3. Object Oriented Basics

Define a class BookInStock which represents a book with an ISBN number, isbn, and price of the book as a floating-point number, price, as attributes. Run associated tests via: $ rspec -e 'getters and setters' spec/part3_spec.rb (Make sure you are in the correct directory: cd assignment)

The constructor should accept the ISBN number (a string, since in real life ISBN numbers can begin with zero and can include hyphens) as the first argument and the price as the second argument, and should raise ArgumentError (one of Ruby’s built-in exception types) if the ISBN number is the empty string or if the price is less than or equal to zero. Include the proper getters and setters for these attributes. Run associated tests via: $ rspec -e 'constructor' spec/part3_spec.rb

Include a method price_as_string that returns the price of the book formatted with a leading dollar sign and two decimal places, that is, a price of 20 should format as $20.00 and a price of 33.8 should format as $33.80. Check out formatted string methods in Ruby. Run associated tests via: $ rspec -e '#price_as_string' spec/part3_spec.rb

You can check your progress on all of the above by running rspec spec/part3_spec.rb.

rspec spec/part3_spec.rb

Submission (10 points)

You should now be ready to submit your assignment. Remember to run your test cases once more, then submit your files to Gradescope, Codio or whichever platform your course is using.