Using Rspec, how can I test a method which calls a method from another class in ruby - ruby

Question

My Transaction class has a method 'balance' which calls a method 'balance_after' from my Account class. I would like to make a test where I can check the 'balance_after' method is being called with the 'balance' method. I am new to both ruby and testing, so I appreciate any guidance! I am using simple-cov to get my coverage and i'd like to hit 100% if possible. I hope I have provided enough information. Thanks in advance!
Failures:
1) Transaction#balance checks balance
Failure/Error: #account.balance_after(self)
NoMethodError:
undefined method `balance_after' for :account:Symbol
# ./lib/transaction.rb:11:in `balance'
# ./spec/transaction_spec.rb:19:in `block (3 levels) in <top (required)>'
Finished in 0.04089 seconds (files took 0.87223 seconds to load)
10 examples, 1 failure
Failed examples:
rspec ./spec/transaction_spec.rb:18 # Transaction#balance checks balance
COVERAGE: 98.55% -- 68/69 lines in 4 files
+----------+--------------------+-------+--------+---------+
| coverage | file | lines | missed | missing |
+----------+--------------------+-------+--------+---------+
| 90.91% | lib/transaction.rb | 11 | 1 | 16 |
+----------+--------------------+-------+--------+---------+
My Transaction class
class Transaction
attr_reader :amount, :account, :timestamp
def initialize(amount, account)
#amount = amount
#account = account
#timestamp = Time.now.strftime("%d/%m/%Y")
end
def balance
#account.balance_after(self)
end
def formate
#amount > 0 ? (puts "#{#timestamp}|| #{#amount} || || #{balance}")
: (puts "#{#timestamp}|| || #{#amount.abs} || #{balance}")
end
end
My Account class
require_relative 'transaction'
class Account
attr_reader :balance, :transactions
HEADER = 'date || credit || debit || balance'
def initialize
#balance = 0
#transactions = []
end
def deposit(amount)
#balance += amount
#transactions << Transaction.new(amount, self)
end
def withdraw(amount)
#balance -= amount
#transactions << Transaction.new(-amount, self)
end
def balance_after(transaction)
index = #transactions.find_index(transaction)
#transactions[0..index].map(&:amount).sum
end
def print_statement
puts HEADER
#transactions.reverse.map(&:formate)
end
end
My Transaction spec
require 'transaction'
describe Transaction do
let(:transaction) { Transaction.new(:amount, :account) }
let(:timestamp) { Time.now.strftime('%d/%m/%Y') }
describe '#initilalize' do
it 'validates class' do
expect(transaction).to be_a Transaction
end
it 'stores dates' do
expect(transaction.timestamp).to eq timestamp
end
end
describe '#balance' do
it 'checks balance' do
expect(transaction.balance).to eq true
end
end
end

Answer 1

You have to call the method correctly. Transaction.new takes an amount, presumably a number, and some sort of Account object which has balance_after defined. You've given it two Symbols.
describe Transaction do
let(:account) { Account.new }
let(:amount) { 1.23 }
let(:transaction) { Transaction.new(amount, account) }
let(:timestamp) { Time.now.strftime('%d/%m/%Y') }
Then check that it returns what you expect. balance does not return true or false, it returns a balance. Specifically, it's just a pass through to account.balance_after(transaction), so test that.
describe '#balance' do
it 'checks balance' do
expect(transaction.balance).to eq account.balance_after(transaction)
end
end
This might seem circular, but this is just an integration test. account.balance_after would be unit tested as part of Account's tests. There's no need to repeat those tests here.