如何使用Jest和React测试功能

时间:2019-02-28 14:20:37

标签: javascript node.js reactjs jestjs

我对开玩笑和反应不熟悉,我需要为此功能编写单元测试,我确实试图理解文档,但是我在努力理解如何准确模拟此功能?

function desc(a, b, orderBy) {
if (b[orderBy] < a[orderBy]) {
    return -1;
}
if (b[orderBy] > a[orderBy]) {
    return 1;
}
return 0;
}

这也是我开玩笑的测试,该测试通过了,但是没有断言或行覆盖率

describe('Contract Table Ordering', () => {
 it('orders by desc', () => {
     contract.desc.mockImplementation(async () => { return (a, b, orderBy) 
=> (a[orderBy] > b[orderBy]) - (a[orderBy] <  b[orderBy]); });
 });
});

2 个答案:

答案 0 :(得分:0)

如果需要对对象列表/数组进行排序,则应执行以下操作:

请注意,您的js文件(sortFn.js)和单元测试文件(sortFn.js)应位于同一文件夹中。

//in your js (sortFn.js) file: 
const sortTable = orderBy => {
    return function(a, b) {
        if (a[orderBy] > b[orderBy]) {
            return -1;
        } else if (a[orderBy] < b[orderBy]) {
            return 1;
        }
        return 0;
    };
}
export default sortTable;


//In your unit-test file (sortFn.test.js): 
import sortTable from  './sortFn';

describe('Contract Table Ordering', () => {
const originalArray = [{name: 'ab', age: 19}, {name: 'xz', age: 26}, {name: 'ab', age: 14}, {name: 'cw', age: 22}];
const expectedArray = [{name: 'xz', age: 26}, {name: 'cw', age: 22}, {name: 'ab', age: 19},{name: 'ab', age: 14}];

it('orders by desc', () => {
   const sortResult =  originalArray.sort(sortTable('age'));
   expect(sortResult).toEqual(expectedArray);
});
});

答案 1 :(得分:0)

找到了一个解决方案,正如戴夫所说,我需要用数据调用它,然后检查它是否匹配,

 describe('Tests for the descendingOrderBy function', () => {
it('should reverse the full and part contracts', () => {
    const ordering = desc(fullObject, partContract, 'title');
    expect(ordering).toEqual(-1);
});