Credit Check

This is a starter repo for Credit Check, a Turing School Back End Mod 1 project described in more detail here.

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Project Description:

1. From the rightmost digit, which is the check digit, moving left, double the value of every second digit if product of this doubling operation is greater than 9 (e.g., 7 * 2 = 14), then sum the digits of the products (e.g., 10: 1 + 0 = 1, 14: 1 + 4 = 5).
2. Take the sum of all the digits
3. If and only if the total modulo 10 is equal to 0 then the number is valid

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Pseudocode:

1. Define credit card number
2. Find a method that splits the credit card number (hint: this is a string)
3. Convert string to array
4. Find a method that reverses the return value of the split number (array)
5. Double every other digit of the array
6. Determine if the doubled digit is greater than 9
7. For digits greater than 9, sum the digits
8. Sum the results
9. Run a method that divides the summed number by 10,

• if the modulo = 0, then the card is valid,
• if modulo != 0, then the card is invalid

10. Output a message indicating whether the card number is valid or invalid

• If it is valid, print "The number is valid!"
• If it is invalid, print "The number is invalid!"

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Expectations

Ruby Syntax & Style

• Naming follows convention (is idiomatic)
• Ruby methods used are logical and readable
• Code is indented properly
• Code does not exceed 80 characters per line

Breaking Logic into Components

• Code is effectively broken into methods & classes
• May break the principle of SRP

Test-Driven Development

• Each method is tested
• Functionality is accurately covered
• Tests implement Ruby syntax & style
• Balances unit and integration tests
• Evidence of edge cases testing
• A test RakeTask is implemented

Functionality

• Application meets all requirements (extension not req’d)

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Rake Task test file

Rake task test code taken from this website:

https://medium.com/@jaeger.rob/a-simple-ruby-rakefile-for-tests-149a7b783c52