April 2020 Monthly Update

By Alyssa Parado


Apr 1-15

Ring 2.0.0-alpha1 has been released, with the adapter and servlet utility functions supporting both Ring 1 and Ring 2 keys by default, though there is also an option for forcing a particular version.

Based on community feedback, the Ring 2.0 request and response headers have been changed to be closer to the standard laid out in the Ring 1.x specifications.

I’ve begun setting up a project using the JMH benchmarking harness to compare Ring 1 with Ring 2 performance, particularly around building the request map. Higher level tests with ApacheBench proved too imprecise to draw meaningful conclusions, as the variance between results was higher than any measurable difference between Ring versions.

I’ve also been reconsidering some of the ideas around adding request and response protocols to Ring as a way of supplimenting map key access. Initially I considered them out of scope, as they’re a performance enhancement, however they could also be used as a compatibility mechanism for middleware that supports both Ring 1 and 2 formats.

Apr 16-30

I’ve constructed a JMH-based benchmarking project for Ring 1.8 and Ring 2.0, in order to get a better idea of the relative performance of both versions, specifically around converting to and from Java servlet objects. I’ve written up the initial findings and published them as a comment on the Ring 2.0 GitHub issue.

I’ve also been fixing various smaller issues with Ring 1.8.0, and should be ready to release 1.8.1 by the end of the day.

Work on websocket support has been on pause while performance and compatibility concerns were investigated, but that work is now ready to be resumed. Work on Ring 2.0 will continue over the next few months, and further alphas will be released to allow community feedback and testing of new features.

The first stable version of Ring 1.0 was released a little over 8 years ago. With a little luck, Ring 2.0 will last even longer.


Apr 1-15


The debugger has been released! Documentation for the debugger was written and published that covers the existing functionality and lists current and upcoming features.

Since then, I’ve added step over, step in, and step out functionality as well as annotations in the editor to show the value of the current form as execution moves to each breakpoint. I’ve updated the docs to reflect these changes as well as made some general improvements to the docs.

I’m currently working on polishing the latest changes and then will release them along with the updates to the docs.


The Calva docs have a new look and a new home! We switched to using mkdocs for building our docs and are using the material theme.

Apr 16-30


I’ve added a command to instrument functions for debugging as an alternative and more convenient method than adding #dbg reader tags to the code file. I’ve also added editor decorations to visually indicate which functions are instrumented. The instrumented function definitions as well as the usages gain a top and bottom border and a background. clj-kondo is used as a JVM library to get the var definitions and usages, and this data is matched up with cider-nrepl’s debug-instrumented-defs response data to create the decorations on document change.

The instrument command and decorations features were released and I’ve started working on displaying structured values, for locals, in the VS Code debugger side pane (currently non-primitives are shown as strings). This should allow a user to “drill down” into a structured value like a map or collection.


Apr 1-30

Reagent 1.0.0-alpha1 is out and contains implementation of both creating React function components from Reagent components and options. The default is still to create class components by default, to ensure compatibility, but an option can be used make function components the default.

After the last update, I had pretty much everything ready, but I wanted to change the API a bit before first release. The first implementation of options had one problem related to caching, as different options could result in different results but the cache was shared. This was one of the reasons I wanted to create “Compiler” object which is created using the options. This object can hold the cache (or unique key for caches) and is implemented as a reified protocol. This object currently holds the implementation for a few Reagent internal functions, most importantly as-element, and in future the function or macro creating this object from options map, can generate different code for this (and other) methods.

Implementing and getting all the tests passing with this approach took quite long, but I finally got everything working. After finishing the code, I added some new documentation pages and a new example showing making Function components default and using Hooks with Reagent, and created the first release for testing.

Based on the comments from users, I’ve already added two more “shortcuts” to Reagent: :f> to create Function Reagent component (using the default options), and :r> to use React components without properties conversion done by :> and adapt-react-class.

Additionally I’ve followed latest developments in ClojureScript compiler, and added new test environment for Reagent, using the new :bundle compilation target. This target generates JS tooling compatible output. This output can be passed to Webpack, or for testing, Karma.


April 1-30


April 1-30

This month included work finishing up the migration to AWS, including:

I then started on improving security. The work here was focused on adding a deploy token feature. This was released in early May, but 90% of the work was completed in April.

I also fixed an issue where the cookies weren’t being set as secure.