"How do I get started with Node?" is a commonly heard question in #Node.js. This gist is an attempt to compile some of the answers to that question. It's a perpetual work-in-progress.
Understand that it's going to take time to learn Node.js, just like it would take time to learn any other specialized topic - and that you're not going to learn effectively just by reading things, or following tutorials or courses. Get out there and build things! Experience is by far the most important part of learning, and shortcuts to this simply do not exist.
Avoid "bootcamps", courses, extensive books, and basically anything else that claims to teach you programming (or Node.js) in a single run. They all lie, and what they promise you simply isn't possible. That's also the reason this post is a list of resources, rather than a single book - they're references for when you need to learn about a certain topic at a certain point in time. Nothing more, nothing less.
There's also no such thing as a "definitive guide to Node.js", or a "perfect stack". Every project is going to have different requirements, that are best solved by different tools. There's no point in trying to learn everything upfront, because you can't know what you need to learn, until you actually need it.
In conclusion, the best way to get started with Node.js is to simply decide on a project you want to build, and start working on it. Start with the simplest possible implementation of it, and over time add bits and pieces to it, learning about those bits and pieces as you go. The links in this post will help you with that.
Table of contents
- The Node.js platform
- Setting up your environment
- Functional programming
- Module patterns
- Code architecture
- Coming from other languages or platforms
- Useful modules
- Writing C++ addons
- Writing Rust addons
- Odds and ends
- Future additions to this list
These links will help you refresh your knowledge of JS, and make sure that you understand the OOP model correctly.
undefinedrelate to each other.
- However, in practice, you shouldn't use that, and you should use Promises instead. Whereas it is very easy to mess up CPS code, that is not an issue with Promises - error handling is much more reliable, for example. This guide should give you a decent introduction.
- A callback should be either consistently synchronous, or consistently asynchronous. You don't really have to worry about this when you're using Promises (as they ensure that this is consistent), but this article still has a good explanation of the reasons for this. A simpler example can be found here.
thisvariable refers to. Often you don't need inheritance at all - this gist shows an example of creating an object in the simplest possible way.
The Node.js platform
- The easiest way to install Node.js on Linux and OS X, is to use
nvm. The instructions for that can be found here. Make sure you create a
defaultalias (as explained in the documentation), if you want it to work like a 'normal' installation.
- If you are using Windows: You can download an installer from the Node.js website. You should consider using a different operating system, though - Windows is generally rather poorly suited for software development outside of .NET. Things will be a lot easier if you use Linux or OS X.
- The package manager you'll use for Node.js, is called NPM. While it's very simple to use, it's not particularly well-documented. This article will give you an introduction to it.
- Don't hesitate to add dependencies, even small ones! Node.js and NPM are specifically designed to make this possible without running into issues, and you will get big benefits from doing so. This post explains more about that.
- The module system is very simple. The Node.js documentation explains this further.
- MongoDB is commonly recommended and used with Node.js. It is, however, extremely poorly designed - and you shouldn't use it. This article goes into more detail about why you shouldn't use it. If you're not sure what to use, use PostgreSQL.
- The rest of the documentation for all the modules included with Node.js, can be found here.
Setting up your environment
- If you're running into issues on Windows, try these instructions from Microsoft.
- This article gives an introduction to
reduce- three functional programming operations that help a lot in writing maintainable and predictable code.
- This gist shows an example of using those with Bluebird, the Promises library that I recommended in the Promises Reading Guide.
A commonly used pattern is the
EventEmitter - this is exactly what it sounds like; an object that emits events. It's a very simple abstraction, but helps greatly in writing loosely coupled code. This gist illustrates the object, and the full documentation can be found here.
The 'design' of your codebase matters a lot. Certain approaches for solving a problem work better than other approaches, and each approach has its own set of benefits and drawbacks. Picking the right approach is important - it will save you hours (or days!) of time down the line, when you are maintaining your code.
