Blockchain Testing Guide. Challenges in Blockchain Testing

Blockchain was invented in the pursuit to provide immensely secure and efficient data management and storage. This technology is mostly associated with cryptocurrencies, but in reality, it has turned out that it can be useful across the most diverse domains. Finance, banking, healthcare, real estate, automotive, government, manufacturing, media, and insurance are just a few to mention. Consequently, the number of blockchain-based apps is rapidly growing. Along with this, the testing community has faced the necessity to test this kind of software. How can it be performed properly? What is worth particular attention?

What is Blockchain?

First of all, let’s dive deeper into what blockchain technology is and what its key properties are.

While blockchain technology was invented in 2008, these days it is still a hot subject. So what technology does lie behind it? Blockchain is Greek to most people. So let’s figure out together how it works.

Blockchain is usually defined as a distributed and decentralized database or digital ledger. What makes it different from a common database is its structure. In a blockchain, digital data is collected and stored in bulks that are called blocks and have a particular storage capacity. When new data is validated, this block is closed and linked to a previously added block by means of cryptography. In such a way a chain of multiple blocks is built.

Every block in a chain includes record or transaction data, a timestamp, own hash, a hash of a preceding block, and a nonce. A timestamp is the exact time of block creation. A hash serves as a digital footprint. In fact, this is digital information itself turned by a mathematical function into an alphanumeric string. As for nonce or ‘number used only once’, this is a 32 bits encrypted number that a miner must solve for new block verification and close. It is worth noting that this is a math problem of immense complexity to find a nonce generating an accepted hash.

A miner who first finds the right nonce reaps a reward encouraging them to keep on validating transactions.

Once a block is linked to a chain, its content cannot be deleted or modified. This is due to the fact that each block includes a hash of a proceeded block. In case a block is modified in any way, a hash gets changed too. Consequently, data tampering is detected immediately.

Theoretically, rollback is possible, but this would be incredibly difficult because for this the vast majority of the nodes (participants) should reach a corresponding consensus.

To sum it up, blockchain is immutable and transparent due to decentralization and cryptographic hashing.

Blockchain Types

Blockchain is going to be commonly used in the nearest future. Even today, there are a number of various blockchain platforms. Ethereum, IBM Blockchain, Tron, Stellar, and Corda are just a few to mention. Still, we’d like to draw your attention to the fact that there are three main categories of blockchain - it can be private, public, and hybrid.

A private blockchain suggests compulsory approval of each node before its joining. As long as in blockchains of this type all nodes are supposed to be reliable, their security layers are not so solid.

A public blockchain, on the contrary, lets anyone become a member of a network. Blockchains of this type must have solid cryptography and a consensus system to ensure rocket-solid security.

A hybrid blockchain is a combo of the above-described blockchain types. For example, enterprises can establish a private blockchain platform along with a public one. In this case, they restrict access to particular information in the blockchain while keeping the rest of it open.

The Main Properties of Blockchain

Blockchain has proved itself as being incredibly reliable and important. This technology is gaining popularity due to a range of its unique features. So, we cannot help but present the key characteristics of blockchain that are worth your attention:

Importance of Blockchain Testing

The advent of smart contracts has given an opportunity for the simulation of varied business processes. Consequently, now a great number of blockchain-based applications are created.

As with any other apps, blockchain-based apps also require comprehensive testing to ensure their smooth and secure work. By testing your blockchain app, not only do you please its users but also prevent catastrophe.

As mentioned before, immutability is one of the main blockchain properties, so any mistake cannot be eliminated. For instance, if there is a bug in a smart contract, deployment of a new correct smart contract is the only means to fix the consequences of the bug. Security flaws resulting in a hacker attack may require a global network change.

Therefore, in this case, testing is indeed a must.

Tests Сompulsory for Blockchain-Based Applications

Numerous tests must be executed in order to assure the superb quality of a blockchain-based app:

If an already available blockchain platform has been used, usually there is no need to test its components (nodes, block size, chain size, etc.) similarly to databases or messaging libs. However, it is still compulsory to carefully check smart contracts.

A smart contract is a program code inbuilt directly into the blockchain. It is executed automatically whenever the predetermined terms and conditions are fulfilled.

Once deployed smart contract stays on a blockchain forever, and it is paramount to be sure that it does not contain bugs. Consequently, smart contracts are carefully checked to make sure that business logic combinations along with corresponding triggers result in the proper execution of particular transactions.

Smart contract testing suggests a scrupulous investigation of its source code along with the execution of unit, integration, and system testing.

As a rule, smart contracts are checked through automated testing, but manual testing can be applied as well. Of course, the latter is rather time-incentive and requires specific skills because all lines of the code must be checked and evaluated but in its course, serious vulnerabilities can be identified that autotests may have not detected.

Challenges of Blockchain App Testing

There are some challenges related to blockchain app testing. So the main of them are presented below.

Blockchain Testing Tools

Here are three commonly used automation testing solutions for blockchain-based apps:

Takeaway

Blockchain is a rather sophisticated technology. However, apps based on blockchain provide numerous benefits. Security, traceability, transparency, and the ability to get rid of intermediacy are the most noteworthy ones.

Although blockchain-based apps have come with certain difficulties for the testing community, their testing is still compulsory. As blockchain adoption is constantly gaining momentum, QA specialists need to get new knowledge and master new skills.