Better visualize differences in multiline strings

[MaksimMisin]

I had the same issue as #14 where my multiline string difference was not very readable:

I added a command line option --icdiff-multiline-string. Running the same test with pytest --icdiff-multiline-string -vv now returns a significantly more readable diff:

[hjwp]

thanks very much for the suggestion, and the PR! I think I'd defintely want something to improve string diffs.

It occurs to me - wouldnt' we maybe want to do this kind of non-pprint diff on any string? like, all the time, and then we wouldn't need a special CLI option?

i'd be keen to merge this without the CLI option, and just with an if that checks if both left and right are str.

also we'd need a test.

[MaksimMisin]

Thanks for the comments, I only added this option because I was afraid the pprint-ed strings were useful in certain situations.

LMK if you want more tests added.

[hjwp]

i don't quite understand what these asserts are doing?

[MaksimMisin]

That's to make sure that there're actually empty spaces instead of new lines after last characters on the line

before it looked like this:

so this test would fail

36 should be slightly above the actual size of these columns, with some margins in case icdiff implementation changes a bit.

[MaksimMisin]

Do you think you can merge the PR or is there anything missing?

[hjwp]

merged with thanks! I might try and find the time to fiddle with that test assertion to make it more readable, but otherwise all good for now! will throw up a new release when i get a moment...