Misc: Line number preservation

Eex has no provisions for source maps, so we’ll have to emulate this by outputing EEx that matches line numbers exactly with the source .pug files.

div
  | Hello,
  = @name

  button.btn
    | Save

<div>
Hello,
<%= @name %>
<%
%><button class="btn">
Save<%="\n"%></button><%="\n"%></div>

Internal notes

Expug.Builder brings this output:

lines = %{
  :lines => 6,
  1 => [ "<div>" ],
  2 => [ "Hello," ],
  3 => [ "<%= @name %>" ],

  5 => [ "<button class="btn">" ],
  6 => [ "Save", "</button>", "</div>" ]
}

Expug.Stringifier will take this and yield a final EEx string. The rules it follows are:

• Multiline lines (like 6) will be joined with a fake newline (<%= "\n" %>).
• Empty lines (like line 4) will start with <%, with a final %> in the next line that has something.