Cypress preprocessors

What is a Cypress preprocessor?

A Cypress preprocessor is the plugin responsible for preparing a support file or a test file for the browser.

The default Webpack preprocessor

By default, Cypress uses a Webpack preprocessor to transpile your test code and send it to the browser. The default Cypress Webpack config does the following things

• Transpiles ES2015+ and JSX via Babel.
• Transpiles TypeScript (how?).
• Watches and caches files.

You can customise the webpack config as shown here.

Sources

• Preprocessors – Cypress docs
• Preprocessors API – Cypress docs