Testing Blockchain Applications

Hello all, today I am going to post about a topic that I am a huge enthusiast about: Blockchain !

Nowadays data is one of the most valuable product that you can own, and as we are surrounded by fake data coming from thousands of different places, it is hard to know what is trustworthy or not.

What is Blockchain ?

It is basically the second phase of the internet. The Internet democratized the exchange of information, blockchain promises to democratize the exchange of real value. It was created in 2008 by Satashi Nakamoto, which the identity is still unknown.

An example of how blockchain can be used is when you want to make a transaction of £10 from a X to Y. Nowadays what happens is this transaction goes through a third-party app or payment processing system. Then, X’s bank will need to check the details of Y’s bank and once this is done the transfer of the amount will initiate with a certain amount of deductions, of course. In the end both banks will record the transaction deducting the transaction fee, meaning Y will receive something like £9.95. Even though this process is quite secure and has many redundancies in place to make sure that it stays secure and accurate, there are some basic fundamental issues with this process:

  • Delay in processing (using this middle agent and all the bureaucracy)
  • Dependency on a single intermediary whose effectiveness is never 100 percent (dependency on a national state)
  • In case of any gap in the transaction, no one takes the responsibility and people keep on blaming each other (not concrete proof to check the transaction)

Blockchain is a system where you no longer have to worry about these problems, you just need to perform a transaction and there is a chain of people who are able to validate your transactions every second. This mechanism is called as Proof of block and this is done based on the public key provided for the encrypted data, and it is done by all listeners in the peer-to-peer network. They are real people/identities, not bots. Since there is not a single transaction validating authority (banks, national state) who are centralising the transaction service, the process is effectively decentralized, public and transparent for everybody to see.

Once a specified number of people validates the transaction, the transaction details are stored in the form of a block and that block is added to the existing blockchain. Once the blocks are validated, nobody can change them, just add another one on top, they are immutable. These blocks have a specific hash associated with every block. These hashes are like fingerprints and are unique to every block. Every person that is validating the transaction process is called a miner. The more miners, the better efficiency of the transaction.

A block contains data, a hash, and the hash of the previous block. Since it contains a hash of a previous block, all the blocks contain data for the previous blocks and it becomes almost impossible for a blockchain to be corrupt.

What types of tests can I perform in a Blockchain app ?

  • API Testing: In API testing, we ensure that the interaction between applications in the blockchain ecosystem is as expected
  • Block/Peer/Node Testing: All the blocks on the Network should be tested individually to ensure proper cooperation. All diverse nodes on the Network must be tested independently to ensure smooth cooperation. Do the nodes in the network sync with other validating peers? Is the integrity of the network and shared ledger maintained throughout the testing?
  • Functional Testing: In Functional Testing, we evaluate the work of various functional parts of the Blockchain (e.g., smart contracts).
  • Performance Testing: Details like network latency based on block size, network size, expected transaction size, and how long a query takes to return the output with the specialized authentication protocol
  • Security Testing: Here, we ensure that the application is not vulnerable to attacks and the systems can protect the data and are capable of handling malicious attacks, etc.
  • Integration Testing: In Integration testing, we ensure that all the components of the application are integrated properly and performing the actions appropriately
  • Smart Contract Testing: Smart Contract testing is about performing detailed functional testing of business logic and process. It refers to the set of software constructs that automatically execute transactions when predefined conditions and business logic are met. Testing smart contracts involve simulation of all possible expected and unexpected variables for every contract and the triggers that execute transactions.

Benefits of Blockchain Apps

  • Decentralized System: No need to have a middle agent for the transactions. Beneficial in various industries like finance, real estate etc.
  • Better Security: As it uses multiple nodes to complete and authenticate transactions, you don’t rely only on a transaction system that is controlled by a centralized group of identities.
  • Authenticity: Allows the unique algorithm to process data, like a fingerprint.
  • Increased Capacity: Increases the capacity of the entire Network as it is completely decentralized and real people can verify the blockchain.

