Question

这是我的项目：

MockTestDependency.js：

export default class MockTestDependency {
    testAction1() {
        return 'testAction1'
    }

    testAction2() {
        return 'testAction2'
    }
}

MockTest.test.js：

jest.mock('./MockTestDependency')

import MockTestDependency from './MockTestDependency'

beforeAll(() => {
    MockTestDependency.mockImplementation(() => {
            return {
                testAction1: () => {return 'mocked1'},
            }
        }
    )
})

describe('mock test 3', () => {
    it('first case', () => {
        let mockTestDependency = new MockTestDependency()
        expect(mockTestDependency.testAction1()).toBe('mocked1')
        expect(mockTestDependency.testAction2()).toBe('testAction2')
    })
})

运行jest命令后发生错误：

TypeError: mockTestDependency.testAction2 is not a function

那么，如何在不影响函数testAction1的情况下模拟函数testAction2？

任何帮助都将不胜感激。

Answer 1

看一下jest.spyOn()函数，它允许只模拟选择的方法。当您使用jest.mock('./MockTestDependency')时，它会将模块中的所有方法模拟为jest.fn()

import MockTestDependency from './MockTestDependency'

beforeAll(() => {
    jest.spyOn(MockTestDependency, 'testAction1').mockImplementation(() => 'mocked1');
})

describe('mock test 3', () => {
    it('first case', () => {
        let mockTestDependency = new MockTestDependency()
        expect(mockTestDependency.testAction1()).toBe('mocked1')
        expect(mockTestDependency.testAction2()).toBe('testAction2')
    })
})

如何模拟特定功能而不影响同一个ES6类中的其他功能？

1 个答案: