---
title: Guide to jest and @swc/jest
author: powerfulyang
date: 2023-03-08
public: true
summary: 使用正确的姿势使用 jest 或 @swc/jest
tags: 
    - jest
    - jsdom
    - Loading subresources
    - @swc/jest
---

## testEnvironmentOptions

### Loading subresources

By default, jsdom will not load any subresources such as scripts, stylesheets, images, or iframes. If you'd like jsdom to load such resources, you can pass the `resources: "usable"` option, which will load all usable resources. Those are:

* Frames and iframes, via `<frame>` and `<iframe>`
* Stylesheets, via `<link rel="stylesheet">`
* Scripts, via `<script>`, but only if `runScripts: "dangerously"` is also set
* Images, via `<img>`, but only if the `canvas` npm package is also installed (see "[Canvas Support](#canvas-support)" below)

When attempting to load resources, recall that the default value for the `url` option is `"about:blank"`, which means that any resources included via relative URLs will fail to load. (The result of trying to parse the URL `/something` against the URL `about:blank` is an error.) So, you'll likely want to set a non-default value for the `url` option in those cases, or use one of the [convenience APIs](#convenience-apis) that do so automatically.




Guide to jest and @swc/jest

---
title: Guide to jest and @swc/jest
author: powerfulyang
date: 2023-03-08
public: true
summary: 使用正确的姿势使用 jest 或 @swc/jest
tags: 
    - jest
    - jsdom
    - Loading subresources
    - '@swc/jest'
---

## testEnvironmentOptions

### Loading subresources

By default, jsdom will not load any subresources such as scripts, stylesheets, images, or iframes. If you'd like jsdom to load such resources, you can pass the `resources: "usable"` option, which will load all usable resources. Those are:

* Frames and iframes, via `<frame>` and `<iframe>`
* Stylesheets, via `<link rel="stylesheet">`
* Scripts, via `<script>`, but only if `runScripts: "dangerously"` is also set
* Images, via `<img>`, but only if the `canvas` npm package is also installed (see "[Canvas Support](#canvas-support)" below)

When attempting to load resources, recall that the default value for the `url` option is `"about:blank"`, which means that any resources included via relative URLs will fail to load. (The result of trying to parse the URL `/something` against the URL `about:blank` is an error.) So, you'll likely want to set a non-default value for the `url` option in those cases, or use one of the [convenience APIs](#convenience-apis) that do so automatically.




-Expand 7 lines ...
     - jest
     - jsdom
     - Loading subresources
-    - @swc/jest
+    - '@swc/jest'
 ---
 ## testEnvironmentOptions
-Expand 11 lines ...