ec2hx - EditorConfig to Helix

This is a CLI tool that translates an EditorConfig file to a project-specific configuration for the Helix editor.

Usage

1. Install using your preferred method:

   using binstall	cargo binstall ec2hx
   from source	cargo install ec2hx
   script, manual etc.	see release page

2. Run ec2hx in your project directory.

3. Start Helix / reload its config.

Upstream support

At the time of writing, Helix does not support EditorConfig. The maintainers don't want to add it in core, they want a plugin to handle it. However, the plugin system is still a work in progress. That's why ec2hx may be your best option at the moment.

Subscribe to the following issues and PRs to stay up-to-date with developments upstream:

• issue: Support for EditorConfig
• PR: Implement EditorConfig support
• PR: :trim to remove trailing whitespace
• issue: tracking issue: Switch to a scheme based config
• PR: Add Steel as an optional plugin system

Setting expectations

EditorConfig is much more flexible than the config of Helix, which means support is only partial. However, I believe the support is more than sufficient for "sane" configurations. This section describes in detail what is and isn't supported.

Supported keys:

• The keys end_of_line and insert_final_newline are only supported as a global setting, not per-language. That means the keys will only be translated to the Helix config if they appear in the global [*] section. If they appear in any other section, they will be ignored.

• The keys indent_style, indent_size and tab_width are supported per-language. However, they cannot be applied multiple times to the same language with different values.[^1] Therefore, sections that contain arbitrary globs are ignored. Only sections that look like they cleanly map to a set of file types are considered.

• The key max_line_length is supported, both globally and per-language. From the Helix documentation:

  Used for the :reflow command and soft-wrapping if soft-wrap.wrap-at-text-width is set

  (Use the CLI flag --rulers to add matching rulers.)

• The trim_trailing_whitespace key is supported. This is achieved with a built-in formatter that does the trimming. ec2hx configures Helix to call ec2hx trim-trailing-whitespace to format files.

  There is a limitation to this approach: ec2hx doesn't override any formatters or LSPs from the default or user Helix configuration, because they may already handle formatting. Unfortunately, you may not even have these installed, or some LSP may be installed but it doesn't support formatting. So, there are many false negatives where ec2hx won't automatically generate the formatter config for a language even if it might be safe.

  You can fix this by manually adding the below formatter config to either your user configuration (~/.config/helix/languages.toml) or the project-specific configuration (proj-dir/.helix/languages.toml). The latter is what ec2hx generates, but don't worry, it won't write over manual changes you have made if you run it twice.

  formatter = { command = "ec2hx", args = ["trim-trailing-whitespace"] }
  auto-format = true
  

• All other keys do not map to a config in Helix, so they will be ignored.

File processing:

The CLI only reads the toplevel .editorconfig. Supporting multiple .editorconfig files in a directory hierarchy leads to the same problem as arbitrary globs in section headers.[^1]

Glob expressions:

Only globs that look like they map cleanly to one or several file types are supported. The supported glob characters are: *, {}, []

Examples of supported section headers:

• [Makefile]
• [*.py]
• [*.{json,js}]
• [*.[ch]]
• [{*.{awk,c,dts},Kconfig,Makefile}] (nested {})

Globs which match against paths (i.e. which contain / or **) are not supported.[^1]

The following special characters aren't used in any config I'm testing against: ?, .., !, \. Sections which contain them in the header will be ignored. If you think one of these characters should be supported, please open an issue about it and ideally provide an example config that uses it.

File types:

As mentioned in the "supported keys" section, in Helix, indentation can only be configured for a specific language. If indentation is configured in the global EditorConfig section ([*]), the generated Helix config will have a section for all its supported languages. However, that's still not perfect! Languages that don't appear in the default languages.toml of Helix are left out. *.txt is a hardcoded exception and you can specify additional file globs to which the global config should apply via the CLI, for example:

ec2hx --fallback-globs '*.foo,*.bar'

If you have a file extension that appears explicitly in a section header, e.g. [*.foobar], the CLI should already generate an appropriate custom language definition for you.

Contributing

A good way to contribute is to provide an example EditorConfig file that you think could be handled better. You can open an issue about it or a PR adding it to the test_data/ directory next to the other examples. It will automatically be picked up by the snapshot tests (using insta).

[^1]: While indentation style can only be configured once per language in Helix, it is technically possible to define arbitrary custom languages. That means one could define one pseudo language for every different idententation style in the same project. Most language configuration options are copied from the real one, except for the file-types key, which is set to the desired glob. Out of morbid curiosity, I confirmed that this actually works. However, I'm not gonna implement that cursed idea. People working on projects with a deranged .editorconfig (cough linux kernel cough) can simply write that godforsaken Helix config by hand.