I'm still in the process of writing more about this, but so far, I've already written an article that explains the difference between monolithic and modular code and why it matters. You can read it here.
If you want to build a website or web application, you'll probably find Express to be a good framework to start with. As a framework, it is very small. It only provides you with the basic necessities - everything else is a plugin.
If this sounds complicated, don't worry - things almost always work "out of the box". Simply follow the
README for whichever "middleware" (Express plugin) you want to add.
To get started with Express, simply follow the below articles. Whatever you do, don't use the Express Generator - it generates confusing and bloated code. Just start from scratch and follow the guides!
- Installing Express (some of this was already covered in the NPM guide above)
- A Hello World example
- Using template engines
- Writing Middleware
- Using Middleware
- Static File Handling (this is middleware, too!)
- Error Handling
To get a better handle on how to render pages server-side with Express:
- Rendering pages server-side with Express (and Pug) (a step-by-step walkthrough, work in progress)
Some more odds and ends regarding about Express:
- Some FAQs (don't use MVC, however - this is why.)
- Express Behind Proxies
- The full Express API documentation
- Making something "globally available" in an Express application
- Writing configurable middleware (using the same technique as the parametric modules I showed earlier)
Combining Express and Promises:
- A short article explaining how to use
- An example, also explaining what would happen if you didn't handle errors.
Some common Express middleware that you might want to use:
- Sessions: express-session, with connect-session-knex if you are using Knex.
- Message flashing: connect-flash
- Handling request payloads ("form/POST data"): body-parser
- Handling uploads and other multipart data: multer if you want it written to disk like PHP would do, or connect-busboy if you want to interact with the upload stream directly.
- Access logs: morgan
- OAuth/OpenID integration: Passport
Coming from other languages or platforms
- If you are used to PHP or similar: Contrary to PHP, Node.js does not use a CGI-like model (ie. "one pageload is one script"). Instead, it is a persistent process - your code is the webserver, and it handles many incoming requests at the same time, for as long as the process keeps running. This means you can have persistent state - this gist shows an example of that.
- If you are used to synchronous platforms: This gist illustrates the differences between a (synchronous) PHP script and an (asynchronous) Node.js application.
Note that this advice isn't necessarily complete. It answers some of the most common questions, but your project might have special requirements or caveats. When in doubt, you can always ask in the #Node.js channel!
Also, keep in mind the golden rule of security: humans suck at repetition, regardless of their level of competence. If a mistake can be made, then it will be made. Design your systems such that they are hard to use incorrectly.
- Sessions: Use something that implements session cookies. If you're using Express, express-session will take care of this for you. Whatever you do, don't use JWT for sessions, even if many blog posts recommend it - it will cause security problems. This article goes into more detail.
- Password hashing: Use
scrypt. This wrapper module will make it easier to use.
- CSRF protection: You need this if you are building a website. Use csurf.
- XSS: Every good templater will escape output by default. Only use templaters that do this (such as Jade or Nunjucks)! If you need to explicitly escape things, you should consider it insecure - it's too easy to forget to do this, and is practically guaranteed to result in vulnerabilities.
- SQL injection: Always use parameterized queries. When using MySQL, use the
node-mysql2module instead of the
node-mysqlmodule - the latter doesn't use real parameterized queries. Ideally, use something like Knex, which will also prevent many other issues, and make your queries much more readable and maintainable.
- Random numbers and values: Generating unpredictable random numbers is a lot harder than it seems.
Math.random()will generate numbers that may seem random, but are actually quite predictable to an attacker. If you need random values, read this article for recommendations. It also goes into more detail about the types of "randomness" that exist.
- Cryptography: Follow the suggestions in this gist. Whatever you do, do not use the
- Vulnerability advisories: The Node Security Project keeps track of known vulnerabilities in Node.js modules. Services like VersionEye will e-mail you, if your project uses a module that is found vulnerable.
