Book Image

Build Your Own Web Framework in Elixir

By : Aditya Iyengar
Book Image

Build Your Own Web Framework in Elixir

By: Aditya Iyengar

Overview of this book

Elixir's functional nature and metaprogramming capabilities make it an ideal language for building web frameworks, with Phoenix being the most ubiquitous framework in the Elixir ecosystem and a popular choice for companies seeking scalable web-based products. With an ever-increasing demand for Elixir engineers, developers can accelerate their careers by learning Elixir and the Phoenix web framework. With Build Your Own Web Framework in Elixir, you’ll start by exploring the fundamental concepts of web development using Elixir. You'll learn how to build a robust web server and create a router to direct incoming requests to the correct controller. Then, you'll learn to dispatch requests to controllers to respond with clean, semantic HTML, and explore the power of Domain-Specific Languages (DSL) and metaprogramming in Elixir. You'll develop a deep understanding of Elixir's unique syntax and semantics, allowing you to optimize your code for performance and maintainability. Finally, you'll discover how to effectively test each component of your application for accuracy and performance. By the end of this book, you'll have a thorough understanding of how Elixir components are implemented within Phoenix, and how to leverage its powerful features to build robust web applications.
Table of Contents (15 chapters)
1
Part 1: Web Server Fundamentals
4
Part 2: Router, Controller, and View
10
Part 3: DSL Design

Creating test helpers

One thing I always felt was missing from Phoenix’s testing framework was the ability to simply test whether a set of routes is defined in a router. With our reflection function, it should be relatively easy to add that ability to Goldcrest.

Let’s start by defining a RouterCase module that will house the logic for the assert_route_defined? function. We want to be able to call this function in the most idiomatic way possible; therefore, we will write this function to work with a given router, set as a module attribute in the __using__/1 macro. This means a test module using RouterCase will be a singleton to one router. Let’s go ahead and define that macro:

defmodule Goldcrest.ExUnit.RouterCase do
  defmacro __using__(opts) do
    quote do
      use ExUnit.Case
      @opts unquote(opts)
      @default_router_module __MODULE__...