Developer and freeCodeCamp camper Flavio Copes has published his entire Node.js Handbook online for free - both on freeCodeCamp's Medium publication and as a .pdf file. You can read it here.
In his handbook, Flavio covers a variety of Node.js concepts, including:
- How to install Node.js
- The V8 JavaScript Engine
- How to read environment variables from Node.js
- How to use the Node.js REPL
- An introduction to npm
- The package.json guide
- The package-lock.json file
- How to update all the Node dependencies to their latest version
- Semantic Versioning using npm
- The npx Node Package Runner
- The Event Loop
- Timers
- Asynchronous Programming and Callbacks
- Promises
- Async and Await
- The Node Event emitter
- How HTTP requests work
- Using WebSockets in Node.js
- Reading and writing files with Node
- Node.js Streams
- The basics of working with MySQL and Node
- And many other topics
You can read Flavio's full Node.js Handbook here (95 minute read).