How to delete an entire array in Ruby and test with RSpec - ruby-on-rails

Question

I'm fairly new to Ruby and am currently taking a full stack course. For one of my projects we are building an addressbook. I have set up how to add an entry to the addressbook, however, I can't seem to figure out how to delete an entry (I make an attempt with the remove_entry method in the AddressBook class below but am not having any luck). We are also supposed to test first with RSpec, have the test fail and then write some code to get it to pass. If I didn't include all the info needed for this question let me know (rookie here). Anyway, here is what I have so far:
RSpec
context ".remove_entry" do
it "removes only one entry from the address book" do
book = AddressBook.new
entry = book.add_entry('Ada Lovelace', '010.012.1815', 'augusta.king#lovelace.com')
book.remove_entry(entry)
expect(entry).to eq nil
end
end
AddressBook class
require_relative "entry.rb"
class AddressBook
attr_accessor :entries
def initialize
#entries = []
end
def add_entry(name, phone, email)
index = 0
#entries.each do |entry|
if name < entry.name
break
end
index += 1
end
#entries.insert(index, Entry.new(name, phone, email))
end
def remove_entry(entry)
#entries.delete(entry)
end
end
Entry class
class Entry
attr_accessor :name, :phone_number, :email
def initialize(name, phone_number, email)
#name = name
#phone_number = phone_number
#email = email
end
def to_s
"Name: #{#name}\nPhone Number: #{#phone_number}\nEmail: #{#email}"
end
end
When testing my code with RSpec I receive the following error message:
.....F
Failures:
1) AddressBook.remove_entry removes only one entry from the address book
Failure/Error: expect(entry).to eq nil
expected: nil
got: [#<Entry:0x00000101bc82f0 #name="Ada Lovelace", #phone_number="010.012.1815", #email="augusta.king#lovelace.com">]
(compared using ==)
# ./spec/address_book_spec.rb:49:in `block (3 levels) in <top (required)>'
Finished in 0.02075 seconds (files took 0.14221 seconds to load)
6 examples, 1 failure
Failed examples:
rspec ./spec/address_book_spec.rb:44 # AddressBook.remove_entry removes only one entry from the address book

Answer 1

Just test that the book.entries association is empty:
expect(book.entries).to be_empty
As book is a local variable in your test, you will not get a false negative result if you keep your test atomic. Some best practices on rspec.
Edit:
You can also check the entry was not in the set:
expect(book.entries.index(entry)).to be_nil
or test the change of the array length with:
expect { book.remove_entry(entry) }.to change{book.entries.count}.by(-1)
If you wonder for the be_xxx syntax sugar, if the object respond to xxx?, then you can use be_xxx in your tests (predicate matchers)

Answer 2

I think your expect has an issue. The entry variable is not set to nil, but the entry inside book would be nil.
I think something like this would work better:
expect(book.entries.find { |e| e.name == "Ada Lovelace" }).to eq nil
Better still, your AddressBook could have its own find method, which would make the expect param much nicer, like book.find(:name => "Ada Lovelace").
Finally, I would also put an expect call before the remove_entry call, to make sure its result equals entry.