rails whitespace syntax error

gistfile1.txt

# this one will not work, it creates a syntax error

class ArticlesController < ApplicationController
  def new
  end
  
  def create
    render plain: params[:article].inspect
  end
end

but this does work...

class ArticlesController < ApplicationController
  def new
  end

  def create
    render plain: params[:article].inspect
  end
end

<%- and -%> suppress leading and trailing whitespace
Is this required to not receive the unicode characters?