CODEWITHSUNDEEP
javascriptunit-testingecmascript-6mocha.js
30secondstosam
30secondstosam

Reputation: 4686

Mocha ES6 Babel "TypeError: undefined is not a function"

I'm currently trying to implement simple tests for my JavaScript components and I am getting the error: TypeError: undefined is not a function from my test.

This is erroring on this line within my class:

this.options = Object.assign({}, this.defaults, options);

this.defaults is an object of default options and options is currently an object with nothing in.

I am running the code from CLI using npm test which resolves to this: mocha ./src/components/myComponent/myComponent.spec.js --compilers js:babel-register

Does anyone know why this error occurs?

Upvotes: 1

Views: 795

Answers (2)

Ismail RBOUH
Ismail RBOUH

Reputation: 10460

Babel needs a plugin in order to transform Object.assign, please try to install babel-plugin-transform-object-assign.

Upvotes: 1

Warren Mira
Warren Mira

Reputation: 242

What version of node are you running with? Object.assign won't be available throughout. You might want to use object-assign package

const assign = require('object-assign');
...
this.options = assign({}, this.defauts, options)

Upvotes: 0

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