Challenges in Blockchain Testing

  • Understanding the Technology: Blockchain is a new technology and understanding it is very important in order to test it. Where does regulatory compliance overlap with quality? How do you fix a defect that has been deployed as part of an immutable smart contract? How do you predict transaction fees and determine the correct behaviour of your application if transaction fees and network volume increase unexpectedly?
  • Lack of Blockchain Testing Tools: Blockchain-based applications testing is all about tools. Selecting the right tool as per application is one of the important decisions.
  • Defining Test Strategy: Designing Test Strategy for Blockchain application is quite complex exactly because you need to have a good understanding and in-depth knowledge of the technology.
  • Block and Chain Size: Testing for block size and chain size is quite important as the application may fail without proper validation of block size and chain size and creating a false-positive verification.
  • Integration Testing: Should be done properly and frequently to test that all the components are properly integrated.
  • Performance and Load: You need to perform load testing to give better insight into how the Blockchain application performs in the real world, check if it is scalable and what are the limits. Check the example that was done to Ethereum and the Cryptokitties.
  • Security: Securing the data should be the most important thing in a Blockchain Application, to be honest, in any application. Even bitcoin is not bug free !

What do you need to consider when testing a Blockchain Application?

Here it goes an example with Bitcoin transaction tests:

  1. Block Size: The maximum fixed limit of a block is 1 megabyte. After the introduction of Bitcoin, the average size of a block for the first 18 months came out to be under 30 KB. But in December 2017, it hovered around 1 MB. What if the size of a block exceeds beyond 1 MB?
  2. Chain Size: There is no limit on the size of the chain. So, it is fun to test it for its function and performance. For example, the Bitcoin chain’s size keeps on increasing day by day.
  3. Load: With so many people on the blockchain, the load becomes a major parameter to test in a blockchain. Bitcoin currently has a maximum throughput of 3.3 – 7 transactions per second, but what if the transaction/second increases as in the case of Visa(2000), Paypal(193), etc? The load remains a major problem with blockchain because performance drops when the load increases.
  4. Security: Since there are many miners involved with a transaction, ensuring security is a little complex. Well, there is a multi-layered security system in a blockchain. If one of the layers has been hacked, the instantaneous transactions cannot be stopped. It is, therefore, to be tested that one security layer doesn’t affect the other.
  5. Transmission of data: Encrypted and decrypted data is transferred from computer to computer, so it is necessary to test if the transmission process is working flawlessly. Is the data being sent received on the other end, or is there a loss in between?
  6. Addition of block: Every new block is added to the chain once the transaction’s validity is authenticated. So, it must be tested that there should not be any leak in the block addition system and the block must be added after authentication.
  7. Cryptographical data: Cryptography is the backbone of blockchain technology. Therefore, it is necessary to make sure that the data is properly encrypted and decrypted.

Blockchain Testing Tools

  1. Ethereum Tester: It is an open-source testing library available as a Github repo. Its setup is pretty easy with a manageable API support for various Testing requirements.
  2. BitcoinJ: It is a Java-based framework built for Bitcoin-based apps that enables you to interact with the real BTC network and various testing activities. In order to use it, you don’t have to download the standard BTC Core files from Bitcoin.com. You can even approach a user forum in case you need clarification or are facing hiccups in the testing process. It is an open network available for assistance.
  3. Populus: This framework has the testing functionality of Ethereum embedded in the form of a set of features for test contract deployment. It’s developed around the py.test framework. Hence, it is relatively easy to implement.
  4. Truffle: It’s a commonly referred name for Ethereum developers, which brings in good testing features, such as automated contract testing. The framework holds capabilities beyond just testing functionality within the Blockchain application.
  5. Embark: It is a testing framework that focuses on developing decentralized applications (dApps) that run on various systems or nodes. It has integrations with Ethereum blockchain, IPFS, and a decentralized communication platforms such as Whisper and Orbit.

Future of Blockchain

Even though Blockchain is often discussed in financial services and cryptocurrencies, this technology offers a broader range of potential applications. The use case of Blockchain technology is picking up pace in various industries and segments. A World Economic Forum report predicts that by 2025, 10% of Global Gross Domestic Product (GDP) is stored on Blockchains or Blockchain-based technology.

Free courses

Resources:

https://www.etestware.com/why-companies-need-blockchain-testing/
https://www.guru99.com/blockchain-testing.html
https://www.cigniti.com/blog/5-popular-tools-for-testing-blockchain-applications/
https://www.testingxperts.com/services/blockchain-application-testing/gb-en
https://blog.b9lab.com/testing-blockchain-applications-not-just-for-testers-bb5932981df4
https://dzone.com/articles/all-you-need-to-know-about-blockchain-testing
https://blogs.iadb.org/caribbean-dev-trends/en/blockchain-technology-explained-and-what-it-could-mean-for-the-caribbean/
https://www.youtube.com/c/exodusmovement/videos

Blockchain Testing Tools

If you are wondering what Blockchain is, I will give you a quick introduction. Blockchain is a data structure that is distributed at once in many different places and as you can’t ever delete from it, it is extremely difficult to make amendments. This makes the record more secure and more trustworthy.

