Indeed,

Appears that the pixel_size is a "double" for the example tests, but the random tests are 2 integers separated by a space... Does not appear to be solvable at the moment. The space appears to be in error going by the test comment.

[1] "Testing for wall_length = 7731, pixel_size = 715"
[1] 7731
[1]  7 15
[1] "integer"

R tests are fine, not a kata issue. Read the description again.

[R problem]
The author seems to have failed with this kata, the list provided doesn't match with the expected answer...
The random cases don't work !

Problem for the R version.
In random test, the pixel_size is in multiple part (split in word of size two), impossible to corectly launch the random test part
Thanks