Andrés andresgutgon

Testing: The little mocker

This is an example trying to apply some lessons learned from Uncle Bob's article The little mocker

In this gist first I'll explain what I learned. Then I'll show you what the code does and finally how I tested the code.

What I learned

When we're making unit test we want to focus on the code we want to test not external dependencies that are not under our control. To make life easier and being able to test on isolation our code without side effects from the rest of the world we use test doubles. Test doubles try to simulate behavior that is in our code but belongs to external agents/objects.

	import { MeasuringSystem, MeasuringUnit, MeasuringUnitKind } from "db"

	const COMMON = { unitless: { count: MeasuringUnit.count } }

	type UnitGroup = Record<MeasuringUnitKind, Record<string, MeasuringUnit>>
	type SystemUnits = Record<MeasuringSystem, UnitGroup>

	export const units: SystemUnits = {
	[MeasuringSystem.METRIC]: {
	...COMMON,

	import { Suspense, ReactNode } from 'react'
	import { Routes, RedirectError, useSession } from "blitz"
	import cn from "classnames"

	import Layout from "app/core/layouts/Layout"
	import type { LayoutProps } from "app/core/layouts/Layout"

	const SUPERADMIN_ROLE = 'SUPERADMIN' as never

	type CheckIsAdminProps = { children: ReactNode }

	version: "3.3"

	services:
	traefik:
	image: traefik:$TRAEFIK_VERSION
	command:
	- --log.level=DEBUG # DEBUG, INFO, WARN
	- --global.sendAnonymousUsage=false
	- --api.insecure

	# SWAP The fcsonline way
	# First make yourself sudo like this

	sudo su

	# The copy these lines in the console
	fallocate -l 2G /swapfile
	chmod 600 /swapfile
	mkswap /swapfile
	swapon /swapfile

	### Keybase proof

	I hereby claim:

	* I am andresgutgon on github.
	* I am andresgutgon (https://keybase.io/andresgutgon) on keybase.
	* I have a public key ASCacdfdFvZwrBEN1muWuTNiEETe2c4gzbkUikI07TRL2Qo

	To claim this, I am signing this object:

	<div style="clear: both;">
	<img src="" alt="" style="float: left;margin-right: 10px;"/>
	<div></div>
	</div>

	<!DOCTYPE html>
	<html>
	<head></head>
	<style>
	* {
	box-sizing: border-box;
	}
	body {
	font-size: 13px;
	}

	var _ = require('underscore');
	var config = require('./grunt/webpack/config.js');
	var plugins = require('./grunt/webpack/plugins.js');

	const env = 'development';

	var environments = {
	production: {
	plugins: plugins[env],
	devtool: 'source-map',

	'use strict';

	var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol ? "symbol" : typeof obj; };

	var _extends = Object.assign \|\| function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };

	function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }
	'use strict';

	var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol ? "symbol" : typeof obj; };