I found a similar problem here, but there doesn't seem to be an answer.
I'm trying to test an ES6 class using Jest, like so:
// src/myclass.js
export default class MyClass {
constructor(options) {
// currently this is empty while I debug this problem
}
}
and the test:
// test/myclass.test.js
import { MyClass } from '../src/myclass.js';
describe("Test Constructor", () => {
test("doesn't throw error when constructed", async () => {
expect(() => {
const testMyClass = new MyClass();
}).not.toThrowError();
}
});
When I run the test, Jest throws an error saying:
TypeError: _myClass.MyClass is not a constructor
My best guess is that this is an issue with the babel config, but I can't seem to figure it out. If I change MyClass
to a function instead of a class and drop the export/import (i.e., the pre-class way of doing things) then it works as expected.
Here's my config in package.json:
"devDependencies": {
"@babel/core": "^7.1.2",
"@babel/preset-env": "^7.1.0",
"babel-core": "^7.0.0-bridge.0",
"gulp": "^3.9.1",
"gulp-babel": "^8.0.0",
"gulp-jest": "^4.0.2",
"gulp-rename": "^1.4.0",
"gulp-uglify": "^3.0.1",
"jest": "^23.6.0",
"jest-cli": "^23.6.0",
"pump": "^3.0.0",
"regenerator-runtime": "^0.12.1"
},
"babel": {
"presets": [
"@babel/preset-env"
]
},
"jest": {
"testPathIgnorePatterns": [
"<rootDir>/node_modules/",
"<rootDir>/test/._*.test.js"
],
"testEnvironment": "jsdom",
"setupFiles": [
"<rootDir>/src/myclass.es6.js"
]
}
Your import and export syntaxes do not match. You'll need to change one or the other for this to work. If you want to use the default export, eg:
export default class MyClass { ... }
Then the corresponding import is:
import MyClass from '../src/myclass.js'
Or if you'd like to continue using the same import syntax, then remove the 'default' when exporting:
export class MyClass { ... }
Then:
import { MyClass } from '../src/myclass.js'