TDDExerciseAccoutingSystem

This repository is used to practice TDD (Test-Driven Development)programming. Here list different iterations for people to implement unit test case and production code step by step.

Iteration #1

For a single account with one main line and any optional "additional lines", calculate a monthly phone bill based on:

• Plan Type — Gold or Silver
• Additional line rate (shown below)

Plan Rates

Here are the rates for each plan type:

Plan	Basic Monthly Rate	Rate per Additional Line
Gold	49.95	14.50
Silver	29.95	21.50

Examples:

Plan	Number of Lines	Expected Bill
Gold	1	49.95
Gold	2	14.50 + 49.95 = 64.45
Silver	1	29.95
Silver	3	(2*21.50) + 29.95 = 72.95

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Iteration #2

For a single account, calculate a monthly phone bill, including excess minutes based on:

• Plan Type — Gold or Silver
• Number of Lines
• Excess Minutes — minutes used in excess of the included minutes

Plan Rates

Here are excess minutes rates for each plan type:

Plan	Basic Monthly Rate	Included Minutes
Gold	49.95	1000
Silver	29.95	500

Examples

Plan	Minutes Used	Number of Lines	Expected Bill
Gold	999	1	49.95
Gold	1000	1	49.95
Gold	1001	1	49.95 + 0.45 = 50.40
Gold	1010	1	49.95 + (10 * 0.45) = 54.45
Silver	499	1	29.95
Silver	500	1	29.95
Silver	520	1	29.95 + (20 * 0.54) = 40.75

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Iteration #3

Calculate Family Discount

Families that have a main line and 3 or more additional lines qualify for Bill's "family discount."

For example, if Aunt Martha has 1 main line and 2 additional lines for her good-for-nothing sons, Ned and Ted, she doesn't qualify for Big Bill's family discount. If Aunt Martha got a 3rd additional line (maybe for her estranged sister, Bertha), that 3rd line would qualify for the "family" discount and only cost Martha an additional fee of $5.00 per month instead of the Gold plan's additional line rate of $14.50 per month or the Silver plan's additional line rate of $21.50 per month.

Please calculate a monthly phone bill for families that qualify or don't qualify for the family discount.

Examples

Plan	Minutes Used	Number of Lines	Expected Bill
Gold	<1000	2	49.95 + 14.50 = 64.45
Gold	<1000	3	49.95 + (2 * 14.50) = 78.95
Gold	<1000	4	49.95 + (2 * 14.50) + 5.00 = 83.95
Silver	<500	4	29.95 + (2*21.50) + 5.00 = 77.95
Silver	<500	5	29.95 + (221.50 + (25.00)) = 82.95