Installation
Dependencies
You can install ts-jest
and dependencies all at once with one of the following commands.
NPM
npm install --save-dev jest typescript ts-jest @types/jest
Yarn
yarn add --dev jest typescript ts-jest @types/jest
Tip: If you get an error with the following npm
commands such as npx: command not found
, you can replace npx XXX
with node node_modules/.bin/XXX
from the root of your project.
Jest config file
Creating
By default, Jest can run without any config files, but it will not compile .ts
files.
To make it transpile TypeScript with ts-jest
, we will need to create a configuration file that will tell Jest to use a ts-jest
preset.
ts-jest
can create the configuration file for you automatically:
NPM
npx ts-jest config:init
Yarn
yarn ts-jest config:init
This will create a basic Jest configuration file which will inform Jest about how to handle .ts
files correctly.
You can also use the jest --init
command (prefixed with either npx
or yarn
depending on what you're using) to have more options related to Jest.
However, answer no
to the Jest question about whether or not to enable TypeScript. Instead, add the line: preset: "ts-jest"
to the jest.config.js
file afterwards.
Customizing
For customizing jest, please follow their official guide online.
ts-jest
specific options can be found here.