Can't test React component method, why?

Question

JavaScript

Hello.
Unable to test methods in class react component. Here is the method:

testSum(a, b) {
    return a + b;

In tests I write the following:

const wrapper = shallow(<МойКомпонент/>);
 console.log(wrapper.instance().testSum(2,4).toBe(6));

but it draws an error that they say wrapper.instance(...).testSum is not a function
to the wrapper.instance() console, and there, apart from the wired React methods, nothing, not one of my methods, but only

Connect {
      props: {},
      context: {},
      refs: {},
      updater:
       Updater {
         _renderer:
          ReactShallowRenderer {
            _context: {},
            _element: [Object],
            _instance: [Circular],
            _newState: null,
            _rendered: [Object],
            _rendering: false,
            _forcedUpdate: false,
            _updater: [Circular],
            _dispatcher: [Object],
            _workInProgressHook: null,
            _firstWorkInProgressHook: null,
            _isReRender: false,
            _didScheduleRenderPhaseUpdate: false,
            _renderPhaseUpdates: null,
            _numberOfReRenders: 0 },
         _callbacks: [] },
      selectDerivedProps: [Function: selectDerivedProps],
      selectChildElement: [Function: selectChildElement],
      indirectRenderWrappedComponent: [Function: bound indirectRenderWrappedComponent],
      state: null,
      setState: [Function] }

what am I doing wrong, I want to test methods on components?

Answer 1

Connect {
      props: {},
      context: {},

The word Connect at the very beginning, as it were, hints that the component is apparently wrapped in connect and naturally there will be no testSum method there.