2016-12-16 157 views
0

試圖爲我的redux reducer爲購物車創建一個單元測試。這是減速,該項目被添加到項目屬性:如何獲得減速機單元測試工作?

const initialState = { 
    items: [], 
    cartOpen: false, 
    newMonthlyCost: 0, 
    currentMonthlyCost: 0, 
    showNextButton: false, 
    orderConfirmed: false 
} 

const Cart = (state = initialState, action) => { 
    switch (action.type) { 
     case 'ADD_TO_CART': 
      return Object.assign({}, state, 
       { 
        items: [...state.items,action.data] 
       }); 

     default: 
      return state 
    } 
} 


export default Cart 

我釵單元測試是這樣的:

import reducer from './../../foss-frontend/app/reducers/cart.js' 
import {expect} from 'chai'; 

describe('cart reducer',() => { 

    it('should handle ADD_TO_CART',() => { 
     expect(
      reducer([], { 
       type: 'ADD_TO_CART', 
       data: { 
        id: 12, price: 2332 
       } 
      }) 
     ).to.deep.equal({items: [{id: 124, price: 2332}]}) 
    }) 
}) 

爲什麼會出現這種錯誤,以及如何解決這一問題?

錯誤:

 TypeError: Cannot convert undefined or null to object 
     at Function.from (native) 
     at _toConsumableArray (app\reducers\cart.js:7:182) 
+0

您的代碼看起來確定。我想錯誤是在你沒有發佈的部分。你能發佈減速器和測試的所有代碼嗎? –

+0

嗨Artem見上面 –

+0

'.to.deep.equal({items:{id:124,price:2332}})'應該是'.to.deep.equal({items:[{id:124,price: 2332}]})' –

回答

2

您撥打tetsts減速機採用空數組作爲國家

reducer([], {...}) 

所以state.items是不確定的。然後你嘗試解構它

items: [...state.items,action.data] 

並得到這個錯誤。

請檢查state.items存在 - 這樣的,比如

const Cart = (state = initialState, action) => { 
    switch (action.type) { 
     case 'ADD_TO_CART': 
      const { items=[] } = state; 
      return Object.assign({}, state, 
       { 
        items: [...items,action.data] 
       }); 

     default: 
      return state 
    } 
} 
+0

const {items = []} = state;做到了嗎? –

+0

簡短形式的const items = state.items;如果(!items)items = [];閱讀https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment –

+0

非常感謝,非常感謝 –

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