So, what are the kinds of test that you can perform ? You can use the traditional testing, since it is just normal development work with normal testing criteria. So, boundary value analysis, decision tables, test driven development and behavior driven development techniques.

There is also a set of questions that can help you to build your test scenarios, for example:

  • How does it handles valid and invalid inputs?
  • How does it cope with a wide range of input data?
  • How does it handle missing state, or existing state?
  • How does it handle error cases?
  • How does it handle security and access control?

You don’t need to test the Blockchain because the algorithms are well-established, because it is a distributed system, but the transactions still require some kind of validation. For example, you may need to check if your transaction is valid before it can be approved. There are approval authorities for different blockchains, and they must test the integrity of the transactions.

 

What is Smart Contract ?

Smart Contract is an API and defines the rules for transactions in a Blockchain network. A Smart Contract is a set of rules in the form of programmable constructs that are capable of automatically enforcing themselves when pre-defined conditions are met.

It has public functions which might be called by anyone registered on the Blockchain network. However, unlike a traditional API, a Smart Contract cannot call external web APIs.

 

What do you need to know to test Ethereum Smart Contracts ?

Test automation requires that the platform being tested must have hooks so that external automated scripts can instruct the platform, observe the outcome, and verify that the outcome is what is expected. Legacy platforms in banking often do not have these hooks, and that makes automation much more difficult. When you compare smart contracts to older software used in banks, you can automate testing much earlier and much faster.

 

I will show some of the tools that you can use to perform tests on Blockchain applications:

 

Ethereum Tester

This github has a project for you to test Ethereum Blockchain Applications. You will need to clone Eth-Tester. The Eth-tester library strictly enforces some input formats and types.

 

Truffle

Truffle is one of the most popular Ethereum development frameworks and has testing functionality, it is a scaffolding framework for smart contracts used by UI builders. You have the ability to write automated tests for your contracts in both JavaScript and Solidity and get your contracts developed quickly.

Ganache

Ganache is the most-used library for testing Ethereum contracts locally. It mocks a blockchain that gives you access to accounts you can run tests, execute commands, etc.

 

Populus

By default tests run against an in-memory ethereum blockchain and as you can see here Populus supports writing contracts that are specifically for testing.

 

Manticore

Manticore is a symbolic execution tool for analysis of binaries and smart contracts. It is supported on Linux and requires Python 2.7. Ubuntu 16.04 is strongly recommended. It has a Python programming interface which can be used to implement custom analyses. You can see more about here on the wiki.

 

Hyperledger Composer

Hyperledger Composer supports three types of testing: interactive testing, automated unit testing and automated system testing. It’s a framework for rapidly building Blockchain business networks on top of a Blockchain platform, such as Hyperledger Fabric.

This framework allows you to automatically deploy the business network definition, and then interact with it by submitting queries and transactions in order to test how that business network really behaves.

 

Corda Testing Tools

Corda is a blockchain-inspired, open-source distributed ledger platform. There are several distinct test suites each with a different purpose: Unit tests, Integration tests, Smoke tests, Load tests and other. These tests are mostly written with JUnit and can run via Gradle.

 

BitcoinJ

This tool BitcoinJ allows you to interact with Bitcoin connecting directly to the bitcoin network. So, you can simulate send and receive transactions in real time, also you don’t need to have a local copy of the Bitcoin Core.

You can follow this guide to get start with this tool.

 

Resources:

https://www.joecolantonio.com/2018/02/01/blockchain-testing-tools/

https://joecolantonio.com/testtalks/175-blockchain-application-testing-rhian-lewis/

http://searchsoftwarequality.techtarget.com/answer/Heres-everything-you-need-to-know-about-testing-blockchain

https://www.capgemini.com/2017/01/testing-of-smart-contracts-in-the-blockchain-world/

http://www.bcs.org/content/conWebDoc/56020

https://medium.com/@mrsimonstone/test-your-blockchain-business-network-using-hyperledger-composer-c8e8f112da08