At present, Blockchain shares the podium among the dominant technologies in the world. Though blockchain is not new, it gained traction in 2011 with the introduction of the first blockchain explorer, followed by a cryptocurrency wallet that accounted for 28% of bitcoin transactions between 2012 and 2020. Today, decentralization is closely related to blockchain and cryptocurrencies.
With the numerous advantages of decentralization, most notably the elimination of the requirement for a central authority to control the rules, an increasing number of individuals are turning to blockchain for investments, money borrowing and lending, and other related activities. Blockchain preserves the privacy of your data and allows you to determine who has access to how much of your personal information. It also assures that the data you get on the platforms has been pre-verified by authorized agents.
Understanding Blockchain Structure
The whole system of blockchain is based on cryptography, which is a mechanism that employs digital signatures to grant access to only those who have been granted permission to VIEW your data. Because of its tight integration and chained cryptography, other users around the world can only view your data and cannot make any changes. To make things easier, let’s first look at the construction of a blockchain.
Now each block that you see above has three elements that are the data, the hash, and the hash from the previous block. Refer to the image below:
As a result, the code for each block is a combination of the current block’s hash, the prior block’s hash, and a data code. This assures that if one block is tempered or even attempted to be tempered, all subsequent blocks in the chain become invalid instantly. However, this does not rule out the possibility of future updates to blockchain data. The only difference would be that anytime a user desires to update any changes, their data will be appended to the end of the chain, similar to the classic ledger entry method we learned in school.
The potential of blockchain-based applications is huge and that’s where decentralized applications come into the picture.
Introduction to Decentralised Applications
Decentralized applications or dApps are digital applications or programs that function on a blockchain or peer-to-peer network of computer systems. These applications are never controlled by a single authority and use the power of blockchain and smart contracts to enforce the agreement between the parties.
It’s this feature of these applications that make them secure, thereby distributing the ownership to multiple systems. So, whenever someone joins this network of applications, he/she gets a full copy of the blockchain. Any change or input introduced by any parties, once approved is also shared by all the systems that ensure everyone is updated with real-time data and helps verify that everything is still in order.
Another very effective way of securing and verifying your information/ data online is through smart contracts. Moving forward, let’s have a closer look at smart contracts.
What are Smart Contracts?
The term smart contracts were first introduced by Nick Szabo, in 1997. Exactly like any other contract, smart contracts are legally binding documents but purely digital in nature. It’s basically a piece of code that creates a business logic and is executed on the blockchain system in a decentralized manner. It’s a tiny computer program that is fed in a blockchain and its main function is to store, facilitate, and self-execute rules. A programmer is supposed to code a contract with certain rules that specify if the ‘A’ situation is achieved, then ‘B’ will happen.
These digital contracts help gain autonomy and independence from third party structures that ensure the reliability, security, accuracy, and profitability of your data
The prime examples of smart contracts and dApps include games, DEX (Decentralized Exchange), NFT marketplaces, gambling, blockchain-powered social networks, DeFi (Decentralized Finance), etc.
What is the Need to Test a Smart Contract?
So, there are two basic features of blockchain applications, immutable and distributed. An immutable application means that once a smart contract is created, it can never be altered again and no one can go behind your back and temper the code of your contract. Any changes, if needed, need to be added towards the end of the smart contract. Distributed, on the other hand, means that the output of your contract has to be validated and accepted by everyone to become a part of the larger data system. This ensures no single person can have a monopoly over decisions and force a kind of action without others approving of the change. This makes tampering with a smart contract almost impossible, making it extremely reliable and secure.
Now, because of the same immutable feature of a smart contract, the minutest logic error in the application can cause serious damage to the application and data. When it comes to financial applications, individual wallets can be blocked and users may not be able to have access to the money they invested because of smart contract vulnerabilities. Is there a way to avoid these circumstances? The answer is testing!
There are well-established QA consulting companies that adopt agile testing methodologies and provide end-to-end blockchain testing solutions for enterprises globally to help you ensure the proper safety of your application.
More on these companies later. Let’s move forward to how to go about the testing of a smart contract.
Initiate Smart Contract Testing
Proper testing is a must before using a contract in different situations to ensure its working properly. Below mentioned are some aspects of blockchain testing that all professional QA testing teams should take into consideration while going about the testing of a blockchain-based application.
- Digital signatures
- Fixing contract code and related changes
- Contract Subject
- Necessary tools for contract execution
- Terms of execution in contract code
- Recurring and selective events
- Possible scenarios of errors and messages
- Changes in the contract status and balance
Various Aspects of Testing a Smart Contract
The first step is to simulate, analyze and do a close prediction of all possible scenarios in the logic of each contract.
Start by answering the below-mentioned questions to make the process easier
- Which events should be initiated?
- What techniques should be used?
- How the balance and status of your contract are moving?
- How and to whom funds transfer should happen?
- What error to cause?
- Who is the author of the message?
- What is the current time used?
Let’s take the example of developing a smart contract using Ethereum. While using Ethereum, it is important to set proper guidelines on the usage of the Gas Value — that’s the cost of a smart contract that Ethereum has set for its launch.
It’s all based on the security of an agreement. A situation where certain data is stuck in a contract is very similar to a situation when it’s stolen. This means a similar scenario can be used to test a blockchain-based application against data tempering as well.
Other than this, the general principle of testing any blockchain-based application is very similar to the way other applications are tested.
To ensure how accurate and failure-proof your application’s code is, your QA engineer is supposed to check each and every aspect of your app, including the date, parties of the contract, execution time, hash validation, and fund transfer processes.
Typically, the following tests are executed to achieve the above results.
1. Unit Testing
Conducted to test the individual features of a smart contract
2. Regression Testing
Executed after the modification of a smart contract. The idea is to re-run unit tests after every little modification in the code to ensure the smart contract remains error-free and operates smoothly
3. Integration Testing
Tests all other smart contract modules connected with other systems and the main application to ensure they are well integrated
4. Compliance Testing
This is one of the most important aspects of smart contract testing because it helps verify that your smart contract meets all necessary regulatory requirements set by the local government or other governing bodies
The choice to opt for complete manual testing or a mixture of automated and manual testing depends on the testing strategy set by your software testing company. Manual testing ensures every aspect of your application is thoroughly tested whereas automated testing ensures full coverage given the size of the application data.
There are various characteristics of functional, security, and load testing as well that can help improve the quality of your blockchain-based applications.
A good software testing partner will closely work with your development team to foresee all possible contract outcomes and ensure no loopholes are left before the final release.