I have the following setup:
// uuid-wrapper.ts
import { v4 as uuidV4 } from 'uuid';
const uuid: () => string = uuidV4;
export { uuid };
// uuid-wrapper.spec.ts
import { uuid } from './uuid-wrapper';
describe('uuid-wrapper', () => {
console.log(uuid());
});
This works fine runtime, but it breaks in test. I'm trying to migrate to Jest 29 and I'm getting the following error:
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,jest){export { default as v1 } from './v1.js';
^^^^^^
SyntaxError: Unexpected token 'export'
From uuid's repo I found a workaround which, after applied and my jest.config.js looks like this:
module.exports = {
moduleNameMapper: {
uuid: require.resolve("uuid"),
},
};
This gives me a different error but I still have no idea what it means:
> jest uuid-wrapper --no-coverage
FAIL src/uuid-wrapper/uuid-wrapper.spec.ts
● Test suite failed to run
TypeError: (0 , uuid_wrapper_1.uuid) is not a function
In fact, any function I export from this file (uuid-wrapper.ts) is not resolved. I have other tests that follow a similar pattern of reexporting packages but only this one breaks. I'm using uuid 9.0.0 and jest 29.1.2.
Edit: After a bit more testing, it turns out that anything I import into the test is "not a function".
uuid ships as an ESModule and Jest should not need to transform it. Add it to your transformIgnorePatterns in your Jest config:
module.exports = {
transformIgnorePatterns: ['node_modules/(?!(uuid))'],
}
Edit: After a bit more testing, it turns out that anything I import into the test is "not a function".
I had very similar symptoms once: builds and works as excepted, yet ...is not function in jest. The culprit was a circular dependency I accidentally introduced with my story. Maybe check for that.
As I suspected, the issue was in the naming. Renaming the files and directory to just wrapper solved the issue.
Related
Setup
I want to unit test my electron app with jest. For this I have the following setup:
I use jest and use #kayahr/jest-electron-runner to run it with electron instead of node. Additionally, since it is a typescript project, I use ts-jest.
My jest.config.js looks like this:
module.exports = {
collectCoverage: true,
coverageDirectory: 'coverage',
coverageProvider: 'v8',
preset: 'ts-jest',
runner: '#kayahr/jest-electron-runner/main',
testEnvironment: 'node',
};
The test is expected to run in the main process. I have reduced my code to the following example function:
import { app } from 'electron';
export function bar() {
console.log('in bar', app); //this is undefined when mocked, but I have a real module if not mocked
const baz = app.getAppPath();
return baz;
}
The test file:
import electron1 from 'electron';
import { bar } from '../src/main/foo';
console.log('in test', electron1); //this is undefined in the test file after import
// jest.mock('electron1'); -> this does just nothing, still undefined
const electron = require('electron');
console.log('in test after require', electron); //I have something here yay
jest.mock('electron'); //-> but if I comment this in -> it is {} but no mock at all
it('should mock app', () => {
bar();
expect(electron.app).toBeCalled();
});
What do I want to do?
I want to mock electron.app with jest to look whether it was called or not.
What is the problem?
Mocking electron does not work. In contrast to other modules like fs-extra where jest.mock() behaves as expected.
I don't understand the behavior happening here:
Importing "electron" via import in the file containing the tests (not the file to be tested!) does not work (other modules work well), but require("electron") does.
I do have the electron module if not mocked in bar(), but after mocking not
while jest.mock("fs-extra") works, after jest.mock("electron") electron is only an empty object, not a mock
I would really like to understand what I did wrong or what the problem is. Switching back to #jest-runner/electron does not seem to be an option, since it is not maintained anymore. Also I don't know if this is even the root of the problem.
Has anyone seen this behavior before and can give me a hint where to start searching?
I am trying to use koa-tree-router and koa-bodyparser at the same time, but I keep getting TypeScript errors:
export const userLoggingRouter = new KoaTreeRouter<any, DefaultContext>();
userLoggingRouter.post('/logs/action', (ctx) => {
const logEntries = ctx.request.body;
const user = ctx.state.user;
// ...
});
error TS2339: Property 'body' does not exist on type 'Request'.
I have #types/koa-bodyparser installed, and it contains the following definition:
import * as Koa from 'koa';
declare module 'koa' {
interface Request {
body: string | Record<string, unknown>;
rawBody: string;
}
}
But it doesn't seem to do anything. I found this question, but importing koa-bodyparser directly also does not do anything. How do I get TypeScript to recognize the extended Request type?
