Stuck on an issue?

I have this in my support/index.ts

my tsconfig.json looks like this:

{
  "compilerOptions": {
    "lib": [
      "dom",
      "es2015",
      "es5",
      "es6",
      "es2015"
    ],
    "target": "es5",
    "module": "commonjs",
    "noImplicitAny": false,
    "strictNullChecks": true,
    "noImplicitThis": true,
    "alwaysStrict": true,
  },
  "files": [
    "./support/index.d.ts"
  ]
}

I have this test:

describe("TypeScript", () => {
  it("checks shape of an object", () => {
    cy.visit('http://localhost:6001')
    cy.injectAxe();
  });
})

It fails with

ReferenceError: exports is not defined at axeFunction (eval at cy.window.then.window (http://localhost:6001/__cypress/tests?p=cypress/support/index.ts-538:111:12), :16:14) at eval (eval at cy.window.then.window (http://localhost:6001/__cypress/tests?p=cypress/support/index.ts-538:111:12), :15287:3) at eval ()

Why would this be?