Configuration

cljest config

By default, cljest is either able to infer the information it needs or has sensible defaults. If you're just starting out and your tests are in a path in the classpath that you execute cljest with, you probably don't need to configure anything yet.

However, if you're doing something more advanced, like you need a custom setup file or if you need to define something for the compiler, below describes how you can set up a custom config file.

What is the default config?

Assuming that your classpath has a relative src directory exposed, the following config will be the default:

{:test-src-dirs ["src"]
 :ns-suffixes [-test]
 :setup-ns cljest.setup
 :port 9003
 :compiler-options {:closure-defines {}}}

Custom configuration

To create a custom configuration, first create a file called cljest.edn that lives at the root of your project. This is typically where your deps.edn file exists, and will need to live next to your jest.config.js file.

Config keys in detail

In more detail, the above keys are:

• :test-src-dirs: a vector of strings that point to directories that contain test files, relative to cljest.edn. Uses relative paths in your classpath as the default.

  These directories should correspond to a directory in the classpath, so if your deps.edn file has src/dev as an entry and you have tests there, make sure that test-src-dirs uses src/dev rather than src. If you set the wrong path here, you will get cryptic error message with weird looking namespaces.

• :ns-suffixes: a vector of symbols that are the endings of a test namespace. Defaults to [-test].

• setup-ns: a symbol which is a resolvable namespace that should be loaded before each test. Defaults to cljest.setup.

  Note: if you specify an alternative setup-ns, you must require cljest.setup for matchers to correctly work.

• port: an integer that corresponds to the port that will be used when starting cljest in watch mode. Defaults to 9003.

• compiler-options: a map of ClojureScript compiler options. At the moment only closure-defines is allowed. Please raise a ticket if there's a compiler option you would like to be allowed.

Example:

{:test-src-dirs ["src/app"]
 :ns-suffixes [-spec -test]
 :setup-ns my.cool.preloads.ns}

Jest config

In general, you don't need much cljest specific config for Jest, namely a couple keys in your jest.config.js file and a couple lines in your jest.setup.js file.

// jest.config.js
module.exports = {
    preset: 'jest-preset-cljest',
    setupFilesAfterEnv: ['jest.setup.js'],
}

// jest.setup.js
const { loadSetupFile } = require("jest-preset-cljest/utils");

loadSetupFile();

If you're not using another preset, this is all you need to get started, and details on further Jest configuration please see the Jest configuration documentation.

I need to use jest-preset-cljest with another preset

In the event you need to use jest-preset-cljest with another preset, such as if you're using jest-expo for your React Native components, you can use require jest-preset-cljest as a normal object and extend from it. Just keep in mind the following:

• As mentioned, you can import the preset as an object which you can extend by requiring or importing jest-preset-cljest, e.g. const jestShadowCljest = require('jest-preset-cljest')
• Make sure you deep merge the preset in with your config and other potential presets using something like lodash.merge. Without deeply merging you will likely run into issues related to things like roots or Jest's Haste mechanism.