/* Code Comments */31 posts tagged with "testing"
javascript: testing private methods
2022-11-28
|~3 min read
|487 words
Imagine the following scenario: you have a javascript module that’s relatively complicated. So complicated that you’ve broken it down into a…
javascript: making methods available for testing
2022-11-28
|~1 min read
|179 words
A fairly common experience in the Javascript world is that when you want to make a method available for testing, it needs to be exported…
jest: 'emfile: too many open files'
2022-11-28
|~1 min read
|148 words
Another entry for my Jest Tips collection! Today, we debug the mode. I frequently use Jest as a a test runner. Recently, however, I came…
testing ipados from a mac
2022-11-28
|~1 min read
|169 words
Imagine you have a iOS or iPad specific bug on your website? How do you test it? One simple way to get most of the way there before testing…
miragejs: add latency to network requests
2022-11-28
|~2 min read
|214 words
I wanted to test how my application would react if one of my endpoints was really slow. While I could have modified the network settings in…
jest-tips
2022-11-28
|~1 min read
|53 words
A collection of tips on how to use Jest. A good follow up to the collection of configuration tips. Debugging ‘Not Implemented’ Errors…
jest: watch mode
2022-11-28
|~2 min read
|397 words
To run Jest in watch mode, pass the option: By default, Jest will run tests against all changed files since the last commit, but watch mode…
mocking redux with react-testing-library
2022-11-28
|~3 min read
|549 words
In a previous post about abstracting utilities in Jest, I demonstrated how to create a wrapper for the method of the React Testing Library…
jest: asserting on classnames of css modules with identity-obj-proxy
2022-11-28
|~3 min read
|457 words
While testing specific CSS styles within a unit test is rare, it’s not uncommon to want to know if the right class was applied to a…
jest: configuring test environments
2022-11-28
|~2 min read
|345 words
By default, Jest runs tests in a “browser-like” environment using jsdom. This, however, is configurable. For example, if you’re building a…
jest: using import and es modules
2022-11-28
|~2 min read
|311 words
If you are taking advantage of ES Modules, whether through a extension or babel transpilation, it’s likely that you’re using the / syntax…
jest: a quick intro to custom runners
2022-11-28
|~3 min read
|564 words
Jest is best known as a test runner, however, it can be used to run all sorts of things, including custom runners, Go, Python, etc. As part…
jest: how to watch specific projects with `jest-watch-select-projects`
2022-11-28
|~2 min read
|268 words
Similar to other Jest plugins (e.g., typeahead), is meant to help make testing faster and easier. In the case of , the ideas is that a code…
jest: abstract away utilities with moduledirectories
2022-11-28
|~6 min read
|1041 words
In many React applications, there’s an component that is wrapped by a number of providers - themes, redux, routing, etc. When it comes to…
jest snapshots: what are they, how to use them, and serializers
2022-11-28
|~9 min read
|1710 words
When it comes to testing UIs, there’s a lot to keep track of. Sometimes it can be helpful to just make sure that if a component changes, you…
jest: configuring jest to resolve modules
2022-11-28
|~2 min read
|394 words
A common pattern within Javascript applications is to use Webpack or Typescript to treat internal directories as modules so that they can be…
debugging jest: step through jest code with `--inspect-brk`
2022-11-28
|~1 min read
|195 words
In Debugging Node, I discussed how to use Node’s flag to debug a Node process. This is also really helpful for when we want to step through…
miragejs: generating reasonable data
2022-11-28
|~3 min read
|510 words
MirageJS is an API mocking tool for Frontend developers and came out of the Ember community. It’s pretty awesome. Not only can you use it to…
jest: how to configure jest for testing javascript applications
2022-11-28
|~2 min read
|259 words
A collection of posts on how to configure Jest to add various capabilities. Many of these posts are inspired by Kent C. Dodds’ Testing…
kcd: static analysis testing javascript applications
2022-11-28
|~1 min read
|9 words
anatomy of an eslintrc static testing tools eslint
anatomy of an eslintrc
2022-11-28
|~5 min read
|917 words
Anatomy of an .eslintrc I’ve written about ESLint a few times in the past - normally in the context of something breaking or setting up a…
test object factory
2022-11-28
|~5 min read
|885 words
Continuing my foray into becoming a better tester, today, I’m exploring the Test Object Factory. This pattern shares some similarities with…
testing: mocking strategies
2022-11-28
|~10 min read
|1834 words
When it comes to testing our code, it may be desireable to avoid following the normal code path all the way. Some examples of calls that we…
notes on why good developers write bad tests
2022-11-28
|~4 min read
|614 words
In 2019, Michael Lynch gave a talk at PyTexas titled “Why Good Developers Write Bad Tests”. https://youtu.be/hM_ex4-xu4E I was watching it…
jest: mocking node's fs
2022-11-28
|~5 min read
|993 words
I hit some road blocks with recently which are motivating a refactoring with an eye toward reliability through testing.1 Since ’s primary…
ember: testing services
2022-11-28
|~5 min read
|806 words
Today, I built a small feature in Ember. In my ongoing effort to improve with testing, I was about ready to ask for a review when I realized…
asserting errors in pytest
2022-11-28
|~6 min read
|1053 words
Imagine a function that, under certain conditions expects to throw an error. How might we test that with Pytest? Pytest offers two…
pytest marker basics
2022-11-28
|~10 min read
|1825 words
Within Python’s testing framework , markers can decorate a test method (i.e. a method which has a name beginning and inside a file prefixed…
mocks and spies: inspecting console messages with jest
2022-11-28
|~3 min read
|466 words
I was working recently on a project where a function would print to the console when it was executed. I was practicing writing more tests…
testing - chai tests and database connection pools
2022-11-28
|~3 min read
|433 words
I’m writing some integration tests for an app that is confirming database queries are working the way I’m expecting. In order to prep the…
how to test your api using curl & postman
2022-11-28
|~2 min read
|302 words
The other day, I found myself making some changes to a network request for our application. By navigating to a specific page, I knew I’d…