Patches

[Rich-Harris]

Follow-up to #26. This is a complete rethink of how magic-string works – rather than progressively overwriting a string with new content, and keeping track of mappings between the original and the result, this version accumulates edits non-destructively.

This allows us to loosen some of the restrictions on where edits (and slices) can be made, and paves the way for new functionality such as that sought in #26 and (possibly) #14. It may also be more performant.

Breaking changes: magicString.locate(...) and magicString.locateOrigin(...) are deprecated. These methods were used internally but are now no longer needed – if an external consumer of the library is using those methods it's probably for a bad reason (such as magic-string not having other methods that are necessary). Having said that, if it turns out they do have valid uses, we could reimplement them.

• compare performance characteristics of this versus current version
• update docs
• test out with other libraries that use magic-string, to ensure they continue to work
• some of the code is a bit woolly – try and tidy it up