This gem is a simple script to download all the custom emoji in a Slack workspace and upload them to a Mattermost instance.
$ git clone https://git.simulacrum.party/simulacrumparty/slack_mattermost_emoji.git
$ cd slack_mattermost_emoji
$ bundle
$ cp .env.sample .env
Fill in the relevant values in .env and you should be all set!
(requires Ruby and Bundler to be installed)
$ bin/slack-mattermost-emoji
Running the test suite will upload actual files to your actual Mattermost instance.
$ rspec
The gem is available as open source under the terms of the MIT License.