[英]How to test redux saga with jest?
react,react-redux / saga和jest中的新功能
考慮:
-----組分()----
componentDidMount() {
this.props.actions.initTodos(
axios,
ajaxURLConstants.WP_GET_TODOS,
appStateActions.setAppInIdle,
appStateActions.setAppInProcessing,
todosActions.todosInitialized
);
}
因此,當我的TodoApp組件掛載時,它將分派INIT_TODOS操作,然后我的根傳奇正在偵聽該事件 ,當它被捕獲時,將產生適當的worker傳奇以采取相應的行動。
-----相應的工人傳奇-----
export function* initTodosSaga( action ) {
try {
yield put( action.setAppInProcessing() );
let response = yield call( action.axios.get , action.WP_GET_TODOS );
if ( response.data.status === "success" )
yield put( action.todosInitialized( response.data.todos ) );
else {
console.log( response );
alert( response.data.error_msg );
}
} catch ( error ) {
console.log( "error" , error );
alert( "Failed to load initial data" );
}
yield put( action.setAppInIdle() );
}
-----到目前為止的測試-----
import todos from "../../__fixtures__/todos";
import { initTodosSaga } from "../todosSaga";
test( "saga test" , () => {
let response = {
status : "success",
todos
},
action = {
axios : {
get : function() {
return new Promise( ( resolve , reject ) => {
resolve( response );
} );
}
},
WP_GET_TODOS : "dummy url",
setAppInIdle : jest.fn(),
setAppInProcessing : jest.fn(),
todosInitialized : jest.fn()
};
let initTodosSagaGen = initTodosSaga( action );
initTodosSagaGen.next();
expect( action.setAppInIdle ).toHaveBeenCalled();
} );
-----測試結果-----
所以重要的是
console.error node_modules \\ redux-saga \\ lib \\ internal \\ utils.js:240
在check put(action)時未捕獲:參數action未定義
但是我有console.log我在worker saga中通過測試的動作,並且確實不是不確定的
我想念什么?
提前致謝。
----------更新------------
好的,請注意,在上面這行代碼中有抱怨
yield put( action.setAppInIdle() );
這是在try catch塊之外,因此我進行了一些更改
1.)我將代碼移到try catch塊內的上方,就在
if ( response.data.status === "success" )
請檢查上面的initTodosSaga代碼
然后在我的傳奇測試中,我測試
expect( action.setAppInProcessing ).toHaveBeenCalled();
代替setAppInIdle間諜函數
這是測試結果
所以測試通過了! 但它仍然抱怨動作未定義
現在有趣的是,如果在我的傳奇測試中,如果我現在對此進行測試
expect( action.setAppInProcessing ).toHaveBeenCalled();
expect( action.setAppInIdle ).toHaveBeenCalled();
這是結果
所以現在它仍然抱怨該操作仍未定義(我的屏幕截圖中未包含該操作,但與上面相同)
再加上第二個斷言,我沒有調用setAppInIdle間諜函數,但是setAppInProcessing確實通過了!
我希望此附加信息有助於解決此問題。
沒有外部庫的幫助,似乎很難測試redux saga
對我來說我使用了https://github.com/jfairbank/redux-saga-test-plan
這個圖書館很好。
所以這是我的測試
--------------------測試1 ---------------------
因此,對於此測試,我通過了動作有效負載,而傳奇幾乎是它運行所需要的一切。 axios,動作創建者功能等,更像是遵循依賴注入的原理,因此易於測試。
----- TodoApp組件-----
componentDidMount() {
this.props.actions.initTodos(
axios,
ajaxURLConstants.WP_GET_TODOS,
appStateActions.setAppInIdle,
appStateActions.setAppInProcessing,
todosActions.todosInitialized,
todosActions.todosFailedInit
);
}
因此,當該組件安裝好后,它會觸發我的根傳奇偵聽並捕獲的動作,然后生成適當的worker傳奇以采取相應行動
再次注意,我傳遞了所有必要的數據,這些信息需要工人傳奇才能在動作有效負載上正常運行。
----- initTodoSaga(工人傳奇)-----
export function* initTodosSaga( action ) {
try {
yield put( action.setAppInProcessing() );
let response = yield call( action.axios.get , action.WP_GET_TODOS );
if ( response.data.status === "success" )
yield put( action.todosInitialized( response.data.todos ) );
else {
console.log( response );
alert( response.data.error_msg );
yield put( action.todosFailedInit( response ) );
}
} catch ( error ) {
console.log( "error" , error );
alert( "Failed to load initial data" );
yield put( action.todosFailedInit( error ) );
}
yield put( action.setAppInIdle() );
}
-----佐賀測試-----
import { expectSaga } from "redux-saga-test-plan";
import { initTodosSaga } from "../todosSaga";
test( "should initialize the ToDos state via the initTodoSaga" , () => {
let response = {
data : {
status : "success",
todos
}
},
action = {
axios : {
get : function() {
return new Promise( ( resolve , reject ) => {
resolve( response );
} );
}
},
WP_GET_TODOS : "dummy url",
setAppInIdle : appStateActions.setAppInIdle,
setAppInProcessing : appStateActions.setAppInProcessing,
todosInitialized : todosStateActions.todosInitialized,
todosFailedInit : todosStateActions.todosFailedInit
};
// This is the important bit
