Web developer's learning journal
Recently I decided to teach myself AWS, but I soon started to wonder why and when to use AWS EC2 rather than renting a server from a conventional server provider. Why? the main reasons are… EC2 seems so convoluted with many acronyms and terms (e.g. AMI, ESB, EFS), all of which makes it difficult to …
If you’ve used Nginx, you may have come across this error. 2019/04/12 06:43:24 [error] 11365#0: *257 upstream sent too big header while reading response header from ups tream, client: 127.0.0.1, server: hiroki-example.com, request: “POST /payment HTTP/1.1”, upstream: “fastcgi://127.0.0.1:9000”, host: “hiroki-example.com”, referrer: “http://hiroki-example.com/payment” I’ve seen this many times, but haven’t really tried to understand it deeply. In …
I’ve just finished setting up Nginx on my brand new PC running on CentOS 7 with PHP7.2. I used to use Ubuntu 16 with PHP7.0 and was quite familiar with the combo. I thought that setting up Nginx on CentOS wouldn’t be that different from doing so on Ubuntu, which wasn’t really true. It took …
When testing wit Jest, the test is working in a command line environment, which mimics the browser. However, this fake browser environment doesn’t allow us to interact with APIs outside of it. Then, how do we make AJAX requests while testing with Jest? Assuming that you use axios for calling API calls, moxios will be the …
I’ve been teaching myself how to write tests for React app. It seems that Enzyme is the de facto standard for it. Here is what I’ve learned for testing components with form elements (e.g. <input />). Setting up First of all, install the modules. npm install –save enzyme enzyme-adapter-react-16 NOTE: It depends on the version …
Draw a component treemap with basic component structures The first step to take is to draw a rough idea as to how the whole app will look like. Typically, you either… get a design plan from your client or designer. Or, develop a design plan by yourself Based on the design, you are going to …
1. Definition It provides an interface for creating families of related or dependent objects without specifying their concrete classes. 2. Case study 2.1 The problem You’re creating a car manufacturer simulator, where you can simulate the process of manufacturing cars. As you may know, petrol cars and diesel cars need different parts in their fuel systems, …
1. Definition Defines an interface for creating an object, but lets subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses. 2.Case study I’m from Japan, where you’ll see different types of Miso (an ingredient of traditional soup) at the supermarket in different regions. For example, in Eastern areas, dark red Miso …
1. Definition The Simple Factory is not a pattern discussed in the GoF book. This article is written by referring to Head First Design Patterns. The Simple Factory pattern can be defined as a pattern where … 1. you have a factory class responsible for creating instances. 2. then, you let a client class use the …
1. Definition The strategy pattern defines a family of algorithms, encapsulate each one, and make them interchangeable 2. Case study 2.1 The Problem A couple of years ago, you started a restaurant. Your restaurant had become so successful that you started to hire employees. Your employee’s payments were determined by … Wage rate × working hours Their …