jest.unmock('../enum-member');

import {Stack} from '../../../stack';
import {VariableDeclaration} from '../../declarations/variable-declaration';
import {EnumMember} from '../enum-member';

describe('#emit()', () => {
  it('should return correctly', () => {
    const fn = (): number => 1;
    expect(new EnumMember({
      owned: new VariableDeclaration({name: 'x'}),
    }).emit(new Stack(), fn)).toMatchSnapshot();
  });
});

jest.unmock('../enum-member');

import {Stack} from '../../../stack';
import {VariableDeclaration} from '../../declarations/variable-declaration';
import {EnumMember} from '../enum-member';

describe('#_emit()', () => {
  it('should return correctly', () => {
    const fn = (): number => 1;
    expect(new EnumMember({
      owned: new VariableDeclaration({name: 'x'}),
    })._emit(new Stack(), fn)).toMatchSnapshot();
  });
});

--- 
+++ 
@@ -4,11 +4,11 @@
 import {VariableDeclaration} from '../../declarations/variable-declaration';
 import {EnumMember} from '../enum-member';
 
-describe('#_emit()', () => {
+describe('#emit()', () => {
   it('should return correctly', () => {
     const fn = (): number => 1;
     expect(new EnumMember({
       owned: new VariableDeclaration({name: 'x'}),
-    })._emit(new Stack(), fn)).toMatchSnapshot();
+    }).emit(new Stack(), fn)).toMatchSnapshot();
   });
 });
Update tests
use emit() instead of _emit()
