https://github.com/bethanyuo/truffle-unit-test
Develop and Unit Test Smart Contracts with Truffle
https://github.com/bethanyuo/truffle-unit-test
smart-contracts solidity truffle truffle-testing unit-testing
Last synced: 8 months ago
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Develop and Unit Test Smart Contracts with Truffle
- Host: GitHub
- URL: https://github.com/bethanyuo/truffle-unit-test
- Owner: bethanyuo
- Created: 2020-04-19T10:42:40.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2020-07-09T23:52:41.000Z (over 5 years ago)
- Last Synced: 2025-01-12T14:24:47.320Z (9 months ago)
- Topics: smart-contracts, solidity, truffle, truffle-testing, unit-testing
- Language: JavaScript
- Homepage:
- Size: 16.6 KB
- Stars: 0
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Develop and Unit Test Smart Contracts with Truffle
Build a contract which allows for funds raising. Mechanics are the same as a single Kickstarter campaign. There is a particular time to reach the goal. If this does not happen, donators are free to request a refund of transferred Ether. If a goal is reached, the owner of the smart contact can withdraw funds. We want to also allow for “anonymous” donation which is merely a transfer of funds to a smart contract. Even if we are saying anonymous, you need to know that all transactions are publicly visible Ether transfer. We are just unable to refund those funds.
## Original Source
[Michal Zalecki](https://michalzalecki.com/ethereum-test-driven-introduction-to-solidity)
## Implementing the Contract and Tests
### Setting an Owner
The first feature we want our smart contract to have is an owner. Before we start writing the first test let’s create an empty Funding contract so our tests can compile.
#### Solidity Unit Tests
Now, with an empty contract defined we can create a testing contract.
Note: Some linters will tell you that “truffle/Assert.sol” doesn’t exist. Just ignore this. Truffle will do his magic and everything will be fine.
Now we are ready to run our first test:
```bash
$ truffle test
```
Yay! If we got it right, contracts should compile without any errors. But we still don’t have any tests. We need to fix that. We want Funding to store an address of its deployer as an owner.
Each smart contract has an address. An instance of each smart contract is implicitly convertible to its address and this.balance returns contract’s balance. One smart contract can instantiate another, so we expect that owner of Funding is still the same contract. Now, to the implementation.
A sender of the message inside a constructor is a deployer. Let’s rerun the tests!
#### JavaScript Unit Tests
Now let’s create some tests in JavaScript as well.
In JavaScript, we can require a contract using `artifacts.require`. Instead of describe which you may know from other testing frameworks we use contract which does some cleanup and provides a list of available accounts. The first account is used by default during tests.
Before we run the tests, we have to create a migration for our contract in migrations/2_funding.js.
Now let’s run both tests together:
```bash
$ truffle test
```
Apart from creating a new contract during tests, we would also like to access contracts deployed through a migration:
```js
import "truffle/DeployedAddresses.sol";
```
We can now rerun tests.
### Accepting donations
Next feature on the roadmap is accepting donations. Let’s start with a test in Solidity.
We use a unit called Finney. You should know that the smallest, indivisible unit of Ether is called Wei (it fits uint type).
* 1 Ether is 10^18 Wei
* 1 Finney is 10^15 Wei
* 1 Szabo is 10^12 Wei
* 1 Shannon is 10^9 Wei
Initially, a contract has no spare ethers to transfer so we can set an initial balance. Ten Ether is more than enough. Let’s write an equivalent JavaScript test.
Now, we would like to keep track of who donated how much. Testing with JavaScript gives us an ability to test for multiple different accounts.
For tracking a balance of particular user, we can use mapping. We have to mark a function as payable, so it allows users to send Ethers along with function calls.
Let’s test and see if all of them will pass again:
```bash
$ truffle test
```
## Module
MI4: Module 1: E4