I keep getting "localStorage is not defined" in Jest tests which makes sense but what are my options? Hitting brick walls.
Great solution from #chiedo
However, we use ES2015 syntax and I felt it was a little cleaner to write it this way.
class LocalStorageMock {
constructor() {
this.store = {};
}
clear() {
this.store = {};
}
getItem(key) {
return this.store[key] || null;
}
setItem(key, value) {
this.store[key] = String(value);
}
removeItem(key) {
delete this.store[key];
}
}
global.localStorage = new LocalStorageMock;
Figured it out with help from this: https://groups.google.com/forum/#!topic/jestjs/9EPhuNWVYTg
Setup a file with the following contents:
var localStorageMock = (function() {
var store = {};
return {
getItem: function(key) {
return store[key];
},
setItem: function(key, value) {
store[key] = value.toString();
},
clear: function() {
store = {};
},
removeItem: function(key) {
delete store[key];
}
};
})();
Object.defineProperty(window, 'localStorage', { value: localStorageMock });
Then you add the following line to your package.json under your Jest configs
"setupTestFrameworkScriptFile":"PATH_TO_YOUR_FILE",
Answer:
Currently (Jul '22) localStorage can not be mocked or spied on by jest as you usually would, and as outlined in the create-react-app docs. This is due to changes made in jsdom. You can read about it in the jest and jsdom issue trackers.
As a workaround, you can spy on the prototype instead:
// does not work:
jest.spyOn(localStorage, "setItem");
localStorage.setItem = jest.fn();
// either of these lines will work, different syntax that does the same thing:
jest.spyOn(Storage.prototype, 'setItem');
Storage.prototype.setItem = jest.fn();
// assertions as usual:
expect(localStorage.setItem).toHaveBeenCalled();
A note on spying on the prototype:
Spying on an instance gives you the ability to observe and mock behaviour for a specific object.
Spying on the prototype, on the other hand, will observe/manipulate every instance of that class all at once. Unless you have a special usecase, this is probably not what you want.
However, in this case it makes no difference, because there only exists a single instance of localStorage.
If using create-react-app, there is a simpler and straightforward solution explained in the documentation.
Create src/setupTests.js and put this in it :
const localStorageMock = {
getItem: jest.fn(),
setItem: jest.fn(),
clear: jest.fn()
};
global.localStorage = localStorageMock;
Tom Mertz contribution in a comment below :
You can then test that your localStorageMock's functions are used by doing something like
expect(localStorage.getItem).toBeCalledWith('token')
// or
expect(localStorage.getItem.mock.calls.length).toBe(1)
inside of your tests if you wanted to make sure it was called. Check out https://facebook.github.io/jest/docs/en/mock-functions.html
Unfortunately, the solutions that I've found here didn't work for me.
So I was looking at Jest GitHub issues and found this thread
The most upvoted solutions were these ones:
const spy = jest.spyOn(Storage.prototype, 'setItem');
// or
Storage.prototype.getItem = jest.fn(() => 'bla');
A better alternative which handles undefined values (it doesn't have toString()) and returns null if value doesn't exist. Tested this with react v15, redux and redux-auth-wrapper
class LocalStorageMock {
constructor() {
this.store = {}
}
clear() {
this.store = {}
}
getItem(key) {
return this.store[key] || null
}
setItem(key, value) {
this.store[key] = value
}
removeItem(key) {
delete this.store[key]
}
}
global.localStorage = new LocalStorageMock
or you just take a mock package like this:
https://www.npmjs.com/package/jest-localstorage-mock
it handles not only the storage functionality but also allows you test if the store was actually called.
