# Getting Started
This project was bootstrapped with [Create React App](https://github.com/facebook/create-react-app).
## Available Scripts
In the project directory, you can run:
### `yarn install`
Installs dependencies
### `yarn start`
Runs the app in the development mode.\
Open [http://localhost:3010](http://localhost:3000) to view it in the browser.
The page will reload if you make edits.\
You will also see any lint errors in the console.
### `yarn build`
Builds the app for production to the `build` folder.\
It correctly bundles React in production mode and optimizes the build for the best performance.
The build is minified and the filenames include the hashes.\
Your app is ready to be deployed!
See the section about [deployment](https://facebook.github.io/create-react-app/docs/deployment) for more information.
## Project structure
- `App/` - React App root component, contains global providers and routing configuration
- `components/` - React components
- `pages/` - Page components
- `lib/` - Infrastructure code independent of business logic (widely used in the project base modules and functions for interaction with data sources, common utils, etc.)
- `contracts`
- `callContract.ts` - e.g. base function for requesting contracts
- `chains`
- `utils.ts`
- `constants.ts`
- `request.js` - example base function for http requests
- `useLockBodyScroll.ts` - common ui hook
- `Helpers.js` - Unstrcutured legacy code (moved from Helpers.js)
- `domain/` - Project specific domain logic separated by entities and features, may contain
data fetching, formatting, types and constants
- `orders/` - Example entity folder
- `types.ts` - Entity related types
- `utils.ts` - Functions for calculations and formatting, can be split into several files
- `contracts.ts` - Contracts calls
- `backend.ts` - Http requests
- `graph.ts` - Subgraph queries
- `constants.ts`
- `hooks.ts`
- `legacy.js` - Unstructured legacy code (moved from Api/index.js)
- `config/` - Often manually changed or environment-dependent global configs
- `styles/` - Global styles
- `img/` - Images
- `abis/` - Contract abis
- `fonts/`
## Architecture guides
### React components
- Try to keep it simple and modular - only one component per file, Child components should be put separately
- Keep a **flat** components folder structure - do not nest components inside other components folders
- Keep styles and components together in the same folder
- Code, independent of state and props should be moved outside component body
- In general components should countain only ui logic, all resusable data processing code should be moved to the `domain` or `lib` folder, component-specific calculations
can be wrapped in custom hooks or functions and placed near component
- Try to keep definition order inside component body:
1. State - useState, useFetchedData, etc.
2. Calculated variables from state and props
3. Functions reused in the component, e.g. event handlers
4. useEffect
5. Render
Example component structure
- `components/`
- `SwapBox`
- `SwapBox.js`
- `SwapBox.css`
- `getErrorMessage.js` - only a component-specific logic
Example component body
```(javascript)
// components/SwapComponent/SwapComponent.tsx
import {useInfoTokens} from 'domain/tokens/contracts'
import {processSwap} from 'domain/exchange/contracts'
...
export function SwapComponent(props: Props) {
const infoTokens = useInfoTokens(props.chainId, ...);
const [selectedTokenAddress, setSelectedTokenAddress] = useState()
const [amount, setAmount] = useState()
const {tokenAmount, swapLimits, fees, ...} = useSwapState(
props, {infoTokens, selectedTokenAddress, amount}
)
...
useEffect(..., []);
async function onButtonClick() {
...
await processSwap(...)
}
return (
....
}
```
Optional separating component state evaluation if it contains a lot of logic which is highly
dependent on props or a state of the component.
```(javascript)
components/SwapComponent/useSwapState.ts
import {getTokenAmount} from 'domain/tokens/apiContracts'
import {getSwapLimits} from 'domain/exchange/swap-utils'
function useSwapState(props, {selectedTokenAddress, infoTokens, amount}) {
const infoTokens = useInfoTokens(props.chainId, ...);
const tokenAmount = getTokenAmount(infoTokens, selectedTokenAddress, ...)
const swapLimits = getSwapLimits(infoTokens, amount)
const swapFee = ...
const fees = ...
...some calculations
return {...}
}
```
---
### DataFlow
Divide a code into appropriate areas of responsibility and keep the dependencies flow:
```
config -> lib (infrastructure) -> domain -> components -> pages
```
Each layer can use code from itself or from the left side. For example `lib`-modules can require `config` and other `lib`-modules, but not `domain`-modules or `components`.
Also `pages` can depend on `components`, but not vice versa.
### Typescript
- Write a new code in Typescript as far as possible
- Components should have `.tsx` exstension
- While migration, there are some issues when using
js components inside tsx - all props are considered as required.
To solve this, define default values for unused props or put
jsDoc description when this is difficult
Example
```(javascript)
/**
* @param {any} props
*/
function Button(props) {...}
```
---