vitest 3 causes emotion ThemeProvider tests to fail

[bmcallis]

Describe the bug

After updating to vitest@3 our tests using ThemeProvider from @emotion/react and rendering components with @testing-library/react are failing because the theme object that gets passed to the component is an empty object. The tests work fine with vitest@2 and render correctly in the browser.

Reproduction

Here is a simple example of the issue

import React from 'react';
import { describe, expect, it } from 'vitest';
import { ThemeProvider } from '@emotion/react';
import styled from '@emotion/styled';
import { render } from '@testing-library/react';

const theme = {
  colors: {
    primary: 'hotpink',
  },
};

const SomeText = styled.div`
  color: ${(props) => {
    console.log('SomeText theme', props.theme);
    return props.theme.colors.primary;
  }};
`;


describe('ColorGrid', () => {
  it('Should render themed text with wrapper', () => {
    const { container } = render(<SomeText />, { wrapper: (props) => (<ThemeProvider theme={theme} {...props} />) });
    expect(container).toMatchSnapshot();
  });

  it('Should render themed text with inline provider', () => {
    const { container } = render(<ThemeProvider theme={theme}><SomeText /></ThemeProvider>);
    expect(container).toMatchSnapshot();
  });
});

And there is a minimal repo to reproduce the issue here: https://gitlab.com/bmcallis/vitest-bug

System Info

System:
    OS: macOS 15.2
    CPU: (12) arm64 Apple M2 Max
    Memory: 15.05 GB / 96.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.12.0 - ~/.nvm/versions/node/v22.12.0/bin/node
    npm: 11.0.0 - ~/.nvm/versions/node/v22.12.0/bin/npm
  Browsers:
    Chrome: 131.0.6778.265
    Safari: 18.2
  npmPackages:
    vite: ^6.0.10 => 6.0.10
    vitest: ^3.0.2 => 3.0.2

Used Package Manager

npm

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[hi-ogawa]

This looks like a duplicate of #7070 (comment) though it's probably more complicated.

@emotion/xxx packages uses development and module conditions https://publint.dev/@emotion/[email protected], but Vitest 3 dropped both. I actually don't understand why this would break @emotion/xxx since they seems to be functional on plain Node, which doesn't have neither of development and module. https://stackblitz.com/edit/vitest-dev-vitest-whbrjxfd?file=repro.js

Nonetheless, adding resolve.conditions: ['node', 'development'] fixes the repro, so this will be probably fixed by #7301

[bmcallis]

This was fixed by 3.0.4. Thanks