cj / erb-formatter

Format ERB files with speed and precision

ERB::Formatter 🪜

Format ERB files with speed and precision.

Features:

• very fast
• attempts to limit length (configurable)
• tries to have an output similar to prettier for HTML
• indents correctly ruby blocks (e.g. if/elsif/do/end)
• designed to be integrated into editors and commit hooks
• gives meaningful output in case of errors (most of the time)
• will use multiline values for class and data-action attributes

Roadmap:

• extensive unit testing
• more configuration options
• more ruby reformatting capabilities
• JavaScript and CSS formatting
• VSCode plugin
• fix spaces after attribute equal signs instead of complaining

Installation

Add this line to your application's Gemfile:

$ bundle add erb-formatter

Or install it yourself as:

$ gem install erb-formatter

Usage

From the command line

Update files in-place:

$ erb-format app/views/**/*.html.erb --write

or use stdin/stdout (useful for editor integrations):

$ echo "<div       > asdf  <% if 123%> <%='foobar'%> <%end-%>  </div>" | erb-format --stdin
<div>
  asdf
  <% if 123 %>
    <%= 'foobar' %>
  <% end -%>
</div>

Check out erb-format --help for more options.

From Ruby

require 'erb/formatter'

formatted = ERB::Formatter.format <<-ERB
<div        >
            asdf
                  <% if 123%>
                      <%='foobar'%> <%end-%>
           </div>
ERB

# => "<div>\n  asdf\n  <% if 123 %>\n    <%= 'foobar' %>\n  <% end -%>\n</div>\n"
#
# Same as:
#
#   <div>
#     asdf
#     <% if 123 %>
#       <%= 'foobar' %>
#     <% end -%>
#   </div>

With lint-staged

Add the gem to your gemfile and the following to your package.json:

"lint-staged": {
  // …
  "*.html.erb": "bundle exec erb-format --write"
}

As a TextMate plugin

Create a command with the following settings:

• Scope selector: text.html.erb
• Semantic class: callback.document.will-save
• Input: document → text
• Output: replace document → text
• Caret placement: line-interpolation

#!/usr/bin/env bash

cd "$TM_PROJECT_DIRECTORY"
bundle exec erb-format --stdin-filename "$TM_FILEPATH" < /dev/stdin 2> /dev/stdout

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/nebulab/erb-formatter.

License

The gem is available as open source under the terms of the MIT License.