Jasmine has built-in matchers toBe
and toEqual
. If I have an object like this:
function Money(amount, currency){
this.amount = amount;
this.currency = currency;
this.sum = function (money){
return new Money(200, "USD");
}
}
and try to compare new Money(200, "USD")
and the result of sum, these built-in matchers will not work as expected. I have managed to implement a work-around based on a custom equals
method and custom matcher, but it just seems to much work.
What is the standard way to compare objects in Jasmine?
I was looking for the same thing and found an existing way to do so without any custom code or matchers. Use toEqual()
.
If you're looking to compare partial objects, you might consider:
describe("jasmine.objectContaining", function() {
var foo;
beforeEach(function() {
foo = {
a: 1,
b: 2,
bar: "baz"
};
});
it("matches objects with the expect key/value pairs", function() {
expect(foo).toEqual(jasmine.objectContaining({
bar: "baz"
}));
});
});
cf. jasmine.github.io/partial-matching
Its the expected behavior, as two instances of an object are not the same in JavaScript.
function Money(amount, currency){
this.amount = amount;
this.currency = currency;
this.sum = function (money){
return new Money(200, "USD");
}
}
var a = new Money(200, "USD")
var b = a.sum();
console.log(a == b) //false
console.log(a === b) //false
For a clean test you should write your own matcher that compares amount
and currency
:
beforeEach(function() {
this.addMatchers({
sameAmountOfMoney: function(expected) {
return this.actual.currency == expected.currency && this.actual.amount == expected.amount;
}
});
});
Your problem is with truthyness. You are trying to compare two different instances of an object which is true for regular equality ( a == b ) but not true for strict equality ( a === b). The comparator that jasmine uses is
jasmine.Env.equals_() which looks for strict equality.
To accomplish what you need without changing your code you can use the regular equality by checking for truthyness with something a little like the following:
expect(money1.sum() == money2.sum()).toBeTruthy();