I was looking for this too, and apart from this question, I also found this discussion regarding a feature request that led to the addition of closeTo. With that you can specify a value and a +/- delta, so basically it lets you specify the precision with which to check the result. percentage.should.be.closeTo(6.666, 0.001); or … Read more
The easiest way to run Mocha tests written in ES6 is compiling them on-the-fly using Mocha –require @babel/register option (see https://github.com/mochajs/mocha/wiki/compilers-deprecation#what-should-i-use-instead-then). Of course, you need to make sure to install the corresponding modules and set up the .babelrc accordingly package.json: “dependencies”: { “@babel/cli”: “^7.7.4”, “@babel/core”: “^7.7.4”, “@babel/preset-env”: “^7.7.4”, “@babel/register”: “^7.7.4”, … } .babelrc: { “presets”: … Read more
It is very difficult to test a situation where an action has not occured. With this type of assertion, you can really only say: “The XHR request was not made within the 400ms that Cypress looked for this XHR request to have been made (or whatever you set your timeout to be)” This doesn’t really … Read more
Strictly equal (or ===) means that your are comparing exactly the same object to itself: var myObj = { testProperty: ‘testValue’ }; var anotherReference = myObj; expect(myObj).to.equal(anotherReference); // The same object, only referenced by another variable expect(myObj).to.not.equal({testProperty: ‘testValue’}); // Even though it has the same property and value, it is not exactly the same object … Read more
Asserts that the target is a member of the given array list. However, it’s often best to assert that the target is equal to its expected value. expect(1).to.be.oneOf([1, 2, 3]); expect(1).to.not.be.oneOf([2, 3, 4]); https://www.chaijs.com/api/bdd/#method_oneof
This question was asked a while back but may still be interesting, especially for people who are new to sinon. this.spied.reset() is not needed as Obj.prototype.spiedMethod.restore(); removes the spy. Update 2018-03-22: As pointed out in some of the comments below my answer, stub.reset will do two things: Remove the stub behaviour Remove the stub history … Read more
Just to make it clear to other readers: You can add /*jshint expr: true*/ to the top of the test files, so it only allows it in the test files. In the rare case that you use that kind of expressions in your code, you can add the expr: true option to the jshint config … Read more
If you’re using Chai-As-Promised (as you say you are), then it allows for chaining off of rejectedWith – and it sets the chain assertion object to be the error object – meaning anything after rejectedWith() is now going to assert on the Error. This lets you do cool things like: return expect(foo()).to.eventually .be.rejectedWith(“my error message”) … Read more
The problem with this approach is that (await fails()).should.throw(Error) doesn’t make sense. await resolves a Promise. If the Promise rejects, it throws the rejected value. So (await fails()).should.throw(Error) can never work: if fails() rejects, an error is thrown, and .should.throw(Error) is never executed. The most idiomatic option you have is to use Chai’s rejectedWith property, … Read more
You can serialize simple data to check for equality: data1 = {firstName: ‘John’, lastName: ‘Smith’}; data2 = {firstName: ‘Jane’, lastName: ‘Smith’}; JSON.stringify(data1) === JSON.stringify(data2) This will give you something like ‘{firstName:”John”,lastName:”Smith”}’ === ‘{firstName:”Jane”,lastName:”Smith”}’ As a function… function compare(a, b) { return JSON.stringify(a) === JSON.stringify(b); } compare(data1, data2); EDIT If you’re using chai like you say, … Read more