Edit: Creating a .d.ts file inside my project containing the following:
import {Request} from "koa";
declare module "koa" {
interface Request {
body: any;
}
}
Made the compile error go away, but this seems like an inelegant solution because I would have to copy over type information for every package that modifies koa.Request.
This was happening because I was using Yarn PnP and I had two different versions of #types/koa installed. Once I added a resolutions field to my package.json that forced all of the other TypeScript definitions to use the same version of #types/koa, everything worked.
I am currently having a TypeScript project that includes Ethers.js, which in turn includes bn.js.
The problem is
SyntaxError: The requested module './../../../bn.js/lib/bn.js' does not provide an export named 'default'
It appears to me this is because BN is in UMD format (see at https://github.com/indutny/bn.js/blob/master/lib/bn.js#L1)
(function (module, exports) {
'use strict';
// Utils
function assert (val, msg) {
if (!val) throw new Error(msg || 'Assertion failed');
}
and the correponding .ts declaration is
"use strict";
/**
* BigNumber
*
* A wrapper around the BN.js object. We use the BN.js library
* because it is used by elliptic, so it is required regardless.
*
*/
import _BN from "bn.js";
import BN = _BN.BN;
import { Bytes, Hexable, hexlify, isBytes, isHexString } from "#ethersproject/bytes";
import { Logger } from "#ethersproject/logger";
import { version } from "./_version";
const logger = new Logger(version);
It may be there's something that could be done at importing (source) or in Rollup. Difficult to tell!
Here is a screenshot of the build errors (one variation, depending on if building or running directly)
Question: Is there a way to transform this format to an ESM format in application Rollup pipeline?
I have tried using #rollup/plugin-commonjs and #rollup/plugin-node-resolve as in
resolve({ browser: true, preferBuiltins: false }), commonjs()]
(or see the project as whole at https://github.com/veikkoeeva/erc1155sample/blob/main/web/rollup.config.js, the error shows with npm run test or npm run start (in console log)).
Thus far I've had no luck cracking this, though. Hence coming here wondering if there's a dumb issue I don't see or if this is a genuinely tougher issue.
Edit: indeed, following https://rollupjs.org/guide/en/#error-name-is-not-exported-by-module and maybe named exports is the key here...
I'm trying to use cy.taks() to load certain datasets to mongo before a test is run. But I'm getting errors. I've got a module where I export 2 functions, one from dropping a collection, and the other to load an object to a collection. Here is my cypress/plugins/index.js:
module.exports = (on, config) => {
on("task", {
"defaults:db": () => {
const {dropCollection, createUser } = require("../../lib/connectDB");
dropCollection("users");
createUser(userData)
},
});
};
Here is my /lib/connecDB.js:
export function dropCollection(collection) {
return mongoose.connection.dropCollection(collection);
}
export async function createUserInDB(userData) {
await User.create(userData);
}
So when I run the test, I'm getting:
cy.task('defaults:db') failed with the following error:
Unexpected token 'export'
Tried as well importing these function outside the index.js export, but getting same result.
I'd say it is something about export/import. The functions are exported as ES6, and imported as ES5.
I've tried to import the function the ES6 like:
import { dropCollection, createUser } from '../lib/connectDB'
And then export the plugin function also as ES6, but then I get:
Error: The plugins file is missing or invalid.
Your `pluginsFile` is set to `C:\Users\someRoute\cypress\plugins\index.js`, but either the file is missing, it contains a syntax error, or threw an error when required. The `pluginsFile` must be a `.js`, `.ts`, or `.coffee` file.
I've also tried to import required modules outside the function like:
const globalDbUtils = require('../lib/connectDB')
And then use the functions as
globalDbUtils.dropCollection("collectionName")
globalDbUtils.createUser(userData)
But I'm getting last error. I've tried pretty much everything, I tried to import Mongoose models straight, mongo client etc...Also I tried to import just one function and return it (just copy/pasting official doc...) but cannot make it work. I researched for a couple of days getting nothing, I found there is a npm package that helps u doing this, but since cypress allows you to do this by using no more plugins, I'd like to do it with no more tools than cypress itself.
Anyone knows what I am doing wrong?
Thanks in advance!