If you are looking for a mock and not a stub, here is the solution I use:
export const localStorageMock = {
getItem: jest.fn().mockImplementation(key => localStorageItems[key]),
setItem: jest.fn().mockImplementation((key, value) => {
localStorageItems[key] = value;
}),
clear: jest.fn().mockImplementation(() => {
localStorageItems = {};
}),
removeItem: jest.fn().mockImplementation((key) => {
localStorageItems[key] = undefined;
}),
};
export let localStorageItems = {}; // eslint-disable-line import/no-mutable-exports
I export the storage items for easy initialization. I.E. I can easily set it to an object
In the newer versions of Jest + JSDom it is not possible to set this, but the localstorage is already available and you can spy on it it like so:
const setItemSpy = jest.spyOn(Object.getPrototypeOf(window.localStorage), 'setItem');
For Jest, React & TypeScript users:
I created a mockLocalStorage.ts
export const mockLocalStorage = () => {
const setItemMock = jest.fn();
const getItemMock = jest.fn();
beforeEach(() => {
Storage.prototype.setItem = setItemMock;
Storage.prototype.getItem = getItemMock;
});
afterEach(() => {
setItemMock.mockRestore();
getItemMock.mockRestore();
});
return { setItemMock, getItemMock };
};
My component:
export const Component = () => {
const foo = localStorage.getItem('foo')
localStorage.setItem('bar', 'true')
return <h1>{foo}</h1>
}
then in my tests I use it like so:
import React from 'react';
import { mockLocalStorage } from '../../test-utils';
import { Component } from './Component';
const { getItemMock, setItemMock } = mockLocalStorage();
it('fetches something from localStorage', () => {
getItemMock.mockReturnValue('bar');
render(<Component />);
expect(getItemMock).toHaveBeenCalled();
expect(getByText(/bar/i)).toBeInTheDocument()
});
it('expects something to be set in localStorage' () => {
const value = "true"
const key = "bar"
render(<Component />);
expect(setItemMock).toHaveBeenCalledWith(key, value);
}
I found this solution from github
var localStorageMock = (function() {
var store = {};
return {
getItem: function(key) {
return store[key] || null;
},
setItem: function(key, value) {
store[key] = value.toString();
},
clear: function() {
store = {};
}
};
})();
Object.defineProperty(window, 'localStorage', {
value: localStorageMock
});
You can insert this code in your setupTests and it should work fine.
I tested it in a project with typesctipt.
A bit more elegant solution using TypeScript and Jest.
interface Spies {
[key: string]: jest.SpyInstance
}
describe('→ Local storage', () => {
const spies: Spies = {}
beforeEach(() => {
['setItem', 'getItem', 'clear'].forEach((fn: string) => {
const mock = jest.fn(localStorage[fn])
spies[fn] = jest.spyOn(Storage.prototype, fn).mockImplementation(mock)
})
})
afterEach(() => {
Object.keys(spies).forEach((key: string) => spies[key].mockRestore())
})
test('→ setItem ...', async () => {
localStorage.setItem( 'foo', 'bar' )
expect(localStorage.getItem('foo')).toEqual('bar')
expect(spies.setItem).toHaveBeenCalledTimes(1)
})
})
You can use this approach, to avoid mocking.
Storage.prototype.getItem = jest.fn(() => expectedPayload);
Object.defineProperty(window, "localStorage", {
value: {
getItem: jest.fn(),
setItem: jest.fn(),
removeItem: jest.fn(),
},
});
or
jest.spyOn(Object.getPrototypeOf(localStorage), "getItem");
jest.spyOn(Object.getPrototypeOf(localStorage), "setItem");
As #ck4 suggested documentation has clear explanation for using localStorage in jest. However the mock functions were failing to execute any of the localStorage methods.
Below is the detailed example of my react component which make uses of abstract methods for writing and reading data,
//file: storage.js
const key = 'ABC';
export function readFromStore (){
return JSON.parse(localStorage.getItem(key));
}
export function saveToStore (value) {
localStorage.setItem(key, JSON.stringify(value));
}
export default { readFromStore, saveToStore };
Error:
TypeError: _setupLocalStorage2.default.setItem is not a function
Fix:
Add below mock function for jest (path: .jest/mocks/setUpStore.js )
let mockStorage = {};
module.exports = window.localStorage = {
setItem: (key, val) => Object.assign(mockStorage, {[key]: val}),
getItem: (key) => mockStorage[key],
clear: () => mockStorage = {}
};
Snippet is referenced from here
To do the same in the Typescript, do the following:
Setup a file with the following contents:
let localStorageMock = (function() {
let store = new Map()
return {
getItem(key: string):string {
return store.get(key);
},
setItem: function(key: string, value: string) {
store.set(key, value);
},
clear: function() {
store = new Map();
},
removeItem: function(key: string) {
store.delete(key)
}
};
})();
Object.defineProperty(window, 'localStorage', { value: localStorageMock });
Then you add the following line to your package.json under your Jest configs
"setupTestFrameworkScriptFile":"PATH_TO_YOUR_FILE",
Or you import this file in your test case where you want to mock the localstorage.
