Cypress component test to assert function called with deep nested object value

When doing cypress component test on a form, I came across an issue that the onSubmit function is called with a deep nested object. The object looks something like this:

{
  relationshipPartner: {
    id: string; 
    email: string; 
    info: { firstName: string; lastName:string; }
  };
  ...moreProperties,
}

I wanted to assert that onSubmit function is called with the correct relationship partner email. It was really hard to use .toEqual(). When I had the order of the properties wrong it returns false and I always had to write out the whole object even when I only care about the relationship partner email.

It was quite a struggle but in the end I had a solution looks like this:

it("should submit with relationship partner", () => {
    const onSubmit = cy.stub().as("onSubmit");
    mount(
      <AddCompanyRelationshipPartner
        onSubmit={onSubmit}
      />
    );
    cy.findByRole("button", { name: /Update Relationship Partner/i }).click();
    cy.findAllByLabelText(/relationship partner/i)
      .first()
      .type("ellen{enter}");
    cy.findByRole("button", { name: /Save/i }).click();
    cy.get("@onSubmit").should((i) => {
      const spy = i["getCalls"]();
      const { args } = spy[0];
expect(args[0].relationshipPartner.email).to.equal("ellen@nexl.io");
    });
  });

Hope this helps =)