Fix insert action for swiper-isearch

[dustinpaluch]

swiper-isearch passes a buffer position to ivy--action-insert. The existing insert action throws an error. #2929
This change assumes numbers passed to ivy--action-insert are valid buffer positions in the current buffer, and converts them to a string containing the line that buffer position is on, allowing insert to do the right thing.

make compile - check for new compilation warnings ✅ 
make deps - install dependencies for testing ✅ 
make test - check for failing tests ✅ 
make checkdoc - check documentation guidelines ✅ 

[basil-conto]

Thanks! This continues cleaning up the sad state of regressions between swiper and swiper-isearch that I also tried improving in #2913 and #2914.

This change assumes numbers passed to ivy--action-insert are valid buffer positions in the current buffer, and converts them to a string containing the line that buffer position is on, allowing insert to do the right thing.

Ivy is meant to be a low-level generic completion framework, and Swiper simply a client thereof. I think it's therefore better if Ivy remain as unaware of Swiper implementation details as possible, and this issue be fixed on the Swiper side instead.

That calls for a swiper-isearch override of the i (insert) action. Have a look at #2914 to see how I did this for the o (default) and w (copy) actions; you may be able to reuse some of the functions there. Thanks.

[dustinpaluch]

Looking at the implementation of swiper-isearch-action-copy, it looks like it only copies the portion of the line that is the exact match of your swiper-isearch input, which makes sense.

So it would make sense for an insert action to do the same, but that's not really the feature I was trying to fix/implement.

My use case is that after finding a line via swiper-isearch, I want to insert that entire line where I started the search from. "You should use regular swiper then"... yes. But I use swiper-isearch as my default search function because I want both the minibuffer candidate list for browsing results as well as the ability to C-s to other matches on the same line. And I don't want to have to think about whether I want to do a full line insert before invoking either swiper or swiper-isearch. Nor do I have the keybinding real-estate to have both functions on easily invokable/high-traffic keys.

So I guess this is just an idiosyncrasy of my workflow, and I should just add my own custom action to swiper-isearch in my own config.

[dustinpaluch]

@basil-conto , thanks for the feedback! Here's a new attempt mirroring your copy action, staying consistent with only inserting the match-string instead of the entire line which my first attempt did.

[abroekhof]

How's this look to get checked in? Would be nice to have this functionality!

[buhtz]

I assume my problem (#3006) depends on the problem that RP try to fix. Would be great if this could be merged.

[basil-conto]

Thanks!

[basil-conto]

Sorry for the delay in merging this.

Please have a look at my followup change for supporting swiper-goto-start-of-match and swiper-isearch-backward, and let me know if anything is amiss: b69f78f