// These are the assertions
// Basically saying that the actions below inside the put should be dispatched when this saga is executed
return expectSaga( initTodosSaga , action )
.put( appStateActions.setAppInProcessing() )
.put( todosStateActions.todosInitialized( todos ) )
.put( appStateActions.setAppInIdle() )
.run();
} );
我的測試通過了! :)現在向您顯示測試失敗時的錯誤消息,我將在initTodosSaga中注釋掉這一行代碼
yield put( action.setAppInIdle() );
所以現在斷言
.put( appStateActions.setAppInIdle() )
現在應該失敗
因此它輸出的期望值未得到滿足 ,因為我們預期要執行的操作沒有
--------------------測試2 --------------------
現在,此測試是一個傳奇,它導入了需要操作的某些東西,這與我的第一個測試不同,我在動作有效負載中輸入了axios,動作創建者
這個傳奇故事導入了axios,它需要操作的動作創建者
值得慶幸的是, Redux Saga測試計划具有一些輔助功能,可將虛假數據“饋送”到Saga
我將只跳過觸發根傳奇正在監聽的動作的組件,這並不重要,我將直接粘貼傳奇和saga測試
---- addTodoSaga ----
/** global ajaxurl */
import axios from "axios";
import { call , put } from "redux-saga/effects";
import * as appStateActions from "../actions/appStateActions";
import * as todosActions from "../actions/todosActions";
export function* addTodoSaga( action ) {
try {
yield put( appStateActions.setAppInProcessing() );
let formData = new FormData;
formData.append( "todo" , JSON.stringify( action.todo ) );
let response = yield call( axios.post , ajaxurl + "?action=wptd_add_todo" , formData );
if ( response.data.status === "success" ) {
yield put( todosActions.todoAdded( action.todo ) );
action.successCallback();
} else {
console.log( response );
alert( response.data.error_msg );
}
} catch ( error ) {
console.log( error );
alert( "Failed to add new todo" );
}
yield put( appStateActions.setAppInIdle() );
}
- - -考試 - - -
import axios from "axios";
import { expectSaga } from "redux-saga-test-plan";
import * as matchers from "redux-saga-test-plan/matchers";
import * as appStateActions from "../../actions/appStateActions";
import * as todosStateActions from "../../actions/todosActions";
import { addTodoSaga } from "../todosSaga";
test( "should dispatch TODO_ADDED action when adding new todo is successful" , () => {
let response = {
data : { status : "success" }
},
todo = {
id : 1,
completed : false,
title : "Browse 9gag tonight"
},
action = {
todo,
successCallback : jest.fn()
};
// Here are the assertions
return expectSaga( addTodoSaga , action )
.provide( [
[ matchers.call.fn( axios.post ) , response ]
] )
.put( appStateActions.setAppInProcessing() )
.put( todosStateActions.todoAdded( todo ) )
.put( appStateActions.setAppInIdle() )
.run();
} );
因此,provide函數允許您模擬函數調用,同時提供應返回的偽數據
就是這樣,我現在可以測試我的sagas! 好極了!
還有一件事,當我為自己的傳奇運行測試時,導致執行帶有警報代碼的代碼
例如
alert( "Earth is not flat!" );
我在控制台上得到了
Error: Not implemented: window.alert
以及它下面的一堆堆棧跟蹤信息,可能是因為警報對象不在節點上嗎? 我該如何隱藏呢? 如果您有答案,請添加評論。
我希望這可以幫助任何人
這是您的測試的工作版本:
import todos from '../../__fixtures__/todos';
import { initTodosSaga } from '../todosSaga';
import { put, call } from 'redux-saga/effects';
test('saga test', () => {
const response = {
data: {
status: 'success',
todos
}
};
const action = {
axios: {
get() {}
},
WP_GET_TODOS: 'dummy url',
setAppInIdle: jest.fn().mockReturnValue({ type: 'setAppInIdle' }),
setAppInProcessing: jest.fn().mockReturnValue({ type: 'setAppInProcessing' }),
todosInitialized: jest.fn().mockReturnValue({ type: 'todosInitialized' })
};
let result;
const initTodosSagaGen = initTodosSaga(action);
result = initTodosSagaGen.next();
expect(result.value).toEqual(put(action.setAppInProcessing()));
expect(action.setAppInProcessing).toHaveBeenCalled();
result = initTodosSagaGen.next();
expect(result.value).toEqual(call(action.axios.get, action.WP_GET_TODOS));
result = initTodosSagaGen.next(response);
expect(action.todosInitialized).toHaveBeenCalled();
expect(result.value).toEqual(put(action.todosInitialized(response.data.todos)));
result = initTodosSagaGen.next();
expect(action.setAppInIdle).toHaveBeenCalled();
expect(result.value).toEqual(put(action.setAppInIdle()));
});
一些注意事項:
expect
語句,我正在將生成器的產量與期望生成器執行的操作進行比較(即執行put
和call
語句) data
屬性
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