describe('getToken', () => {
const Auth = new AuthService();
const token = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VybmFtZSI6Ik1yIEpvc2VwaCIsImlkIjoiNWQwYjk1Mzg2NTVhOTQ0ZjA0NjE5ZTA5IiwiZW1haWwiOiJ0cmV2X2pvc0Bob3RtYWlsLmNvbSIsInByb2ZpbGVVc2VybmFtZSI6Ii9tcmpvc2VwaCIsInByb2ZpbGVJbWFnZSI6Ii9Eb3Nlbi10LUdpci1sb29rLWN1dGUtbnVrZWNhdDMxNnMtMzExNzAwNDYtMTI4MC04MDAuanBnIiwiaWF0IjoxNTYyMzE4NDA0LCJleHAiOjE1OTM4NzYwMDR9.YwU15SqHMh1nO51eSa0YsOK-YLlaCx6ijceOKhZfQZc';
beforeEach(() => {
global.localStorage = jest.fn().mockImplementation(() => {
return {
getItem: jest.fn().mockReturnValue(token)
}
});
});
it('should get the token from localStorage', () => {
const result = Auth.getToken();
expect(result).toEqual(token);
});
});
Create a mock and add it to the global object
At least as of now, localStorage can be spied on easily on your jest tests, for example:
const spyRemoveItem = jest.spyOn(window.localStorage, 'removeItem')
And that's it. You can use your spy as you are used to.
This worked for me and just one code line
const setItem = jest.spyOn(Object.getPrototypeOf(localStorage), 'setItem');
2021, typescript
class LocalStorageMock {
store: { [k: string]: string };
length: number;
constructor() {
this.store = {};
this.length = 0;
}
/**
* #see https://developer.mozilla.org/en-US/docs/Web/API/Storage/key
* #returns
*/
key = (idx: number): string => {
const values = Object.values(this.store);
return values[idx];
};
clear() {
this.store = {};
}
getItem(key: string) {
return this.store[key] || null;
}
setItem(key: string, value: string) {
this.store[key] = String(value);
}
removeItem(key: string) {
delete this.store[key];
}
}
export default LocalStorageMock;
you can then use it with
global.localStorage = new LocalStorageMock();
Riffed off some other answers here to solve it for a project with Typescript. I created a LocalStorageMock like this:
export class LocalStorageMock {
private store = {}
clear() {
this.store = {}
}
getItem(key: string) {
return this.store[key] || null
}
setItem(key: string, value: string) {
this.store[key] = value
}
removeItem(key: string) {
delete this.store[key]
}
}
Then I created a LocalStorageWrapper class that I use for all access to local storage in the app instead of directly accessing the global local storage variable. Made it easy to set the mock in the wrapper for tests.
As mentioned in a comment by Niket Pathak,
starting jest#24 / jsdom#11.12.0 and above, localStorage is mocked automatically.
An update for 2022.
Jest#24+ has ability to mock local storage automatically. However, the dependency needed no longer ships with it by default.
npm i -D jest-environment-jsdom
You also need to change your Jest test mode:
// jest.config.cjs
module.exports = {
...
testEnvironment: "jsdom",
...
};
Now localStorage will already be mocked for you.
Example:
// myStore.js
const saveLocally = (key, value) => {
localStorage.setItem(key, value)
};
Test:
// myStore.spec.ts
import { saveLocally } from "./myStore.js"
it("saves key-value pair", () => {
let key = "myKey";
let value = "myValue";
expect(localStorage.getItem(key)).toBe(null);
saveLocally(key, value);
expect(localStorage.getItem(key)).toBe(value);
};
The following solution is compatible for testing with stricter TypeScript, ESLint, TSLint, and Prettier config: { "proseWrap": "always", "semi": false, "singleQuote": true, "trailingComma": "es5" }:
class LocalStorageMock {
public store: {
[key: string]: string
}
constructor() {
this.store = {}
}
public clear() {
this.store = {}
}
public getItem(key: string) {
return this.store[key] || undefined
}
public setItem(key: string, value: string) {
this.store[key] = value.toString()
}
public removeItem(key: string) {
delete this.store[key]
}
}
/* tslint:disable-next-line:no-any */
;(global as any).localStorage = new LocalStorageMock()
HT/ https://stackoverflow.com/a/51583401/101290 for how to update global.localStorage
There is no need to mock localStorage - just use the jsdom environment so that your tests run in browser-like conditions.
