Funny to read this three years later.
I did exactly the same thing, for exactly the same reason.

Is it because the first piece here isn't minimal?

Duplicate issue. Closing.

Fixed

the second one IS expected. The first one cannot be, because of the requirements:

You are given an ASCII diagram, containing minus signs "-", plus signs "+", vertical bars "|" and whitespaces " ". Your task is to write a function which will break the diagram in the minimal pieces it is made of.

For this shape:

+-----------------+
|                 |
|+---+------------+
||   |
||   |
||   |
|+---+------------+
|                 |
+-----------------+"

I think the below 2 sub-shapes should also be accetable?

+-----------------+
|                 |
|    +------------+
|    |
|    |
|    |
|    +------------+
|                 |
+-----------------+

and

+---+
|   |
|   |
|   |
+---+

Can you tell me why this isnt the case?

re-ranked to 6 kyu

All good.

Suggestion: you could increase the number of tests so that inefficient solutions aren't valid. But this is just a suggestion.

This has been fixed, you may retry the kata if you wish (as your solution doesn't work anymore).

looks perfect. I'll take a look at the implementation (mine!) tomorrow.

I now compare my computed cost with user's one so it still gets evaluated.
I updated the sample tests, and will update the part of the description I forgot about after tinkering with closures, it should be correct after I re-publish the kata.

Ah ok, you did actually completely change the output... Why did you remove the final cost from the output? (since this wasn't that part that caused trouble ;) )

• you forgot to update the description
• same for the sample tests

Does your function return a tuple instead of list? Because that would be a problem (added conversion in case this happens). If it is not the case, I have no idea why would this happen.

Warning, you made an error in your modifications, the kata isn't currently completable:

Traceback:
   in <module>
   in assert_path
AttributeError: 'tuple' object has no attribute 'pop'

some reading, second part, about the closure. ;)