counsel-jq

Live queries against JSON and YAML data

TL;DR: If you’re a fan of jq or yq and you’re using Emacs Ivy/Swiper/Counsel, then this package is for you.

Longer version: If you are working with complex nested JSON (or YAML) structures, you are probably familiar with jq (or yq) which is like sed for JSON data and great at what it does. However, being a command-line tool like sed, the feedback for writing queries and seeing their results is a discrete process and not live.

Cool. That might even be a feature that would draw in new Emacs users!

(alphapapa during the melpa submission)

When working with Emacs, we are used to good auto-completion and live feedback. Formerly, this was mostly done with static input, but with modern completion frameworks like Ivy, this can be done with dynamic inputs, as well.

counsel-jq is a package with which you can quickly test queries and traverse a complex JSON and YAML structure whilst having live feedback. Just call M-x counsel-jq in a buffer containing JSON or YAML, then start writing your jq or yq query string and see the output appear live in the message area. Whenever you’re happy, hit RET and the results will be displayed to you in the buffer *jq-json*.

Demo:

Configuration

To define whether you want to use yq over jq as processing tool, call M-x customize and set counsel-jq-command to yq.

In the same manner you can define the name of the results buffer by customizing the counsel-jq-buffer variable.

Lastly, by default, the results buffer *jq-json* buffer will have the major mode js-mode, but that can be customized with the counsel-jq-json-buffer-mode variable if you prefer json-mode, rsjx-mode or any other mode.

EmacsConf 2020 talk on counsel-jq

On [2020-11-29 Sun], Zen Monk Alain M. Lafon (@munen) gave a talk at EmacsConf 2020 introducing counsel-jq. There’s a video recording with explanations and demos behind this complementary blog post: https://200ok.ch/posts/2020-11-30_emacsconf_traverse_complex_json_structures_with_live_feedback_with_counseljq.html