The first one is generally preferred. It’s a declaration, not an expression value, which has subtle advantages. And it can easily be named if you want, which is a good practice. Also, arrow functions have a few disadvantages in certain situations, so unless you absolutely need them to preserve a this value (etc.) you’d rather … Read more
It looks like you didn’t import jest, so you have to just add this line to the top of the file: import {jest} from ‘@jest/globals’ For more details, see this issue on native support for ES6 modules in Jest.
No, modules don’t care about extensions. It just needs to be a name that resolves to a source file. In your case, http://localhost/bla/src/drawImage is not a file while http://localhost/bla/src/drawImage.js is, so that’s where there error comes from. You can either add the .js in all your import statements, or configure your server to ignore the … Read more
It’s supported in: Safari 10.1 Chrome 61 Firefox 54 – behind the dom.moduleScripts.enabled setting in about:config. Edge 16
You can resolve this by: Just add js as an extension to file Before: import std from ‘./route/student’ After: import std from ‘./route/student.js’
If you want to mock a private function, try to use the prototype. For example, you need to mock privateFunction of the following class: export class Module { public publicFunction() { // do something this.privateFunction(); // do something } private privateFunction() { // do something } } So you should use Module.prototype in the jest.spyOn … Read more
I eventually found out what the problem was. It turns out it was there in ts-jest’s README all the time. There’s a section in the README titled Using ES2015+ features in Javascript files. In these cases, you need to instruct jest to use babel-jest as a transform for .js files. “jest”: { “transform”: { “^.+\\.jsx?$”: … Read more
This might be caused by a cyclic dependencies (i.e. moduleA imports module B and vice versa at the same time). Take a deeper look at your code.
There is one solution for all of this that doesn’t involve query string. let’s say your module files are in /modules/. Use relative module resolution ./ or ../ when importing modules and then rewrite your paths in server side to include version number. Use something like /modules/x.x.x/ then rewrite path to /modules/. Now you can … Read more
You can use either es6 import or require js to import your js files in your jest tests. When using es6 import you should know that jest is trying to resolve all the dependencies and also calls the constructor for the class that you are importing. During this step, you cannot mock it. The dependency … Read more