It’s all about the public blockchain which offers us the real power to change the way our technology drives our future. But testing blockchain applications is quite different from testing traditional applications. Also all the normal heuristics, we have to take into account things like how our app will behave when events outside our control affect the network, whether people are able to front-run our transactions, and even whether our transactions are going to become too expensive to justify the existence of our application.
What is blockchain testing?
The blockchain is a digitized, decentralized, openly shared public ledger that details every value and is designed to record transactions and track assets in a business network, transfer transaction. Blockchain relies on a peer-to-peer computer network comprised of its users’ machines. Its peer-to-peer architecture combined with its immutability, transparency, and disintermediation of “middlemen” make it an ideal platform for the sale and transfer of any value-based asset. To ensure trust among the users, Blockchain components must be intact with each other.
Testing the Blockchain
To promote trust, testers need to ensure that all blockchain components work correctly and that any related applications delivered to the blockchain fabric interact in a trusted fashion. Testers should follow a best practice-based suite of testing approaches that include several paths: Shift Left, API, Functional, and Performance Testing here are:
- Shift Left Testing
The need for software quality in every step of the value transfer process presents a strong argument for shift left testing. More blockchain project teams are employing Agile and DevOps practices to their development and testing efforts. By shifting testing to the left, teams can perform various tests early, and reuse those tests continuously. Providing early, iterative quality feedback during development decreases the number of defects found later in the lifecycle, where the impact on the business can be severe.
- API Testing
Depending on the application, API testing needs to address the interaction of applications into and out of the blockchain ecosystem. Because a blockchain can emit events, external calls or events from external systems can trigger blockchain activity. Consider a transaction submitted to an API. The transaction must be validated against specific rules to generate an update order which the blockchain then distributes. The API then receives a confirmation that the blockchain has been updated. Testers must validate the interaction of applications into and out of the blockchain ecosystem at every process step to validate that API requests and responses are formatted and handled correctly.
- Functional Testing
As blockchain evolves into new application areas, functional testing of essential blockchain components, as well as the holistic ecosystem, is vital. Functional testing evaluates use-case scenarios and related business processes, such as the behavior of smart contracts.
- Performance Testing
Performance testing in Blockchain includes identifying performance bottlenecks, defining the performance metrics, and accessing if the application is ready for production.
At article press time, blockchain performance is hampered by an inability to scale – as an example; blockchain is currently unable to process the volumes of transactions necessary to replace the proprietary payment processing systems of financial service organizations. Therefore, as blockchain evolves, the participant-user experience will focus as much on trust as transaction processing speed. The performance test should be applied to blockchain based on the perspective of a client app end user, responses required from smart contracts, and system interfaces.
How Do You Test Blockchain Applications?
We agree that it’s really not much different from any other application you would test. The same logic and critical thinking you already use for testing non-blockchain projects still apply.
Of course, the individuals working on blockchain applications need to possess amazing mathematical and cryptographic skills, but when it comes down to it most of the work that’s being done is just normal development work with normal testing criteria.
Many of the testing techniques you already know, like testing at the boundary, performance testing, compliance and especially security testing, apply to the blockchain. Sometimes it’s just a matter of getting familiar with some of the common blockchain testing tools that are already out there:
- Ethereum Tester
- Ganache (formally Testrpc)
- Hyperledger Composer
- Exonumia Testkit
- Embark Framework
- Corda Testing Tools
Blockchain components that testers want to consider include:
- Block size: Block size will likely vary based on the application of the blockchain. Hence, the payloads in the block will vary in size as well. For many blockchains, less than 100 bytes of each block is designated for non-payload. As of this writing, there is currently a fixed maximum limit of 1MB per block for Bitcoin. The point is, testers need to evaluate how changing block size impacts behavior. What happens when the amount of new data going into a block exceeds the maximum block size for that blockchain application? How will the block be handled? Remember that multiple transactions can be assigned to one block.
- Chain size: The expectation of blockchain is that it provides a permanent and complete record of every value transfer transacted on the chain, so theoretically, the size of the chain is unlimited.
- Data transmission: Due to the peer-to-peer architecture of blockchain, it’s essential to validate that the encrypted and decrypted data transmission process works flawlessly. A critical test scenario is to make sure that no data is lost.
- Adding a block: Whenever a transaction is authenticated, testers need to validate that a new block is attached to the chain. Remember that the chain is immutable. It’s important that whenever a new block is added that it be added correctly because it can never be changed.
The blockchain is an emerging technology that offers applications far beyond that of secure payments. As it evolves into a platform for digital transformation, blockchain offers a disruptive and cost-saving alternative to the current centralized transaction and record-keeping mechanisms that exist in global organizations today. As with any new technology, the success and adoption of blockchain are predicated upon its scalability. With blockchain, however, trust in consensus is fundamental to the integrity and consistency of every blockchain transaction. Continuous testing is an essential pillar for establishing trust and includes the testing of APIs as well as through functional and performance testing.