@lwc/jest-transformer

Compile Lightning web components for Jest tests.

About Jest Transformers

Jest transformers modify source files in preparation for tests based on regular expressions. See Jest docs for more information.

The transformer modules in this package allow LWC developers to test components that reference @salesforce modules by transforming those import statements into assignment statements that work outside of a Salesforce application container.

Installation

yarn add -D @lwc/jest-transformer

Usage

Update your jest config to point the transformer to this package:

{
    "jest": {
        "moduleFileExtensions": ["js", "html"],
        "transform": {
            "^.+\\.(js|html|css)$": "@lwc/jest-transformer"
        }
    }
}

SSR Transformer

For SSR testing, use the new transformer @lwc/jest-transformer/ssr, which compiles components to generate the compiled artifact used for SSR rendering.