| Story points | 8 |
| Tags | tdd |
| Hard Prerequisites | |
| IMPORTANT: Please review these prerequisites, they include important information that will help you with this content. | |
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This a continuation of
PROJECT:
simple-calculator part 1
. If you haven’t done that yet then please do. At this point you should have a well tested add and multiply function.
This exercise will require a little OOP knowledge. Brace yourself.
Please test your code using jasmine.
Your directory structure should look like this.
>node_modules <---- make sure this is in your .gitignore
>spec
> support
- jasmine.json
- string_calculator_spec.js
>src
- string_calculator.js
- package.json
Your project is expected to be completed using pytest. You are expected to follow industry best practices in all things. This means that you need to have a directory structure that is in good shape. Please name your files and folders like this:
├── simple_calculator the package under test
│ └── calculator.py
├── requirements.txt installation requiremnts
├── setup.py installation script for the package under test
└── tests all package tests go in this directory
└── test_calculator.py
Please take a look at this topic to see an explanation of the required directory structure. [TODO] TOPIC: African Coding Network Syllabus
Update your tests so that they expect the add and multiply functions to be part of a class. Now make those tests pass.
For now on this document will just describe the features we need the Calculator to have. You need to figure out the tests and implementation yourself.
This is an extension of PROJECT: simple-calculator part 1 . In other words, previously implemented functionality should still work.
# this should still work
calculator_instance.add(3,5) # should return 8
calculator_instance.multiply(30,2) # should return 60
# and multiple arguments should work too
calculator_instance.add(3,5,2) # should return 10
The multiply functionality should also still work.
The calculator should have a function called last that returns the last result. Example usage:
calculator_instance.add(1,2)
calculator_instance.last() # should return 3
The add and multiply functions should allow "LAST" as a parameter.
Example usage:
calculator_instance.add(1,2)
calculator_instance.multiply("LAST",5) # should return 15
Allow the calculator to remember more stuff by implementing a set_slot function. The set_slot function should take a single number as an argument. That argument is called the slot number. Also implement get_slot for getting the value from a memory slot. Neither get_slot or set_slot should effect the output of last.
Example usage:
calculator_instance.add(1,2)
calculator_instance.set_slot(1)
calculator_instance.get_slot(1) # should return 3
calculator_instance.add(10,20)
calculator_instance.set_slot(2)
calculator_instance.get_slot(2) # should return 30
calculator_instance.add(100,200) # returns 300. The "last" value is updated
calculator_instance.get_slot(1) # should return 3
calculator_instance.get_slot(2) # should return 30
calculator_instance.last() # should return 300
The add and multiply functions should allow memory slots as parameters. If we were using memory slot 5 as an argument then we would represent it like this "SLOT_5".
Example usage: Following from the previous example:
calculator_instance.add(100,200) # returns 300. The "last" value is updated
calculator_instance.get_slot(1) # should return 3
calculator_instance.get_slot(2) # should return 30
calculator_instance.last() # should return 300 (just like before)
# THE FOLLOWING FUNCTIONALITY SHOULD WORK
calculator_instance.add("LAST",10) # should return 310 (= 300 + 10)
calculator_instance.add("SLOT_1",5) # should return 8 (= 3 + 5)
calculator_instance.multiply("SLOT_2",2) # should return 60 (= 30 * 2)