This is an incomplete list, and I'll probably be adding stuff to it in the future.
- Determining the type of a value: type-of-is
- Date/time handling: Moment.js
- Making HTTP requests: bhttp
- Clean debugging logs: debug
- Cleaner stacktraces and errors: pretty-error
- Markdown parsing: marked
- HTML parsing: cheerio (has a jQuery-like API)
- WebSockets: ws
- Don't run Node.js as root, ever! If you want to expose your service at a privileged port (eg. port 80), and you probably do, then you can use authbind to accomplish that safely.
- Your project is ready for release! But... you should still pick a license. This article will give you a very basic introduction to copyright, and the different kind of (common) licenses you can use.
Scalability is a result of your application architecture, not the technologies you pick. Be wary of anything that claims to be "scalable" - it's much more important to write loosely coupled code with small components, so that you can split out responsibilities across multiple processes and servers.
Is something not working properly? Here are some resources that might help:
npm installcausing an error? Use this error explaining tool to find out what's wrong.
DeprecationWarning: Using Buffer withoutnew
will soon stop working.- the solution for this can be found here.
The first rule of optimization is: do not optimize.
The correct order of concerns is security first, then maintainability/readability, and then performance. Optimizing performance is something that you shouldn't care about, until you have hard metrics showing you that it is needed. If you can't show a performance problem in numbers, it doesn't exist; while it is easy to optimize readable code, it's much harder to make optimized core more readable.
There is one exception to this rule: never use any methods that end with
Sync - these are blocking, synchronous methods, and will block your event loop (ie. your entire application) until they have completed. They may look convenient, but they are not worth the performance penalty.
Now let's say that you are having performance issues. Here are some articles and videos to learn more about how optimization and profiling works in Node.js / V8 - they are going to be fairly in-depth, so you may want to hold off on reading these until you've gotten some practice with Node.js:
- Common causes of deoptimization
- Monomorphism, and why it is important
- Tuning Node.js
- A tour of V8: object representation
- Node.js in flames
- Realtime Node.js App: A Stress Testing Story (using Socket.IO)
- A bigger list of resources about V8 optimization and internals can be found here.
If you're seeing memory leaks, then these may be helpful articles to read:
These are some modules that you may find useful for profiling your application:
- node-inspector: Based on Chrome Developer Tools, this tool gives you many features, including CPU and heap profiling. Also useful for debugging in general. Since Node.js v6.3.0, you can also connect directly using Chrome Developer Tools.
- heapdump: On-demand heap dumps, for later analysis. Usable from application code in production, so very useful for making a heap dump the moment your application goes over a certain heap size.
- memwatch-next: Provides memory leak detection, and heap diffing.
Writing C++ addons
These are some resources on that:
- The addon documentation
nan, an abstraction layer for making your module work across Node.js versions (you should absolutely use this)
node-gyp, the build tool you will need for this purpose
- V8 API documentation for every supported Node.js version
Writing Rust addons
Neon is a new project that lets you write memory-safe compiled extensions for Node.js, using Rust. It's still pretty new, but quite promising - an introduction can be found here.
Odds and ends
Some miscellaneous code snippets and examples, that I haven't written a section or article for yet.
- Named logging in Gulp: https://gist.github.com/joepie91/e7d66ffdb17d1ea69c56
- Cached image: https://gist.github.com/joepie91/cee42198b6bc6a24ea44
- Combining Gulp and Electron: https://gist.github.com/joepie91/f81cdbc1b45d52ab4b87
Future additions to this list
There are a few things that I'm currently working on documenting, that will be added to this list in the future. I write new documentation as I find the time to do so.
- Node.js for PHP developers (a migration guide) - In progress.
- A comprehensive guide to Promises - Planned.
- A comprehensive guide to streams - Planned.
- Error handling mechanisms and strategies - Planned.
- Introduction to HTTP - Planned.
- Writing a secure authentication system - Planned.
- Writing abstractions - Planned.