[feature request] assertEquals multiline string diffs

[andykais]

currently assertEquals will pretty print js object differences

but will show multiline string diffs as a single blob

The actual diff here is pretty much unreadible so I often end up writing the changes to a file and using git diff or the diff command to see the actual changes.

It would be great if assertEquals could show multiline string diffs in a similar manner to git diff

[lowlighter]

Do you mean something like git diff --word-diff ?

[andykais]

@lowlighter sure, but even a normal git diff would be an improvement. That is a multiple line string comparison (see the \n characters), but it reads as a single line comparison

[ebebbington]

I too think this would be nice to have, there's plenty of times where im wanting to assert a very large string ie help output from a cli - i have to just sift through every character and compare if the first line in the expected ends with the same character as the actual, then the same for line 2, and so on 😆

Granted i'm the on with massive strings so i brought it upon myself, but would be nice to have multiline string diffs (eg not escaping newlines or colour encoding)

[lowlighter]

So I made a prototype for both multi-lines/words diffs which render like below:

Basically if both operands are string, a custom string tokenizer is called before entering diff() function.

I'm not sure how to auto-switch from multi-lines diff to word-diff yet though 🤔
I think words is more readable when few words are edited so maybe a threshold to switch to multi-lines based on number of words edited would be the best.

@ebebbington Not escaping colours seems a bit tricky, since the diff renderer currently uses colors, not sure what would be the right way to do this