In your jest.config.js,
module.exports = {
// ...
testEnvironment: "jsdom"
}
none of the answers above worked for me. So after some digging this is what I got to work. Credit goes to a few sources and other answers as well.
https://www.codeblocq.com/2021/01/Jest-Mock-Local-Storage/
https://github.com/facebook/jest/issues/6798#issuecomment-440988627
https://gist.github.com/mayank23/7b994385eb030f1efb7075c4f1f6ac4c
https://github.com/facebook/jest/issues/6798#issuecomment-514266034
My full gist: https://gist.github.com/ar-to/01fa07f2c03e7c1b2cfe6b8c612d4c6b
/**
* Build Local Storage object
* #see https://www.codeblocq.com/2021/01/Jest-Mock-Local-Storage/ for source
* #see https://stackoverflow.com/a/32911774/9270352 for source
* #returns
*/
export const fakeLocalStorage = () => {
let store: { [key: string]: string } = {}
return {
getItem: function (key: string) {
return store[key] || null
},
setItem: function (key: string, value: string) {
store[key] = value.toString()
},
removeItem: function (key: string) {
delete store[key]
},
clear: function () {
store = {}
},
}
}
/**
* Mock window properties for testing
* #see https://gist.github.com/mayank23/7b994385eb030f1efb7075c4f1f6ac4c for source
* #see https://github.com/facebook/jest/issues/6798#issuecomment-514266034 for sample implementation
* #see https://developer.mozilla.org/en-US/docs/Web/API/Window#properties for window properties
* #param { string } property window property string but set to any due to some warnings
* #param { Object } value for property
*
* #example
*
* const testLS = {
* id: 5,
* name: 'My Test',
* }
* mockWindowProperty('localStorage', fakeLocalStorage())
* window.localStorage.setItem('currentPage', JSON.stringify(testLS))
*
*/
const mockWindowProperty = (property: string | any, value: any) => {
const { [property]: originalProperty } = window
delete window[property]
beforeAll(() => {
Object.defineProperty(window, property, {
configurable: true,
writable: true,
value,
})
})
afterAll(() => {
window[property] = originalProperty
})
}
export default mockWindowProperty
In my case, I needed to set the localStorage value before I check it.
So what I did is
const data = { .......}
const setLocalStorageValue = (name: string, value: any) => {
localStorage.setItem(name, JSON.stringify(value))
}
describe('Check X class', () => {
setLocalStorageValue('Xname', data)
const xClass= new XClass()
console.log(xClass.initiate()) ; // it will work
})
2022 December: Nx 14 with Angular 14 Jest.
We have an test-setup.ts file in every app and libs folder. We setting local storage mock globaly.
import 'jest-preset-angular/setup-jest';
Storage.prototype.getItem = jest.fn();
Storage.prototype.setItem = jest.fn();
Storage.prototype.removeItem = jest.fn();
Then localStorage.service.spec.ts file looking like this:
import { LocalStorageService } from './localstorage.service';
describe('LocalStorageService', () => {
let localStorageService: LocalStorageService;
beforeEach(() => {
localStorageService = new LocalStorageService();
});
it('should set "identityKey" in localStorage', async () => {
localStorageService.saveData('identityKey', '99');
expect(window.localStorage.setItem).toHaveBeenCalled();
expect(window.localStorage.setItem).toHaveBeenCalledWith('identityKey', '99');
expect(window.localStorage.setItem).toHaveBeenCalledTimes(1);
});
it('should get "identityKey" from localStorage', async () => {
localStorageService.getData('identityKey');
expect(window.localStorage.getItem).toHaveBeenCalled();
expect(window.localStorage.getItem).toHaveBeenCalledWith('identityKey');
expect(window.localStorage.getItem).toHaveBeenCalledTimes(1);
});
it('should remove "identityKey" from localStorage', async () => {
localStorageService.removeData('identityKey');
expect(window.localStorage.removeItem).toHaveBeenCalled();
expect(window.localStorage.removeItem).toHaveBeenCalledWith('identityKey');
expect(window.localStorage.removeItem).toHaveBeenCalledTimes(1);
});
});
P.S. Sorry for bad indentation, this SatckOverflow window s*cks.
