Adding support for enums

Michael J. Ryan tracker1 at
Sun Jun 10 03:26:21 UTC 2018

Just use symbols for your action type

On Sat, Jun 9, 2018, 14:21 Doug Wade <douglas.b.wade at> wrote:

> Hello friends!
> I had a bug the other day on my team.  We use redux <> to
> manage the state on our application <>, which
> is maintained by a large team.  In Redux, there are actions, which are
> strings, that get passed to a reducer, which mutates the states.  My
> coworker and I inadvertently added the same action name, "LOADING" on the
> same page, but in two different files.  This led to a bug when both my
> modal and his search results would be loading at the same time, but since
> they were never both visible, we didn't catch the bug.  My coworker
> refactored his feature, and broke my feature, such that rather than
> displaying a spinner, we went straight to an empty results page, even when
> there were results.
> In other languages, like the language I use most at work, Java, we would
> instead use a language construct called an enum
> <> in this situation so that
> the two different sets of actions weren't equal to each other.  I did some
> research into some previous discussions on this
> <> topic, and it seems like the
> discussion has been broadly in favor of it. I also noted that enum is a reserved
> keyword
> <>,
> which indicates some intention to add enums to the language.
> As such, I've spent some time working on a proposal
> <> for adding enums
> to ECMAScript. It is very heavily based on the work by rauschma
> <>, stevekinney
> <> and rwaldron
> <>. I wasn't sure if
> I was using all the right words when writing the proposal, so to help
> express myself better, I also spent some time writing a babel plugin
> <> that
> uses a polyfill <> against
> which I've written a small test suite
> <> (if you would like to run
> them, you'll need to link the polyfill and the babel plugin into the
> tests). Please do not take these as any indication of "done-ness", I wrote
> them to understand how I would expect an enum in javascript to behave, and
> am willing and eager to make changes as I get suggestions. I do, however,
> feel I have done as much as I can on my own, and would like help in
> considering the proposal, especially whether it contains any footguns,
> undefined behavior, or things that would be surprising to newer developers,
> and helping me identify what work is to be done to make this a "real"
> proposal.
> All the best,
> Doug Wade
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