img_width_and_height.rb

# frozen_string_literal: true
module ThemeCheck
  # Reports errors when trying to use parser-blocking script tags
  class ImgWidthAndHeight < HtmlCheck
    severity :error
    categories :html, :performance
    doc docs_url(__FILE__)

    ENDS_IN_CSS_UNIT = /(cm|mm|in|px|pt|pc|em|ex|ch|rem|vw|vh|vmin|vmax|%)$/i

    def initialize(whitelist: [])
      @whitelist = whitelist || []
    end

    def on_img(node)
      width = node.attributes["width"]
      height = node.attributes["height"]

      record_units_in_field_offenses("width", width, node: node)
      record_units_in_field_offenses("height", height, node: node)

      return if node.attributes["src"].nil? || (width && height) || @whitelist.any? { |word| node.value.include?(word) }

      missing_width = width.nil?
      missing_height = height.nil?
      error_message = if missing_width && missing_height
        "Missing width and height attributes"
      elsif missing_width
        "Missing width attribute"
      elsif missing_height
        "Missing height attribute"
      end

      add_offense(error_message, node: node)
    end

    private

    def record_units_in_field_offenses(attribute, value, node:)
      return unless value =~ ENDS_IN_CSS_UNIT
      value_without_units = value.gsub(ENDS_IN_CSS_UNIT, '')
      add_offense(
        "The #{attribute} attribute does not take units. Replace with \"#{value_without_units}\"",
        node: node,
      )
    end
  end
end