I edited the description to clarify that if m and n are equal, the range is empty and the result should be 0. I added tests in the Javascript and CoffeeScript test suites to verify that solutions do return 0 when m and n are equal.

Please excuse my initial reaction to reading the problem. You are correct that it is easy to be negative and not easy to provide more constructive feedback.

There are plenty of ways to state the prime number problem. You need to describe the type of input that you will be providing in your test case.

"Write a function that returns a boolean value representing whether or not a given integer is prime. A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself.

For example:

PrimeTest(1); //false
PrimeTest(13); //true
PrimeTest(-5); //false
"

Stating "given integer" says that the input will be an integer, but nothing further. Also, devided should be divided.

I'm sure the author would appreciate it more if you suggested a better description rather than just harshly criticising and being very negative about it. It is easy to be critical from your armchair.

Terrible description. Should rewrite altogether

No statement of what happens when m and n are equal.