count-down-loop diagnostic misses cases

[carsakiller]

The problem

The count-down-loop diagnostic does not warn all the time when the loop end cannot be reached due to it being less than the loop start.

-- warns
for i=10, 1 do end

-- does not warn
for i=100, 10, 1 do end

There is also no count-down-loop equivalent for loops that count up but never reach the end of the loop:

-- does not warn
for i=1, -10 do end

--does not warn
for i=-10, 100, -1 do end

The solution

I think the count-down-loop diagnostic should be renamed to loop-never-ends. It can then be used for all of the cases above.

Originally posted by @carsakiller in #1362 (reply in thread)

[sumneko]

It should be loop-only-once instead of loop-never-ends.

However this check is used for preventing missing the step. If the user remembers to write the step, he will not write it wrong.