SyntaxTree::ERB

Syntax Tree support for ERB.

Currently handles

• ERB
  • Tags with and without output
  • Tags inside strings
  • if, elsif, else and unless statements
  • blocks
  • comments
  • Formatting of the ruby-code is done by syntax_tree
• HTML
  • Tags with attributes
  • Tags with and without closing tags
  • Comments
• Vue
  • Attributes, events and slots using :, @ and # respectively
• Text output

Unhandled cases

• Please add to this pinned issue (#28) or create a separate issue if you encounter formatting or parsing errors.

Installation

Add this line to your application's Gemfile:

gem "w_syntax_tree-erb", "~> 0.11", require: false

I added the w_ prefix to avoid conflicts if there will ever be an official syntax_tree-erb gem.

Usage

Parsing

bundle exec stree ast --plugins=erb "./**/*.html.erb"

Format

bundle exec stree write --plugins=erb "./**/*.html.erb"

In code

require "syntax_tree/erb"

pp SyntaxTree::ERB.parse(source) # print out the AST
puts SyntaxTree::ERB.format(source) # format the AST

List all parsing errors

In order to get a list of all parsing errors (which needs to be fixed before the formatting works), this script can be used:

#!/bin/ruby

require "syntax_tree/erb"

failures = []

Dir
  .glob("./app/**/*.html.erb")
  .each do |file|
    puts("Processing #{file}")
    begin
      source = SyntaxTree::ERB.read(file)
      SyntaxTree::ERB.parse(source)
      SyntaxTree::ERB.format(source)
    rescue => exception
      failures << { file: file, message: exception.message }
    end
  end

puts failures

Development

Install husky:

npm i -g husky

Setup linting:

npm run prepare

Install dependencies and run tests:

bundle
bundle exec rake

Contributing

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

License

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