at a later date, testing of the Blockchain becomes quite complex.

Testing Blockchain-based applications are challenging also because there is a significant change in the technology itself. For sure, Blockchain applications will demand the standard testing and validations such as functional testing, performance testing, integration testing, and security testing. But, that apart, testing teams will also need some specialized testing capabilities.

Standard functional and Non-functional testing

• Functional Testing: Blockchain technology is finding new applications faster than before. Functional testing of the basic components, the system, and its workings is essential. Testing here is conducted to assess the effectiveness of use-case scenarios and the specific business processes involved.
• Integration Testing:
  Integration testing is important for Blockchain since deployment could be across several systems and environments. Given this, it becomes essential to ensure that the interfaces between the components, the integrations, and the different parts of the system are functioning cohesively. This is essential to ensure performance consistency.
• Security Testing:Security testing has to be aggressive for Blockchain applications. The aim is to identify if the application is vulnerable to attacks, assess if the authorization systems are robust, identify if the system protects the data and has the capability to ward off malicious attacks etc. Along with this, it is imperative to test integrity, authentication, confidentiality, and non- repudiation during security testing.
• Performance Testing:Blockchain applications are built for speed. This makes performance testing even more important. The performance of an application and the latency vary with networks as well as transaction size. Performance testing in Blockchain includes identifying performance bottlenecks, defining the metrics for tuning the system, and assessing if the application is ready for production.

Specialized Testing

• Smart Contract Testing:Smart Contract testing is a specialized testing. Smart contracts lie at the core of the Blockchain validation process. Testing of smart contracts calls for simulating all possible expected and unexpected conditions for all possible contract. Testing looks at business logic combinations and appropriate execution of all the transactions in the context of a dynamically changing and expanding the network.
• Peer/node Testing:The power of the Blockchain lies in the shared ledger being exactly the same at each and every node with the same set of and sequence of transactions. This makes it essential to achieve a consensus across all nodes on the order in which the transactions are added to the network. Peer/Node testing for the consistency of transactions is needed. This calls for the testing of the consensus protocol to determine that all the transactions get stored in the proper sequence. This would have to be the case under normal conditions and also under conditions when nodes fail simultaneously or when they do not participate in the network for some time. These tests help ensure that the nodes in the network sync with other validating peers and the integrity of the network and shared ledger are maintained throughout.

Along with all this, testing for block size, chain size, transmission of data, and testing of cryptographical data are also essential to Blockchain applications. Given the sheer number of nodes and the various combinations and transactions that need to be validated, test automation may well prove critical to the success of Blockchain applications.

Conclusion:

The blockchain is an emerging technology, but one that has made everyone sit up and take notice. And like any new technology, how well and how comprehensively we can test will play a key role in its success and adoption and in how much we are able to participate in that success. What does your Blockchain testing strategy look like?