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. New features should be proposed and discussed in an issue.

Before contributing patches, please read the Licence.

MIME::Types data is governed under the Contributor Covenant Code of Conduct.

Code Guidelines¶ ↑

I have several guidelines to contributing code through pull requests:

• I use code formatters, static analysis tools, and linting to ensure consistent styles and formatting. There should be no warning output from test run processes. I use Standard Ruby.

• Proposed changes should be on a thoughtfully-named topic branch and organized into logical commit chunks as appropriate.

• Use Conventional Commits with my conventions.

• Versions must not be updated in pull requests unless otherwise directed. This means that you must not:

• Modify VERSION in lib/mime/types/data.rb. When your patch is accepted and a release is made, the version will be updated at that point.

• Modify mime-types-data.gemspec; it is a generated file. (You may use rake gemspec to regenerate it if your change involves metadata related to gem itself).

• Modify the Gemfile.

• Type updates may only be performed on the YAML files in types/. This means that no files may be modified in data/. Any changes to be captured here will be automatically updated on the next release.

• Documentation should be added or updated as appropriate for new or updated functionality. The documentation is RDoc; mime-types-data does not use extensions that may be present in alternative documentation generators.

• All GitHub Actions checks marked as required must pass before a pull request may be accepted and merged.

• Add your name or GitHub handle to CONTRIBUTORS.md and a record in the CHANGELOG.md as a separate commit from your main change. (Follow the style in the CHANGELOG.md and provide a link to your PR.)

• Include your DCO sign-off in each commit message (see LICENCE).

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 run conversion 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 and rake convert:yaml:columnar to convert it to the default 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.

Commit Conventions¶ ↑

MIMe::Types has adopted a variation of the Conventional Commits format for commit messages. The following types are permitted:

| Type | Purpose | | ——- | —————————————————– | | feat | A new feature | | fix | A bug fix | | chore | A code change that is neither a bug fix nor a feature | | docs | Documentation updates | | deps | Dependency updates, including GitHub Actions. | | types | Manually contributed MIME::Types |

I encourage the use of Tim Pope’s or Chris Beam’s guidelines on the writing of commit messages

I require the use of git trailers for specific additional metadata and strongly encourage it for others. The conditionally required metadata trailers are:

• Breaking-Change: if the change is a breaking change. Do not use the shorthand form (feat!(scope)) or BREAKING CHANGE.

• Signed-off-by: this is required for all developers except me, as outlined in the Licence.

• Fixes or Resolves: If a change fixes one or more open issues, that issue must be included in the Fixes or Resolves trailer. Multiple issues should be listed comma separated in the same trailer: Fixes: #1, #5, #7, but may appear in separate trailers. While both Fixes and Resolves are synonyms, only one should be used in a given commit or pull request.

• Related to: If a change does not fix an issue, those issue references should be included in this trailer.

The Release Process¶ ↑

The release process is completely automated, where upstream MIME types will be updated weekly (on Tuesdays) and be presented in a reviewable pull request. Once merged, the release will be automatically published to RubyGems.

With the addition of trusted publishing, there should no longer be a need for manual releases outside of the update cycle. Pull requests merged between cycles will be released on the next cycle.

If it becomes necessary to perform a manual release, 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. Ensure that the VERSION in lib/mime/types/data.rb is updated with the current date UTC.

6. Run rake gemspec to ensure that mime-types.gemspec has been updated.

7. Commit the changes and push to GitHub. The automated trusted publishing workflow will pick up the changes.

This list is based on issue #18.