First: I created a file named localStorage.ts(localStorage.js)
class LocalStorageMock {
store: Store;
length: number;
constructor() {
this.store = {};
this.length = 0;
}
key(n: number): any {
if (typeof n === 'undefined') {
throw new Error(
"Uncaught TypeError: Failed to execute 'key' on 'Storage': 1 argument required, but only 0 present."
);
}
if (n >= Object.keys(this.store).length) {
return null;
}
return Object.keys(this.store)[n];
}
getItem(key: string): Store | null {
if (!Object.keys(this.store).includes(key)) {
return null;
}
return this.store[key];
}
setItem(key: string, value: any): undefined {
if (typeof key === 'undefined' && typeof value === 'undefined') {
throw new Error(
"Uncaught TypeError: Failed to execute 'setItem' on 'Storage': 2 arguments required, but only 0 present."
);
}
if (typeof value === 'undefined') {
throw new Error(
"Uncaught TypeError: Failed to execute 'setItem' on 'Storage': 2 arguments required, but only 1 present."
);
}
if (!key) return undefined;
this.store[key] = value.toString() || '';
this.length = Object.keys(this.store).length;
return undefined;
}
removeItem(key: string): undefined {
if (typeof key === 'undefined') {
throw new Error(
"Uncaught TypeError: Failed to execute 'removeItem' on 'Storage': 1 argument required, but only 0 present."
);
}
delete this.store[key];
this.length = Object.keys(this.store).length;
return undefined;
}
clear(): undefined {
this.store = {};
this.length = 0;
return undefined;
}
}
export const getLocalStorageMock = (): any => {
return new LocalStorageMock();
};
global.localStorage = new LocalStorageMock();
Then create a test file named session.test.ts(session.test.js)
import { getLocalStorageMock } from '../localstorage';
describe('session storage', () => {
let localStorage;
beforeEach(() => {
localStorage = getLocalStorageMock();
});
describe('getItem', () => {
it('should return null if the item is undefined', () => {
expect(localStorage.getItem('item')).toBeNull();
});
it("should return '' instead of null", () => {
localStorage.setItem('item', '');
expect(localStorage.getItem('item')).toBe('');
});
it('should return navid', () => {
localStorage.setItem('item', 'navid');
expect(localStorage.getItem('item')).toBe('navid');
});
});
});
This worked for me,
delete global.localStorage;
global.localStorage = {
getItem: () =>
}
I have some AngularJS(pre 1.5) services using nested calls in a project that we are rebuilding in Angular(11).
The services use nested calls but I have no idea how to rebuild them using RXJS.
Any help, or detailed links to understand how I can get the result I need would be great.
I have not been able to find anything sofar that helps me understand how to resolve this.
This is the original service:
function getBalanceGroups() {
return $http.get(url.format("/accounts/{{accountId}}/balance-groups", $stateParams))
.then(function (response) {
_.each(response.data, function (item) {
getBalanceViews(item.accountBalanceGroupId)
.then(function (balanceViewData) {
item.balanceViews = _.sortBy(balanceViewData, function (view) {
return (view.balanceViewId === item.totalIndebtednessViewId) ? 0 : 1;
});
_.each(item.balanceViews, function (view) {
getBalanceSegments(view.accountBalanceViewId)
.then(function (balanceSegmentData) {
view.balanceSegments = balanceSegmentData;
view.totalBalance = 0;
view.totalBalance = _.sumBy(view.balanceSegments, "balance");
});
});
});
});
response.data = _.sortBy(response.data, function (item) {
return (item.isActive && item.isPrimary) ? 0 : 1;
});
return new LinkedList(response.data);
}, function (error) {
$log.error('Unable to return balance group for the balanceChiclet');
});
}
This is what I have so far: (not working - it is returning the final api data response, I need to use the data to use the data to modify the previous response and return the modified data. No idea how )
getBalanceGroups(accountId: number | string): Observable<any> {
let balGroupsUrl = `/accounts/${accountId}/balance-groups`;
return this.http.get(`${this.baseUrl}${balGroupsUrl}`).pipe(
mergeMap( (groups: any) => groups),
flatMap((group:any) => {
group.balanceViews = [];
return this.getBalanceViews( group.accountBalanceGroupId, group )
}),
mergeMap( (views: any) => views),
flatMap((views: any) => {
return this.getBalanceSegments( views.accountBalanceViewId )
}),
catchError((err) => of(err) ),
tap( groups => console.log('groups: 3:', groups) ),
)
}
private getBalanceViews(accountBalanceGroupId: number | string, group): Observable<any> {
let balViewsUrl = `/balance-groups/${accountBalanceGroupId}/balance-views`;
return this.http.get(`${this.baseUrl}${balViewsUrl}`);
}
private getBalanceSegments(accountBalanceViewId: number | string): Observable<any> {
let balSegUrl = `/balance-views/${accountBalanceViewId}/balance-segments`;
return this.http.get(`${this.baseUrl}${balSegUrl}`);
}
Instead of the mergeMap + flatMap (they are synonymous BTW), you could use forkJoin to trigger multiple requests in parallel.
