Lodash is undefined when testing a Svelte app with Jest

I'm trying to use Jest to test my Svelte project, and everything I've read says that I need to include svelte-jester to transform my Svelte code into something that Jest can process (CommonJS, I think?). This seems to work fine, except that I'm importing Lodash into some of my Svelte components but Jest, when running its tests, is reporting that Lodash is undefined. (In a browser environment, everything seems to be working as expected.)

To demonstrate the issue, I copied and slightly modified an example from the testing-library website:

// Comp.svelte<script>  import _ from 'lodash';  export let name</script><h1>Hello {_.toUpper(name)}!</h1>

and then my test file is

// tests/Comp.test.jsimport '@testing-library/jest-dom/extend-expect'import { render } from '@testing-library/svelte'import Comp from '../Comp'test('shows proper heading when rendered', () => {  const { getByText } = render(Comp, { name: 'World' })  expect(getByText('Hello WORLD!')).toBeInTheDocument()})

The relevant part of my package.json is the following, which I also got from the testing-library website.

{"devDependencies": {"@babel/core": "^7.12.16","@babel/preset-env": "^7.12.16","@rollup/plugin-commonjs": "^16.0.0","@rollup/plugin-node-resolve": "^10.0.0","@testing-library/jest-dom": "^5.11.9","@testing-library/svelte": "^3.0.3","babel-jest": "^26.6.3","jest": "^26.6.3","rollup": "^2.3.4","rollup-plugin-svelte": "^7.0.0","svelte": "^3.0.0","svelte-jester": "^1.3.0"  },"dependencies": {"lodash": "^4.17.20",  },"jest": {"transform": {"^.+\\.js$": "babel-jest","^.+\\.svelte$": ["svelte-jester", { "debug": true }]    },"moduleFileExtensions": ["js","svelte"    ],  }}

The test output indicates that, in the compiled version of Comp.svelte, Lodash is undefined:

    TypeError: Cannot read property 'toUpper' of undefined      5 | </script>      6 |> 7 | <h1>Hello {_.toUpper(name)}!</h1>        |              ^      at create_fragment (src/Comp.svelte:7:14)      at init (node_modules/svelte/internal/index.js:1489:37)      at new Comp (src/Comp.svelte:83:3)      at render (node_modules/@testing-library/svelte/dist/pure.js:81:21)      at Object.<anonymous> (src/tests/Comp.spec.js:9:25)

The compiled version of the component seems to indicate that, at a minimum, Lodash is being require-d into the build.

/* Comp.svelte generated by Svelte v3.31.0 */"use strict";const { SvelteComponentDev, add_location, append_dev, detach_dev, dispatch_dev, element, flush, init, insert_dev, noop, safe_not_equal, set_data_dev, text, validate_slots } = require("svelte/internal");const { default: _ } = require("lodash");const file = "Comp.svelte";// etc.

Can someone please tell me what I need to do to get Lodash to be properly exported and/or required into the build for a Jest test? Thank you very much.