jasonnoble / calculator

Calculator

1. Fork this repo
2. Clone your fork to your local machine
3. cd calculator
4. Add my repo as an upstream (git remote add upstream [email protected]:jasonnoble/calculator.git)
5. git fetch upstream
6. bundle

Open the editor of your choice.

Setup

You should work on a topic branch. Make sure you are on the main branch:

$ git branch
* main
$

Make sure you have the latest changes:

$ git fetch upstream
$ git reset --hard upstream/main

Create a topic branch:

$ git checkout -b attempt_1
Switched to a new branch 'attempt_1'
$ git branch
* attempt_1
  main
$

Overall Goals

1. Get comfortable with RSpec TDD process
2. Continue practicing Ruby
3. Get comfortable with staging and committing changes via git
4. You should commit at least at the end of each iteration. The more you commit, the better.

Running Guard

This repo has a number of automated tasks handled by the Guard gem. After creating your topic branch, run the following:

$ bundle exec guard --clear

This does a number of things:

• Runs bundle if you've changed your Gemfile
• Runs Rubocop to analyze your Ruby code for linting issues
• Runs RSpec

Leave this command running in your terminal. Whenever you change any code, guard will notice you saved changes and re-run the steps above.

Iteration 1

A Calculator represents a simple calculator

Attributes:

• None

Methods:

• total (returns the current total, 0.00 by default)

Steps:

1. Create a spec/calculator_spec.rb file
   1. Require the spec_helper
   2. Require './lib/calculator'
   3. RSpec.describe Calculator

Verify the following via your spec file:

• Creating a calculator requires no arguments
• You can ask a calculator for its total

Iteration Rubric:

• Rubocop returns no errors
• All tests are green
• Code coverage shows 100% test coverage

Iteration 2

A Calculator can add numbers

Methods:

• add(number)
  • Adds the number to the calculator's total

Special test cases (HINT: You should have an it block for each of these):

• Positive Numbers
• Negative Numbers
• Zero
• Decimal values (3.1415)

Iteration Rubric:

• Rubocop returns no errors
• All tests are green
• Code coverage shows 100% test coverage

Iteration 3

A Calculator can subtract numbers

Methods:

• subtract(number)
  • Subtracts the number from the calculator's total

Special test cases:

• Positive Numbers
• Negative Numbers
• Zero
• Decimal values (3.1415)

Iteration Rubric:

• Rubocop returns no errors
• All tests are green
• Code coverage shows 100% test coverage

Iteration 4

A Calculator can multiply numbers

Methods:

• multiply(number)
  • Multiply the calculator's total by the number

Special test cases (HINT: For all these, but the last one, you probably want to call calculator.add(2) before calling calculator.multiply(number):

• Positive Numbers
• Negative Numbers
• Zero
• Decimal values (3.1415)
• Calculators total is zero

Iteration Rubric:

• Rubocop returns no errors
• All tests are green
• Code coverage shows 100% test coverage

Iteration 5

A Calculator can divide numbers

Methods:

• divide(number)
  • Divides the calculator's total by the number

Special test cases:

• Positive Numbers
• Negative Numbers
• Zero (HINT: ...).to be_infinite)
• Decimal values (3.1415)
• Calculators total is zero

Iteration Rubric:

• Rubocop returns no errors
• All tests are green
• Code coverage shows 100% test coverage

Iteration 6

A Calculator can clear its total

Methods:

• clear
  • resets the total to 0.00

Iteration Rubric:

• Rubocop returns no errors
• All tests are green
• Code coverage shows 100% test coverage

Compare your results

After you've committed all your results via Git, you can check your work by running the following:

$ git diff upstream/complete

Do it again!

$ git checkout main
$ git fetch upstream
$ git reset --hard upstream/main
$ git checkout -b attempt_2

Repeat this process until you can do it quickly, without struggling.