A way to just get the inline additions / deletions?

[mmrZHdK]

If you diff two strings that rarely have newlines or none at all, how would you avoid duplicating a lot of text in the unchanged part? Especially in the HTML output? Any hints on this?

For example:

"This is my string which has a lot of some text but no newlines and only a very small fraction of information is changed"

[samg]

There's isn't a clear cut way to do that with the current functionality, though there's some extensibility built in to create custom output formats. I do think there's a common desire for this, for folks looking to diff minimized JS, CSS, etc. so I'd happily review a pull request if you find a generic way to do this.

In terms of addressing your problem in the short term I can see two reasonable ways you could accomplish this in the short term.

1. Preprocess your input. For example, assuming this is minimized js you're diffing, convert all the ; to ;\n so that you can see line-by-line diffs. This stackoverflow answer talks a bit more about this approach.
2. Postprocess the output. It might also be resonable to take diffy's html output and scan it for the <strong> tags that represent inline changes. This isn't super clean but depending on your use case it could be part of an acceptable solution.