Setting up type checking for JavaScript

1. npm install typescript --save-dev installs TypeScript locally
2. npx tsc --init --allowJs --checkJs --noEmit creates tsconfig.json
3. Add "check-types": "npx tsc" to the scripts object in package.json
4. Run npm run check-types to check types

Type annotations can be written with JSDoc syntax. I often refer to Jsdoc cheatsheet.

Further reading

• TypeScript: Documentation - What is a tsconfig.json
• TypeScript: Documentation - JS Projects Utilizing TypeScript
• TypeScript: Documentation - Type Checking JavaScript Files
• TypeScript: TSConfig Reference - Docs on every TSConfig option