Contributing

Contribution to mime-types-data is encouraged in any form: a bug report, new MIME type definitions, or additional code to help manage the MIME types. There are a few DOs and DON'Ts for contributions.

Although mime-types-data was extracted from the Ruby mime-types gem and the support files are written in Ruby, the target of mime-types-data is any implementation that wishes to use the data as a MIME types registry, so I am particularly interested in tools that will create a mime-types-data package for other languages.

Adding or Modifying MIME Types

The Ruby mime-types gem loads its data from files encoded in the data directory in this gem by loading mime-types-data and reading MIME::Types::Data::PATH. These files are compiled files from the collection of data in the types directory.

[!WARNING]

Pull requests that include changes to files in data/ will require amendment to revert these files.

New or modified MIME types should be edited in the appropriate YAML file under types. The format is as shown below for the application/xml MIME type in types/application.yml.

- !ruby/object:MIME::Type
  content-type: application/xml
  encoding: 8bit
  extensions:
    - xml
    - xsl
  references:
    - IANA
    - RFC3023
  xrefs:
    rfc:
      - rfc3023
  registered: true

There are other fields that can be added, matching the fields discussed in the documentation for MIME::Type. Pull requests for MIME types should just contain the changes to the YAML files for the new or modified MIME types; I will convert the YAML files to JSON prior to a new release. I would rather not have to verify that the JSON matches the YAML changes, which is why it is not necessary to convert for the pull request.

If you are making a change for a private fork, use rake convert:yaml:json to convert the YAML to JSON, or rake convert:yaml:columnar to convert it to the new columnar format.

Updating Types from the IANA or Apache Lists

If you are maintaining a private fork and wish to update your copy of the MIME types registry used by this gem, you can do this with the rake tasks:

$ rake mime:iana
$ rake mime:apache

A Note on Provisional Types

Provisionally registered types from IANA are contained in the types/*.yaml files. Per IANA,

This registry, unlike some other provisional IANA registries, is only for temporary use. Entries in this registry are either finalized and moved to the main media types registry or are abandoned and deleted. Entries in this registry are suitable for use for development and test purposes only.

Provisional types are rewritten when updated, so pull requests to manually customize provisional types (such as with extensions) are considered lower priority. It is recommended that any updates required to the data be performed in your application if you require provisional types.

The Release Process

The release process is almost completely automated, where upstream MIME types will be updated weekly (on Tuesdays) and be presented in a reviewable pull request. Once merged, I need to perform a release and the update is complete.

If performing a manual release outside of the update cycle, the IANA updates should be performed manually.

  1. Review any outstanding issues or pull requests to see if anything needs to be addressed. This is necessary because there is no automated source for extensions for the thousands of MIME entries. (Suggestions and/or pull requests for same would be deeply appreciated.)

  2. bundle install

  3. Review the changes to make sure that the changes are sane. The IANA data source changes from time to time, resulting in big changes or even a broken step 4. (The most recent change was the addition of the font/* top-level category.)

  4. Write up the changes in CHANGELOG.md. If any PRs have been merged, these should be noted specifically and contributions should be added in Contributing.md.

  5. Commit the changes and push to GitHub.

  6. bundle exec rake release VERSION=newversion

This is based on an issue #18.

Help Wanted

I want to automate this even further. I am not switching from Hoe for release management, so the use of rubygems/release-gem requires some care (perhaps by exporting VERSION=$(rake version) to the job), but assistance in getting this action going for an automated release would be greatly appreciated.