You need to use require instead of import at the top of your file and when exporting at the bottom use
module.exports = { createUserInDB }
Instead of exporting as you are currently doing.
I'm using AVA + sinon to build my unit test. Since I need ES6 modules and I don't like babel, I'm using mjs files all over my project, including the test files. I use "--experimental-modules" argument to start my project and I use "esm" package in the test. The following is my ava config and the test code.
"ava": {
"require": [
"esm"
],
"babel": false,
"extensions": [
"mjs"
]
},
// test.mjs
import test from 'ava';
import sinon from 'sinon';
import { receiver } from '../src/receiver';
import * as factory from '../src/factory';
test('pipeline get called', async t => {
const stub_factory = sinon.stub(factory, 'backbone_factory');
t.pass();
});
But I get the error message:
TypeError {
message: 'ES Modules cannot be stubbed',
}
How can I stub an ES6 module without babel?
According to John-David Dalton, the creator of the esm package, it is only possible to mutate the namespaces of *.js files - *.mjs files are locked down.
That means Sinon (and all other software) is not able to stub these modules - exactly as the error message points out. There are two ways to fix the issue here:
Just rename the files' extension to .js to make the exports mutable. This is the least invasive, as the mutableNamespace option is on by default for esm. This only applies when you use the esm loader, of course.
Use a dedicated module loader that proxies all the imports and replaces them with one of your liking.
The tech stack agnostic terminology for option 2 is a link seam - essentially replacing Node's default module loader. Usually one could use Quibble, ESMock, proxyquire or rewire, meaning the test above would look something like this when using Proxyquire:
// assuming that `receiver` uses `factory` internally
// comment out the import - we'll use proxyquire
// import * as factory from '../src/factory';
// import { receiver } from '../src/receiver';
const factory = { backbone_factory: sinon.stub() };
const receiver = proxyquire('../src/receiver', { './factory' : factory });
Modifying the proxyquire example to use Quibble or ESMock (both supports ESM natively) should be trivial.
Sinon needs to evolve with the times or be left behind (ESM is becoming defacto now with Node 12) as it is turning out to be a giant pain to use due to its many limitations.
This article provides a workaround (actually 4, but I only found 1 to be acceptable). In my case, I was exporting functions from a module directly and getting this error: ES Modules cannot be stubbed
export function abc() {
}
The solution was to put the functions into a class and export that instead:
export class Utils {
abc() {
}
}
notice that the function keyword is removed in the method syntax.
Happy Coding - hope Sinon makes it in the long run, but it's not looking good given its excessive rigidity.
Sticking with the questions Headline „Stub an export from a native ES Module without babel“ here's my take, using mocha and esmock:
(credits: certainly #oligofren brought me on the right path…)
package.json:
"scripts": {
...
"test": "mocha --loader=esmock",
"devDependencies": {
"esmock": "^2.1.0",
"mocha": "^10.2.0",
TestDad.js (a class)
import { sonBar } from './testSon.js'
export default class TestDad {
constructor() {
console.log(purple('constructing TestDad, calling...'))
sonBar()
}
}
testSon.js (a 'util' library)
export const sonFoo = () => {
console.log(`Original Son 'foo' and here, my brother... `)
sonBar()
}
export const sonBar = () => {
console.log(`Original Son bar`)
}
export default { sonFoo, sonBar }
esmockTest.js
import esmock from 'esmock'
describe.only(autoSuiteName(import.meta.url),
() => {
it('Test 1', async() => {
const TestDad = await esmock('../src/commands/TestDad.js', {
'../src/commands/testSon.js': {
sonBar: () => { console.log('STEPSON Bar') }
}
})
// eslint-disable-next-line no-new
new TestDad()
})
it('Test 2', async() => {
const testSon = await esmock('../src/commands/testSon.js')
testSon.sonBar = () => { console.log('ANOTHER STEPSON Bar') }
testSon.sonFoo() // still original
testSon.sonBar() // different now
})
})
autoSuiteName(import.meta.url)
regarding Test1
working nicely, import bended as desired.
regarding Test1
Bending a single function to do something else is not a problem.
(but then there is not much test value in calling your very own function you just defined, is there?)
Enclosed function calls within the module (i.e. from sonFoo to sonBar) remain what they are, they are indeed a closure, still pointing to the prior function
Btw also tested that: No better results with sinon.callsFake() (would have been surprising if there was…)