What is a State Machine?

Finite State Machines (FSM, or in the context of this post, simply "State Machines") are a methodology for modeling the behavior of an entity with an established lifecycle. The lifecycle is defined by an enumerated set of states known at the time of implementation (this is where the term . . .

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A commonly misunderstood concept in Node.js is the difference between setTimeout, setImmediate, and process.nextTick. While all three functions are used to schedule the execution of a function, it is important to understand when Node.js will execute them.

Consider the following example:

setImmediate(() => console.log('Set . . .

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I wanted to quickly mention a trick I use to reduce the boilerplate code you'll often encounter when executing similar test cases. Instead of defining each test separately:

const { describe, it } = require('mocha');
const { expect } = require('chai');

const app = require('../../index.js');
 . . .

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Enumerations are essential to writing good software. Enumerations provide a clear understanding of the set of values that can be used for a property. This ensures we can constrain input to the set of values in the enumeration. Enumerations also signal to the reader the intended behavior of model instances (particularly if the enumerated field . . .

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I'm surprised how little custom errors are used in Node.js and I don't understand why.

I was integrating an open source library last week into a project and I was trying to write unit tests covering all failure cases one could expect with the library. The library, however, didn't make use of explicit error cases. This . . .

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I was troubleshooting a bug recently when I noticed an unrelated issue with one of my microservices. We were experiencing a failure in a non-critical component responsible for notifying our internal staff of a minor issue in our business workflow.

This was an issue our development team, extremely thorough QA team, and Ops team missed . . .

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