Cursor (when Jest file included) is sometimes failing to run initial request, always failing to run the 2nd request

Bug Reports
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Thanks for reporting a bug you have found in Cursor!
Please add the following info to help us diagnose your issue:

:white_check_mark: Check the forum to ensure the issue hasn’t been reported already
It hasn’t.

:lady_beetle: Provide a clear description of the bug
When I try to reference Jest in an initial message for a new chat, I sometimes see Cursor fail to process the request.

Every single time I send a followup request which references Jest, cursor fails to respond. Worth noting that I’m inside of an LWC project when these failures happen. I don’t write Jest outside of the context of LWC so I’m not sure if its reproducible outside of the LWC framework.

:counterclockwise_arrows_button: Explain how to reproduce the bug (if known)

First, setup your local to run a LWC project (Markdown instructions provided below). Then, reference a snippet of a Jest test within the LWC project in your cursor chat. Send the first message, then send a followup message.

Prerequisites

  • Node.js (v14.x or later)
  • npm (v6.x or later)

Installation Steps

1. Install Salesforce CLI

The Salesforce CLI (sf) is required to work with Salesforce projects.

npm install -g @salesforce/cli

2. Clone a Sample LWC Project (Optional)

If you don’t have an existing LWC project:

sf project generate --name lwc-test-project --template standard
cd lwc-test-project

3. Set Up Jest Testing Dependencies

Install the required packages:

npm install --save-dev @salesforce/sfdx-lwc-jest

4. Configure Jest

Make sure your project has a proper Jest configuration. Check for a jest.config.js file in your project root. If it doesn’t exist, create one with:

npx sfdx-lwc-jest --init

5. Verify Installation

Run a test command to verify your setup:

npm run test:unit

Or using the Salesforce CLI:

sf lightning test run

Sample Jest Test Structure

When providing test code to Cursor, use this structure:

import { createElement } from 'lwc';
import MyComponent from 'c/myComponent';

describe('c-my-component', () => {
    afterEach(() => {
        while (document.body.firstChild) {
            document.body.removeChild(document.body.firstChild);
        }
    });
    
    it('should do something specific', () => {
        const element = createElement('c-my-component', {
            is: MyComponent
        });
        document.body.appendChild(element);
        
        // Your assertions here
        expect(element.querySelector('div.some-class')).toBeTruthy();
    });
});

:camera: Attach screenshots or recordings (e.g., .jpg, .png, .mp4).

Shows an initial message failing to run until I removed the Jest reference. Also shows the followup message to the same thread failing to work.

:laptop: Tell us your operating system and your Cursor version (e.g., Windows, 0.x.x).
Apple M2 Pro - 14.6.1 (23G93)

Version: 0.48.8
VSCode Version: 1.96.2
Commit: 7801■■■6824585b7f2721900066bc87c4a09b740
Date: 2025-04-07T19:54:58.315Z
Electron: 34.3.4
Chromium: 132.0.6834.210
Node.js: 20.18.3
V8: 13.2.152.41-electron.0
OS: Darwin arm64 23.6.0

:prohibited: Tell us if the issue stops you from using Cursor.
Yes, it completely stops me from using it for frontend testing.

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