I'm trying to write a test using Vitest for a function localComplement that modifies a graph represented using Cytoscape.js. Here's the function:

export function localComplement(cy: any, elements: TElement | undefined, target: string): any {    const neighbors: string[] = [];    const pairs: [string, string][] = [];    // Loop through the elements to find connections    if (elements != undefined) {        elements.edges.forEach((edge) => {            // Check if the element is an Edge            if ('source' in edge.data && 'target' in edge.data) {                // If the target matches the source, add the target to neighbors                if (edge.data.source === target) {                    neighbors.push(edge.data.target);                }                // If the target matches the target, add the source to neighbors                if (edge.data.target === target) {                    neighbors.push(edge.data.source);                }            }        });    }    // Create every neighbor composition    for (let i = 0; i < neighbors.length; i++) {        for (let j = i + 1; j < neighbors.length; j++) {            pairs.push([neighbors[i], neighbors[j]]);        }    }    pairs.forEach(([node1, node2]) => {        if (isConnected(elements, node1, node2)) {                      removeEdge(cy, elements, node1, node2);        } else {                        addEdge(cy, elements, node1, node2);        }    });    return cy;}

I wrote the following test to verify this function:

import { describe, it, expect, test } from 'vitest'; // Importing necessary functions from Vitestimport { localComplement } from './GraphUtilities.ts'; // Importing the localComplement functionimport { type TElement } from './GraphType';import cytoscape from 'cytoscape';import { gridLayout } from './config.js';// Define constants for graph elementsconst graphElementBeforeLC: TElement = {    nodes: [        { data: { id: '0' } },        { data: { id: '1' } },        { data: { id: '2' } },        { data: { id: '3' } },        { data: { id: '4' } }    ],    edges: [        { data: { id: '01', source: '0', target: '1' } },        { data: { id: '12', source: '1', target: '2' } },        { data: { id: '23', source: '2', target: '3' } },        { data: { id: '34', source: '3', target: '4' } }    ]};const graphElementAfterLC: TElement = {    nodes: [        { data: { id: '0' } },        { data: { id: '1' } },        { data: { id: '2' } },        { data: { id: '3' } },        { data: { id: '4' } }    ],    edges: [        { data: { id: '01', source: '0', target: '1' } },        { data: { id: '12', source: '1', target: '2' } },        { data: { id: '13', source: '1', target: '3' } },        { data: { id: '23', source: '2', target: '3' } },        { data: { id: '34', source: '3', target: '4' } }    ]};describe('LC test', () => {    const cy = cytoscape({        elements: graphElementBeforeLC,        style: [],        layout: gridLayout    });    const result = localComplement(cy, graphElementBeforeLC, '2');    const expectedCy = cytoscape({        elements: graphElementAfterLC,        style: [],        layout: gridLayout    });    // expect(result).toEqual(expectedCy);    it('localComplement should add edges correctly for node "2"', () => {        expect(result).toEqual(expectedCy);    });});

When I run the test, I encounter the following error:

Unhandle error

Vitest caught 1 unhandled error during the test run.This might cause false positive tests. Resolve unhandled errors to make sure your tests are not affected.

Observations

• The demo tests from Vitest run fine, but my custom test triggers this error.
• I suspect the error might be related to how I'm using Cytoscape.js or comparing the results (cy objects).
• I also verified that the localComplement function works as expected when used in isolation.