Branches that don't exist get reported as missing

[throoze]

I'm getting a coverage report with missing coverage for branches that aren't there (I think):

Here's the test:

/**
 * @jest-environment jsdom
 */
import React from 'react';
import {mount} from 'enzyme';
import {StyledSnackbar, StyledText} from './snackbar.style';

jest.mock('react-native-paper', () => ({
  Colors: jest.requireActual('react-native-paper').Colors,
  Snackbar: () => 'Snackbar',
}));

describe('snackbar.style', () => {
  describe('StyledSnackbar', () => {
    test.each`
      variantName  | variant
      ${'error'}   | ${'error'}
      ${'warning'} | ${'warn'}
      ${'info'}    | ${'info'}
      ${'default'} | ${'default'}
    `('should match snapshot for variant $variantName', ({variant}) => {
      const component = mount(<StyledSnackbar variant={variant} />);
      expect(component.exists()).toBeTruthy();
      expect(component).toMatchSnapshot();
    });
  });
  describe('StyledText', () => {
    test.each`
      variantName  | variant
      ${'error'}   | ${'error'}
      ${'warning'} | ${'warn'}
      ${'info'}    | ${'info'}
      ${'default'} | ${'default'}
    `('should match snapshot for variant $variantName', ({variant}) => {
      const component = mount(<StyledText variant={variant} />);
      expect(component.exists()).toBeTruthy();
      expect(component).toMatchSnapshot();
    });
  });
});

Another example:

And its test:

import React from 'react';
import {shallow} from 'enzyme';
import {Snackbar} from './snackbar';
import {StyledSnackbar, StyledText} from './snackbar.style';

describe('Snackbar', () => {
  it('should render correctly with default props', () => {
    const component = shallow(<Snackbar>Children</Snackbar>);
    expect(component.exists()).toBeTruthy();
    expect(component.text()).toEqual('Children');
    expect(component.find(StyledSnackbar).prop('variant')).toEqual('default');
    expect(component.find(StyledText).prop('variant')).toEqual('default');
  });

  test.each`
    variantName  | variant
    ${'error'}   | ${'error'}
    ${'warning'} | ${'warn'}
    ${'info'}    | ${'info'}
    ${'default'} | ${'default'}
  `('should render correctly with variant $variantName', ({variant}) => {
    const component = shallow(<Snackbar {...{variant}}>Children</Snackbar>);
    expect(component.exists()).toBeTruthy();
    expect(component.text()).toEqual('Children');
    expect(component.find(StyledSnackbar).prop('variant')).toEqual(variant);
    expect(component.find(StyledText).prop('variant')).toEqual(variant);
  });
});

I haven't been able to test anything with toHaveStyleRule and jest-styled-components because of some issue with my configuration and/or mismatching versions, but still i thing that file should be totally covered

Here's my configuration in case I'm missing something:

package.json:

{
  "dependencies": {
    "@react-native-community/masked-view": "^0.1.10",
    "@react-native-firebase/app": "^10.8.0",
    "@react-native-firebase/auth": "^10.8.0",
    "@react-navigation/drawer": "^5.12.3",
    "@react-navigation/native": "^5.9.2",
    "@react-navigation/stack": "^5.14.2",
    "formik": "^2.2.6",
    "react": "16.13.1",
    "react-native": "0.63.4",
    "react-native-gesture-handler": "^1.10.1",
    "react-native-paper": "^4.7.1",
    "react-native-reanimated": "^1.13.2",
    "react-native-safe-area-context": "^3.1.9",
    "react-native-screens": "^2.17.1",
    "react-native-svg": "^12.1.0",
    "react-native-vector-icons": "^8.0.0",
    "styled-components": "^5.2.1",
    "yup": "^0.32.9"
  },
  "devDependencies": {
    "@babel/core": "^7.8.4",
    "@babel/runtime": "^7.8.4",
    "@react-native-community/eslint-config": "^1.1.0",
    "babel-jest": "^25.1.0",
    "enzyme": "^3.11.0",
    "enzyme-adapter-react-16": "^1.15.6",
    "enzyme-to-json": "^3.6.1",
    "eslint": "^6.5.1",
    "jest": "^25.1.0",
    "jest-environment-enzyme": "^7.1.2",
    "jest-enzyme": "^7.1.2",
    "jest-styled-components": "^7.0.3",
    "metro-react-native-babel-preset": "^0.59.0",
    "react-dom": "16.13.1",
    "react-native-svg-transformer": "^0.14.3",
    "react-test-renderer": "16.13.1"
  },
  "jest": {
    "preset": "react-native",
    "transform": {
      "^.+\\.js$": "<rootDir>/node_modules/react-native/jest/preprocessor.js"
    },
    "testEnvironment": "enzyme",
    "testEnvironmentOptions": {
      "enzymeAdapter": "react16"
    },
    "collectCoverage": true,
    "collectCoverageFrom": [
      "<rootDir>/src/**/**.js"
    ],
    "coverageThreshold": {
      "global": {
        "branches": 90,
        "functions": 90,
        "lines": 90,
        "statements": 90
      }
    },
    "setupFilesAfterEnv": [
      "jest-enzyme",
      "<rootDir>/jest.setup.js",
      "<rootDir>/node_modules/react-native-gesture-handler/jestSetup.js"
    ],
    "transformIgnorePatterns": [
      "node_modules/(?!(jest-)?react-native|@?react-navigation)"
    ]
  },
  "resolutions": {
    "styled-components": "^5"
  }
}

babel.config.js:

module.exports = {
  presets: ['module:metro-react-native-babel-preset'],
  env: {
    production: {
      plugins: ['react-native-paper/babel'],
    },
  },
};

jest.setup.js:

import 'react-native-gesture-handler/jestSetup';
import 'jest-styled-components/native'; // doesn't work!
import Enzyme from 'enzyme';
import Adapter from 'enzyme-adapter-react-16';

const {JSDOM} = require('jsdom');

const jsdom = new JSDOM();
const {window} = jsdom;

function copyProps(src, target) {
  const props = Object.getOwnPropertyNames(src)
    .filter((prop) => typeof target[prop] === 'undefined')
    .map((prop) => Object.getOwnPropertyDescriptor(src, prop));
  Object.defineProperties(target, props);
}

global.window = window;
global.document = window.document;
global.navigator = {
  userAgent: 'node.js',
};

copyProps(window, global);

jest.mock('react-native-reanimated', () => {
  const Reanimated = require('react-native-reanimated/mock');

  // The mock for `call` immediately calls the callback which is incorrect
  // So we override it with a no-op
  Reanimated.default.call = () => {};

  return Reanimated;
});
import {NativeModules} from 'react-native';

NativeModules.RNGestureHandlerModule = {
  attachGestureHandler: jest.fn(),
  createGestureHandler: jest.fn(),
  dropGestureHandler: jest.fn(),
  updateGestureHandler: jest.fn(),
  State: {},
  Directions: {},
};
NativeModules.ImagePickerManager = {
  showImagePicker: jest.fn(),
};
NativeModules.Linking = {
  canOpenUrl: jest.fn().mockResolvedValue(true),
  openUrl: jest.fn().mockResolvedValue(true),
};
NativeModules.Platform = {
  OS: 'iOS',
};

jest.mock('react-native/Libraries/Animated/src/NativeAnimatedHelper');
jest.mock('react-native/Libraries/Animated/src/animations/TimingAnimation');

Enzyme.configure({adapter: new Adapter()});

Any help would be appreciated! Please let me know if I'm wrong and why are there any branches there... Thanks a lot!