31 July 2018

Making blockchains simple

One of the challenges of building blockchain solutions is testing it. Chronicle Accelerate has a framework to make adding custom transactions with the state using data-driven tests. i.e. without the need to write code.

Example: Appreciation

The following application allows participants to show appreciation for each other by giving "likes". They have a fixed number of likes to give each other each week on a use or lose it basis. Users with the most likes might get a reward on a monthly basis, which halves their likes.

The data-driven tests are available here Appreciation Give tests

setup.yaml sets up the test, giving it an initial state

openingBalance: {
  publicKey: !!binary RWUHCYzTzADL+4kJ9r90rWHBo6J/Wng5FmlXFjv8bd8=, (1)
  amount: 100.0
}
---
openingBalance: {
  publicKey: !!binary Sq1s3liIh6LkceZYP+qh6MlMRRqCNJ5Dvl9oyAiZHe8=, (2)
  amount: 10.0
}
---

1	Public key of account 1
2	Public key of account 2

in.yaml defines the messages whose outputs are tested

startBatch: {
  batchKey: !!binary RWUHCYzTzADL+4kJ9r90rWHBo6J/Wng5FmlXFjv8bd8=, (1)
  batchTimeUS: "1970-01-01T00:00:00"
}
---
give: { (2)
  publicKey: !!binary Sq1s3liIh6LkceZYP+qh6MlMRRqCNJ5Dvl9oyAiZHe8=, (3)
  amount: 20.0 (4)
}
---
endBatch: ""
---

1	Account 1
2	gives
3	Account 2
4	20.0 likes

produces an output of

output.yaml describes the extends outputs

---
to: !!binary RWUHCYzTzADL+4kJ9r90rWHBo6J/Wng5FmlXFjv8bd8= (1)
onBalance: { (2)
  publicKey: !!binary RWUHCYzTzADL+4kJ9r90rWHBo6J/Wng5FmlXFjv8bd8=,
  amount: 80.0 (3)
}
to: !!binary Sq1s3liIh6LkceZYP+qh6MlMRRqCNJ5Dvl9oyAiZHe8= (4)
onBalance: { (5)
  publicKey: !!binary Sq1s3liIh6LkceZYP+qh6MlMRRqCNJ5Dvl9oyAiZHe8=,
  amount: 30.0 (6)
}
---
---

1	Account 1
2	is notified that it’s balances is now
3	80.0 likes
4	Account 2
5	is notified that it’s balance is now
6	30.0 likes

The two key classes are the gateway class

VanillaAppreciationGateway.java

and the post blockchain class is

VanillaAppreciationTransactionListener.java

lost.town is a domain I use for examples and games I write.

If you would like to get updates on Chronicle Accelerate, join us on Twitter

If you would like to see how our platform can be used to build your blockchain solution Contact us on sales@chronicle-software.com