VodQA(Bangalore) 2018 Speaker Name: Srinivasan Sekar, Lipika Dugar Presented in : VodQA(Bangalore) 2018

1. Testing Blockchain Application
Lipika Dugar
@lipikadugar
lipikad@thoughtworks.com
Srinivasan Sekar
srinivasantarget
sekars@thoughtworks.com
Blockchain

2. Agenda
➔ Introduction to Blockchain
➔ Significance of Blockchain Technology
➔ How does a Blockchain work
➔ When do we need it
➔ Types of Blockchain
➔ Blockchain in Real World Problems
➔ Smart Contracts
➔ Sample Application with Blockchain
➔ Test Strategy for Blockchain Application
➔ Blockchain Testing Tools in Market
➔ Contract Testing and Functional Testing

3. Lets “Understand the theory behind the working of Blockchain, when to
use it and how can we test Blockchain Applications”

5. What is a Blockchain

6. Blockchain History
1991
2009
Document Timestamp

7. Blockchain Use cases
Financial Institutions
❏ International Payments
❏ Capital Markets
❏ Trade Finance
❏ Insurance
❏ Peer-to-peer transactions
❏ Regulatory compliance &
audit
❏ Anti-money laundering &
KYC
Corporates
❏ Healthcare
❏ Real Estate
❏ Media
❏ Energy
❏ Supply chain
Management
Governments
❏ Record Managements
❏ Identity Management
❏ Voting
❏ Taxes
❏ Govt & non-profit
transparency
❏ Legislation, compliance
& regulatory oversight
Cross-Industry
❏ Shareholders’ Voting
❏ Record Management
❏ Cybersecurity
❏ Big Data
❏ Data Storage
❏ Internet of Things
❏ Financial management
& accounting

8. Do you really need a Blockchain?

9. Do you really need a Blockchain?
Permissionless
Blockchain
Public
Permissioned
Blockchain
Private
Permissioned
Blockchain
Don’t use
Blockchain
Do you need to
store state?
Are there
multiple
writers?
Can you use
online TTP?
Are all writers
known?
Is public
verifiability
required?
Are all writers
trusted?
No No
No No
No
No
Yes Yes
Yes
Yes
Yes
Yes
Yes
No

10. Blockchain Structure
Genesis Block
Block 1 Block 2
Previous
Block Hash
Block Hash
Data
Previous
Block Hash
Block Hash
Data
Previous
Block Hash
Block Hash
Data
Previous Hash: 0000
Block Hash: 0X56
Previous Hash: 0X56
Block Hash: I6GT
Previous Hash: I6GT
Block Hash: 54B8

11. Sender: Bob
Amount: 10$
Receiver: Alice
Blockchain Structure
Genesis Block
Previous
Block Hash
Block Hash
Data
Patient: Chris M
Doctor: Dr. George Dan
Purpose: Heart Surgery

12. Why Blockchain

13. Hacker
Almost Instantly
Amount: $99
THE PROBLEM STATEMENT
A B
Location: US
Amount: $100
Location: India
Trusted Third
Party
Amount: $95
2-3 days

14. Blockchain Concepts
How does Blockchain tries to solve these problems?

15. Alex (A) Betty (B)
Chris (C)Diana (D)
Genesis: A has $100
Amount: $50
A to B: $50
Amount: $30
B to C: $30
No centralised
system?
Amount: $80
Distributed Open Ledger
Genesis: A has $100
A to B:
$50
B to C:
$30
Genesis: A has $100
A to B:
$50
B to C:
$30
Genesis: A has $100
A to B:
$50
B to C:
$30
Genesis: A has $100
A to B:
$50
B to C:
$30

16. Alex (A) Betty (B) Chris (C)
Amount: $50 Amount: $30
Block Hash: 0X56
Previous Hash: 0000
Amount: 80$
Block Hash: I6GT
Previous Hash: 0X56
Amount: 50$
Block Hash: 54B8
Previous Hash: I6GT
Amount: 30$
Tampers Data
20$
XC65
Proof of Work

17. Proof Of Work
Proof of Work, or PoW is used to confirm
transactions and produce new blocks to the chain by
using consensus algorithm.

18. How does PoW Work (P2P Network)

19. How does PoW Work (P2P Network)
51%
Consensus
Miners
Miners Miners
Miners

20. Block Time
Bitcoin
10 min

21. Alex (A) Betty (B)
Chris (C)Diana (D)
Genesis: A has
$100
A to B:
$50
B to C:
$30
Genesis: A has
$100
A to B:
$50
B to C:
$30
Amount: $10
B to D: $10
Unvalidated Transaction
MINER
MINER
Validate Transaction
Update its ledger
Publish
Transaction Fee

22. Let’s Revisit
➔ Introduction to Blockchain
➔ Significance of Blockchain Technology
➔ How does a Blockchain work
➔ When do we need it
➔ Blockchain Concepts:
◆ Proof of Work
◆ Miners
◆ Block Time and Transaction Fee

23. Types of Blockchain
Permissionless
Public
Permissioned
Private
Permissioned
Consortium
Anyone can join the
network.
Anyone can read, verify
Limited number of users
can join network
Data viewed by public
Limited number of users
can join network
Data restricted for view by
public
Intra firm validation
Limited number of users
can join network
Data restricted for view by
public
Inter firm validation

24. Real World problems

26. Smart Contracts

27. Sample Application
vodQA Super Mart

28. How does it work?
Initiates the
transaction
Confirms the
transaction from
Sender’s Account to
Buyer’s Account
Block gets Mined and
added to the Chain

29. Testing the Application
❏ Technology Stack
❏ Performance Testing
❏ Integration Testing
❏ Security Testing
❏ Smart Contract Testing
❏ Node Testing
Factors to consider while testing Blockchain Application

30. Let’s discuss
Test Strategy for Blockchain Application

31. What to Test
❏ Block Size
❏ Chain Size
❏ Load
❏ Security
❏ Transmission of Data
❏ Addition of Block
❏ Cryptographical Data

32. Blockchain Testing Tools
Ganache

33. Contract Testing
Demo

34. Functional Testing

35. References
● https://eprint.iacr.org/2017/375.pdf
● https://cointelegraph.com/explained/proof-of-work-explained
● https://www.youtube.com/watch?v=SSo_EIwHSd4
● https://www.youtube.com/watch?v=M3EFi_POhps
● https://www.youtube.com/watch?v=AQXZbPsZE64&feature=youtu.be
● https://medium.com/datadriveninvestor/do-i-really-need-blockchain-4-important-fa
ctors-to-consider-57b06e4ffbb6
● https://www.youtube.com/watch?v=ZE2HxTmxfrI
● https://www.joecolantonio.com/blockchain-testing-tools/
● https://steemit.com/ethereum/@ryuzakilost/ethereum-smart-contracts-101-hello-w
orld
● https://www.nagarro.com/en/blog/4-key-factors-to-consider-when-testing-blockchai
n-applications
● https://github.com/lipikadugar/vodQA-supermart

36. Thank You
Lipika Dugar
@lipikadugar
lipikad@thoughtworks.com
Srinivasan Sekar
srinivasantarget
sekars@thoughtworks.com