CODEWITHSUNDEEP
javascriptmocha.jschai
blub
blub

Reputation: 9177

Chai expect: an array to contain an object with at least these properties and values

I'm trying to validate that an array of objects like this:

[
    {
        a: 1,
        b: 2,
        c: 3
    },
    {
        a: 4,
        b: 5,
        c: 6
    },
    ...
]

contains at least one object with both { a: 1 } and { c: 3 }:

I thought I could do this with chai-things, but I don't know all the properties of the object to be able to use

expect(array).to.include.something.that.deep.equals({ ??, a: 1, c: 3});

and contain.a.thing.with.property doesn't work with multiple properties :/

What's the best way to test something like this?

Upvotes: 23

Views: 30418

Answers (7)

k06a
k06a

Reputation: 18745

Found the simplest solution without external dependencies:

expect(
    [
        { a: 1, b: 2, c: 3 },
        { a: 4, b: 5, c: 6 },
    ].map(({a,b}) => { return {a,b} })
).to.include.deep.members([
    { a: 1, b: 2 },
]);

Upvotes: 2

Asier Villanueva
Asier Villanueva

Reputation: 158

Solution without third libraries or plugins:

let array = [
    { a: 1, b: 2, c: 3 },
    { a: 4, b: 5, c: 6 }
];

let match = array.map(({a, c}) => ({a, c})).to.deep.include({ a:1, c:3});

Upvotes: 4

blub
blub

Reputation: 9177

Most elegant solution I could come up with (with the help of lodash):

expect(_.some(array, { 'a': 1, 'c': 3 })).to.be.true;

Upvotes: 20

Ken Tsoi
Ken Tsoi

Reputation: 1303

Most straight forward way I can think of is:

const chai = require('chai');
const expect = chai.expect;

chai.use(require('chai-like'));
chai.use(require('chai-things'));

expect([
  {
    a: 1,
    b: 2,
    c: 3,
  },
  {
    a: 4,
    b: 5,
    c: 6,
  },
]).to.be.an('array').that.contains.something.like({ a: 1, c: 3 });

Upvotes: 4

Choonkies
Choonkies

Reputation: 143

Seems like the chai-subset plugin from chai seems to have done the trick. Here is something I have working:

const chai = require('chai');
const chaiSubset = require('chai-subset');
chai.use(chaiSubset);
const expect = chai.expect;

 expect([ { type: 'text',
    id: 'name',
    name: 'name',
    placeholder: 'John Smith',
    required: 'required' },
  { type: 'email',
    id: 'email',
    name: 'email',
    placeholder: '[email protected]',
    required: 'required' },
  { type: 'submit' } ]).containSubset([{ type: 'text', type: 'email', type: 'submit' }]);

Upvotes: 3

Druckles
Druckles

Reputation: 3782

The desired solution seems to be something like:

expect(array).to.include.something.that.includes({a: 1, c: 3});

I.e. array contains an item which includes those properties. Unfortunately, it appears to not be supported by chai-things at the moment. For the foreseeable future.

After a number of different attempts, I've found that converting the original array makes the task easier. This should work without additional libraries:

// Get items that interest us/remove items that don't.
const simplifiedArray = array.map(x => ({a: x.a, c: x.c}));
// Now we can do a simple comparison.
expect(simplifiedArray).to.deep.include({a: 1, c: 3});

This also allows you to check for several objects at the same time (my use case).

expect(simplifiedArray).to.include.deep.members([{
  a: 1,
  c: 3
}, {
  a: 3,
  c: 5
}]);

Upvotes: 18

Andy
Andy

Reputation: 63524

You could write your own function to test the array. In this example you pass in the array and the object containing the relevant key/value pairs:

function deepContains(arr, search) {

  // first grab the keys from the search object
  // we'll use the length later to check to see if we can
  // break out of the loop
  var searchKeys = Object.keys(search);

  // loop over the array, setting our check variable to 0
  for (var check = 0, i = 0; i < arr.length; i++) {
    var el = arr[i], keys = Object.keys(el);

    // loop over each array object's keys
    for (var ii = 0; ii < keys.length; ii++) {
      var key = keys[ii];

      // if there is a corresponding key/value pair in the
      // search object increment the check variable
      if (search[key] && search[key] === el[key]) check++;
    }

    // if we have found an object that contains a match
    // for the search object return from the function, otherwise
    // iterate again
    if (check === searchKeys.length) return true;
  }
  return false;
}

deepContains(data, { a: 4, c: 6 }); // true
deepContains(data, { a: 1, c: 6 }); // false

DEMO

Upvotes: 0

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