You might have to use multiple nested forkJoin given the nature of the request.
While I've converted the loadash sumBy using Array#reduce, I've left the sort incomplete for you to do it.
Try the following
getBalanceGroups(): Observable<any> {
return this.http.get(`/accounts/${accountId}/balance-groups`, { params: stateParams }).pipe(
switchMap((response: any) =>
forkJoin(
response.data.map((item: any) =>
getBalanceViews(item.accountBalanceGroupId, item).pipe(
map((balanceViewData: any) => ({
...item,
balanceViews: balanceViewData.sort() // <-- incomplete
})),
switchMap((item: any) =>
forkJoin(
item.balanceViews.map((view: any) =>
getBalanceSegments(view.accountBalanceGroupId).pipe(
map((balanceSegmentData: any) => ({
...item,
balanceSegments: balanceSegmentData,
totalBalance: view.balanceSegments.reduce((acc, curr) => acc += curr['balance'], 0)
}))
)
)
)
)
)
)
)
),
map((response: any) => ({
...response,
response.data: response.data.sort() // <-- incomplete
})),
catchError((error: any) => {
console.error('Unable to return balance group for the balanceChiclet');
return of(error);
})
);
}
I've searched the net, and I can't find out a solution. My final goal is to pull all the data from a dynamodb table. The problem is when a table is bigger than 1MB, in the response I'll get one chunk of data and a LastEvaluatedKey parameter (which provides the index I can use in the next call to get the next chunk). The scan operation is documented here if needed.
I'm using reactjs, redux and redux-thunk in my app.
I have used promises moderately in the single or chained formats, but this one is more challenging that I could resolve so far. What puzzles me is the fact that the new calls can not be made without receiving the previous response, so the calls can not be done simultaneously in my opinion. In another hand since the scan operation is a promise (as far as I understand) if I try to return a promise from my own method the action does not receive the results.
I'm very confused and I really like to understand how I can get this to work.
action:
function getDynamodbTableRecords(tableName) {
return dispatch => {
dispatch(request());
var recordsSet = [];
var data = myAwsService.getTableRecords(tableName, null) || {Items:[]};
if (data.Items.length > 0){
data.Items.map(record => {
recordsSet.push(record);
});
dispatch(success(recordsSet));
} else {
dispatch(failure("No Records Found!"));
}
};
function request() { return { type: DATA_LOADING, selectedTable: tableName } }
function success(tableRecords) { return { type: DATA_LOAD_SUCCESS, tableRecords } }
function failure(error) { return { type: DATA_LOAD_FAILED, errors: error } }
}
myAwsService:
function getTableRecords(tableName, lastEvaluatedKey = null) {
getRecordsBatch(tableName, lastEvaluatedKey)
.then(
data => {
if (data.LastEvaluatedKey) {
return getTableRecords(tableName, data.LastEvaluatedKey)
.then(
nextData => {
data.Items = data.Items.concat(nextData.Items);
}
)
}
return data;
}
)
}
function getRecordsBatch(tableName, lastEvaluatedKey = null) {
var awsDynamodb = new DynamoDB();
let params = { TableName: tableName };
if (lastEvaluatedKey) {
params['ExclusiveStartKey'] = lastEvaluatedKey;
}
return new Promise((resolve, reject) => {
awsDynamodb.scan(params, function(err, data) {
if (err) {
reject(err);
}
return resolve(data);
});
});
}
Not sure if your recursive promise is working but I'd do it like this:
function getTableRecords(
tableName,
lastEvaluatedKey = null,
result = { Items: [] }
) {
return getRecordsBatch(tableName, lastEvaluatedKey).then(
data => {
if (data.LastEvaluatedKey) {
return getTableRecords(
tableName,
data.LastEvaluatedKey,
{
...data,
Items: result.Items.concat(data.Items),
}
);
}
return {
...data,
Items: result.Items.concat(data.Items),
