CODEWITHSUNDEEP
javascriptnode.jschai
FuManchu
FuManchu

Reputation: 145

Chai/Node.js: Expect(value).to.be.NaN issue

I have these form fields I need to validate with chai expect. They all work (I get errors) except for the fields that require characters - expect(value).to.be.NaN is not working... The code:

var inputs = [response.fname, response.surname,
  response.age, response.password
];

for (var i = 0; i < inputs.length; i++) {
  var stackErrors = validate(i);
  console.log(stackErrors);
}

function validate(i) {
  var fields = inputs[i];

  try {
    if (i == 0) {
      expect(fields).to.be.Nan;
    }

    if (i == 1) {
      expect(fields).to.be.Nan;
    }

    if (i == 2) {
      expect(fields).not.to.be.NaN;
    }

    if (i == 3) {
      expect(fields).to.have.length.above(6);
    }

    return "OK";
  } catch (error) {
    console.log(error);
    return error;
  }
}

But if test the field like in the example bellow, right after the inputs array, I get the expected assertion error...:

expect(inputs[0]).to.be.NaN;

Why is this happening? Thanks in advance

Upvotes: 0

Views: 3059

Answers (3)

EladTal
EladTal

Reputation: 2856

From playwright official documentation toBeNaN Added in: v1.9

Ensures that value is NaN:

const value = NaN;
expect(value).toBeNaN();

Upvotes: 0

FuManchu
FuManchu

Reputation: 145

Thanks to the hint of @Lazyexpert (I've noticed you have Nan in your code, it is not the same as NaN.), I found the obvious solution...(a case sensitive issue, actualy)

try {
    if (i == 0) {
      expect(fields).to.be.NaN; //instead of Nan...
    }

Upvotes: 3

Lazyexpert
Lazyexpert

Reputation: 3154

Assuming this code:

Number.isNaN(NaN) // true

And:

Number.isNaN(5) // false

I would do a small workaround(just to make it fast), something like this:

expect(Number.isNaN(inputs[0])).to.be.eq(false);

UPDATE: I've noticed you have Nan in your code, it is not the same as NaN.

I'm not sure how it is implemented, but as far as it is chained, try this:

expect(undefined).to.be.eq.Nan

I think you should receive true in this case.

Upvotes: 2

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