Rspec expect to receive not working for object in array-CodePudding

I'm sure this is answered somewhere; I can't seem to phrase my google search right though. I'm trying to test that a method is called on an object, but the method isn't called on the specific object in the spec. The method is called on the last item in a collection, which I've confirmed is the same underlying object as the one in the spec. I'm not sure how clear that was, so here is an example:

expect(@email).to receive(:send) # fails
puts @user.emails.last == @email # true
@user.emails.last.send

As a sanity check, this spec passes. However the code I'm testing has @user.emails.last.send in it, so I'm trying to figure out how to make the spec above pass.

expect(@email).to receive(:send) # passes
@email.send

Edit:

@user.emails.last.equal?(@email) returns false, so as suspected by @spickermann and @Grzegorz the @user.emails.last and @email are two instances of the same object. So I guess what I'm asking is how can I test that the send method was called on a specific object (ignoring what particular instance of that object it was called on). My question is actually the same as this one that I just found Rspec: Test if instance method was called on specific record with ActiveRecord.

CodePudding user response：

It's possible that == method is defined on the mail object in a way that it returns true if some attributes are the same, but it doesn't care if the object is the same.

@user.emails.last == @email

This is the case with a simple string:

>> "d" == "d"
=> true
>> "d".object_id == "d".object_id
=> false

So It is possible that @mail and @user.emails.last are different objects in memory, but return true when using == method.

You can confirm that there's nothing wrong with your expectation like this:

expect(@user.emails.last).to receive(:send) # should pass now
@user.emails.last.send

You didn't share much code for context, so it's not clear what a "good" solution in your case could be. But I hope this will point you in the right direction.

CodePudding user response：

In my case I'm able to work around this by returning the Email instance (@user.emails.last) from the send_email method and ensuring that is the same object as the @email object in the spec. E.g.,:

# The `send_email` method calls `@user.emails.last.send` and returns `@user.emails.last`
email = @user.send_email
expect(email).to eq(@email) # passes!