};
}
);
}
The action should also dispatch the data.Items and not the promise that getTabelRecords returns and you probably want to dispatch failure action if something goes wrong:
function getDynamodbTableRecords(tableName) {
return async dispatch => {
dispatch(request());
//you probably want the data, not a promise of data
try {
var data = await myAwsService.getTableRecords(
tableName,
null
);
if (data.Items.length > 0) {
//no reason to have the temporary recordSet variable
dispatch(success(data.Items.map(record => record)));
} else {
dispatch(failure('No Records Found!'));
}
} catch (e) {
dispatch(failure(e.message));
}
};
function request() {
return { type: DATA_LOADING, selectedTable: tableName };
}
function success(tableRecords) {
return { type: DATA_LOAD_SUCCESS, tableRecords };
}
function failure(error) {
return { type: DATA_LOAD_FAILED, errors: error };
}
}
I'm trying to test the following function:
// playlist.js
export function getSimplePlaylist() {
// something here
}
export function getPlaylist(type, settings) {
let options = { type };
if (type === 'simple') {
options.getData = () => {
const { videos } = settings;
return getSimplePlaylist(videos);
};
}
// There are few more cases here, but no need to post them
return options;
}
I have tried a bunch of different ways of testing that, but no luck, i.e:
//playlist.spec.js
import * as playlist from '.';
describe('getPlaylist', () => {
beforeEach(() => {
jest.resetAllMocks();
});
it('should get correct option when static ', () => {
playlist.getSimplePlaylist = jest.fn();
const videos = playlist.getPlaylist('simple', { videos: [1, 2, 3] });
videos.getData()
expect(playlist.getSimplePlaylist).toBeCalled();
});
});
Any ideas on how I can test something like the above? Thanks!
If you use the function that way you use the JS functional programming. getPlayList will always call original getSimplePlaylist. If you want to do it you should use class:
class Playlist {
def() {
return 'def';
}
abc(cond) {
if (cond) {
return this.def();
}
}
}
export default Playlist;
and then you could test it:
import Playlist from './playlist';
describe('Name of the group', () => {
it('should ', () => {
const play = new Playlist();
play.def = jest.fn().mockReturnValue('mock');
expect(play.abc(true)).toEqual('mock');
expect(play.def).toBeCalled();
});
});
or you could use function with default implementation and then in test pass additional parameter:
// playlist.js
export function getSimplePlaylist() {
// something here
}
export function getPlaylist(type, settings, simplePlaylistFunc=getSimplePlaylist) {
let options = { type };
if (type === 'simple') {
options.getData = () => {
const { videos } = settings;
return simplePlaylistFunc(videos);
};
}
// There are few more cases here, but no need to post them
return options;
}
Probably the easiest solution here to mock function in a file would be to not export them individually but from an object and use it from that object in the particular module
// playlist.js
function getSimplePlaylist() {
// something here
}
function getPlaylist(type, settings) {
let options = { type };
if (type === 'simple') {
options.getData = () => {
const { videos } = settings;
return funcs.getSimplePlaylist(videos);
};
}
// There are few more cases here, but no need to post them
return options;
}
const funcs = {
getSimplePlaylist,
getPlaylist
}
export default funcs;
Now you can test them like
//playlist.spec.js
import playlist from '.';
describe('getPlaylist', () => {
beforeEach(() => {
jest.resetAllMocks();
});
it('should get correct option when static ', () => {
playlist.getSimplePlaylist = jest.fn();
const videos = playlist.getPlaylist('simple', { videos: [1, 2, 3] });
videos.getData()
expect(playlist.getSimplePlaylist).toBeCalled();
});
});