Prerequisites
Node v8+
npm install -g expo-cliInstall VS Code.
Launch VS Code, open Preferences > Settings and enable Format on Save (search for "Format on Save", cause there's tons of options in there...).
Setup
Start by creating a new project with expo:
expo init react-native-foundationChoose blank (TypeScript)
Edit tsconfig.json, add the following:
{
"strict": true, /* Enable all strict type-checking options. */
"noImplicitAny": true, /* Raise error on expressions and declarations with an implied 'any' type. */
"strictNullChecks": true, /* Enable strict null checks. */
"strictFunctionTypes": true, /* Enable strict checking of function types. */
"strictPropertyInitialization": true, /* Enable strict checking of property initialization in classes. */
"noImplicitThis": true, /* Raise error on 'this' expressions with an implied 'any' type. */
"alwaysStrict": true, /* Parse in strict mode and emit "use strict" for each source file. */
/* Additional Checks */
"noUnusedLocals": true, /* Report errors on unused locals. */
"noUnusedParameters": true, /* Report errors on unused parameters. */
"noImplicitReturns": true, /* Report error when not all code paths in function return a value. */
"noFallthroughCasesInSwitch": true, /* Report errors for fallthrough cases in switch statement. */
"forceConsistentCasingInFileNames": true,
}Install eslist config (based on William Candillon's strict rules):
yarn add eslint eslint-config-react-native-wcandillon --devCreate .eslintrc file and paste the following:
{
"extends": "react-native-wcandillon"
} In package.json, add script entries for lint and tsc as follows:
{
...
"scripts": {
...
"lint": "eslint --ext .ts,.tsx .",
"tsc": "tsc"
}
}Install ESLint Visual Studio Code plugin:
https://marketplace.visualstudio.com/items?itemName=dbaeumer.vscode-eslint
Open extension settings and turn on Enable ESLint as a formatter.
Resources
[1] https://github.com/wcandillon/eslint-config-react-native-wcandillon
[2] https://gist.github.com/wcandillon/cf5882e64695ee8f572c3251e258a90b