[javascript] Jasmine.js comparing arrays

Is there a way in jasmine.js to check if two arrays are equal, for example:

arr = [1, 2, 3]
expect(arr).toBe([1, 2, 3])
expect(arr).toEqual([1, 2, 3])

Neither seems to work.

This question is related to javascript jasmine

The answer is


Just did the test and it works with toEqual

please find my test:

http://jsfiddle.net/7q9N7/3/

describe('toEqual', function() {
    it('passes if arrays are equal', function() {
        var arr = [1, 2, 3];
        expect(arr).toEqual([1, 2, 3]);
    });
});

Just for information:

toBe() versus toEqual(): toEqual() checks equivalence. toBe(), on the other hand, makes sure that they're the exact same object.


I had a similar issue where one of the arrays was modified. I was using it for $httpBackend, and the returned object from that was actually a $promise object containing the array (not an Array object).

You can create a jasmine matcher to match the array by creating a toBeArray function:

beforeEach(function() {
  'use strict';
  this.addMatchers({
    toBeArray: function(array) {
      this.message = function() {
        return "Expected " + angular.mock.dump(this.actual) + " to be array " + angular.mock.dump(array) + ".";
      };
      var arraysAreSame = function(x, y) {
         var arraysAreSame = true;
         for(var i; i < x.length; i++)
            if(x[i] !== y[i])
               arraysAreSame = false;
         return arraysAreSame;
      };
      return arraysAreSame(this.actual, array);
    }
  });
});

And then just use it in your tests like the other jasmine matchers:

it('should compare arrays properly', function() {
  var array1, array2;
  /* . . . */
  expect(array1[0]).toBe(array2[0]);
  expect(array1).toBeArray(array2);
});

just for the record you can always compare using JSON.stringify

const arr = [1,2,3]; expect(JSON.stringify(arr)).toBe(JSON.stringify([1,2,3])); expect(JSON.stringify(arr)).toEqual(JSON.stringify([1,2,3]));

It's all meter of taste, this will also work for complex literal objects


You can compare an array like the below mentioned if the array has some values

it('should check if the array are equal', function() {
        var mockArr = [1, 2, 3];
        expect(mockArr ).toEqual([1, 2, 3]);
 });

But if the array that is returned from some function has more than 1 elements and all are zero then verify by using

expect(mockArray[0]).toBe(0);