This document discusses testing Ethereum smart contracts. It provides an overview of Ethereum as a distributed public network running the Ethereum Virtual Machine. It describes how to set up a testing environment using Geth and Truffle, including developing smart contracts, running unit and integration tests. It also discusses non-functional testing like node, performance, and security testing.

1. GLOBAL SOFTWARE CONSULTANCY
TESTING ETHEREUM SMART
CONTRACTS
By
Preet G S Anand and Himanshu Pandey
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VodQA Pune 2019

2. 2©ThoughtWorks 2019 Commercial in Confidence
AGENDA
BRIEF OVERVIEW OF
ETHEREUM
DAPP ARCHITECTURE AND
TESTING COMPONENTS
TESTING IN BLOCKCHAIN
PARADIGM

3. BRIEF OVERVIEW OF ETHEREUM
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Decentralized platform that runs smart contracts

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WHAT IS DLT?
● Distributed Ledger Technology
● Distribute the ledger across all nodes
● Every node has complete copy of the
ledger, and all ledgers are always in sync

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WHAT IS ETHEREUM ?
DISTRIBUTED PUBLIC
NETWORK
CONSENSUS ETHEREUM VIRTUAL
MACHINE

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DISTRIBUTED PUBLIC NETWORK
● Ethereum is a peer to peer network, somewhat like a mesh topology
● Any new node can be added to this network
● Any machine which is part of ethereum network is a node
● There are three types of ethereum nodes:
○ Full node
○ Lightweight node
○ Miner node

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CONSENSUS
● Achieve agreement on a single data value in blockchain
● Involves reward for nodes which participate in consensus resolution
● Types :
○ Proof of Work (POW)
○ Proof of Stake (POS)
○ Proof of Authority (POA)

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ETHEREUM VIRTUAL MACHINE
● Ethereum is a programmable blockchain
● EVM is “Turing Complete”
● EVM is something which differentiates Ethereum with Blockchain
● Each and every node of the network runs the EVM and executes the same
instructions

9. DAPP ARCHITECTURE AND TESTING
COMPONENTS
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10. DAPP ARCHITECTURE
10
HTML / JS / CSS
Block
EVM
BLOCKCHAIN FRONT END
BROWSER
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API
DB
WEB3 API
RPC
Smart
Contracts

11. HOW IS IT DIFFERENT FROM A WEB APP
11
PARTY A
PARTY B
PARTY C
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12. Different parts of Web3 API
● Node / Java / Python API
○ Uses Web3 library
○ Talks to blockchain via RPC calls
○ Provides wrappers over smart
contracts
● Smart Contracts
● Database
HOW DOES THE API LAYER LOOK LIKE
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API
DB
Smart
Contracts

13. WHAT IS A SMART CONTRACT
● Smart contracts is a misnomer.
● They :
○ Store rules
○ Verifies rules
○ Self execute rules
● Removes need of a middle man as they are self
executing, ex: Vending machines
● Help in exchanging money, property, goods in a
transparent, direct and trusted way.
● They are responsible for creating blocks in
blockchain.
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14. SETTING UP A TEST ENVIRONMENT
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15. ● In order to communicate with the blockchain, we must use a blockchain client
● Geth is an ethereum client and is written in Go
● Enable you to connect with blockchain over RPC endpoint
● Provides API for account management,transaction management, peer
management, debugging
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GETH

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● Development environment
● Testing framework
● Asset pipeline for blockchains using the Ethereum Virtual Machine
TRUFFLE

17. ● Install truffle
npm i -g truffle
● Initialise project
truffle init
TRUFFLE SETUP
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18. TESTING IN BLOCKCHAIN PARADIGM
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19. UNIT TESTS
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● Written in solidity (.sol) files
● Direct access to your deployed contracts
● Ability to import any contract dependency

20. INTEGRATION TESTS
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● Written in javascript (.js) files
● Uses the Mocha testing framework and Chai
for assertions

21. NON FUNCTIONAL TESTING
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22. NODE TESTING
● Network Handshaking
● Consensus Handshaking
● Chain Syncing
● Tools : eth-tester
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23. PERFORMANCE TESTING
● Network Latency
● Transaction Per Second (TPS)
● Block/Transaction Size
● Gas used per transaction
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24. SECURITY TESTING
24
● Access and Authentication
● Network Permissioning
● Wallet Signature Method
● Private Keys
● Smart Contract Owner
Verification
● Tools :
a. Solium
b. Solhint
c. openzeppelin-solidity
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25. THANKYOU
25
Preet G S Anand
APPLICATION DEVELOPER
preetgsa@thoughtworks.com | thoughtworks.com
©ThoughtWorks 2019 Commercial in Confidence
HIMANSHU PANDEY
APPLICATION DEVELOPER
phiman@thoughtworks.com | thoughtworks.com