Test-Driven Experiment

Create a directory called "test" to house your unit tests
Download the unit test template file to the "test" directory
Create a directory called "lib" to house your binary search code
Code up your tests and binary search function
Binary search specification:
Implement binary search in a function called binary_search that takes a sorted array as a parameter and a value. If the value occurs in the array, return the index at which it occurs in the array (if multiple occur, any index is fine). If it does not occur, return nil. You may assume that the value and the entries in the array support the comparison operators.
You should time how long each part takes you (writing tests and writing the function) regardless of which order you've been asked to do it. To do this, write down what time it is each time you start/end a new task.
- If you're writing the function first: write the function and test it the way you normally would. Only when you're happy with the functionality should you move on to writing the unit tests.
- If you're writing the unit tests first: write all the unit tests that you want to use before moving on to writing the function
Recall that to run unit tests in this framework you type:
```
ruby -I lib test/test_binary_search.rb
(assuming you're in the base directory)
```
When you're done coding, go up to the board and record your times.
Download the test script. Record on the chalkboard whether or not you passed all of the tests.