From:  Thaddee Tyl <>
Date:  03 May 2013 23:28:58 Hong Kong Time

Dynamic sourcemaps


I dug into the state of dynamic sourcemaps again today. I am unsure
about what the acknowledged progress of it is. However, there are two
points I would like to make on both Firefox' and Chrome's
I should note that in both cases, I used the bleeding edge, that is,
Canary and Nightly.

Firstly, the following URL is that of a webpage which attempts to use
dynamic sourcemaps:

The source is URL-encoded in the JSON source map, which is itself
encoded in a data URL. It makes use of the sources / sourcesContent
It simply does not work in Chrome: the source goes undetected.
Firefox notices the source, but never loads its content, showing
"Loading..." in the editor instead.
In both cases, I'd love to know what is going on.

Which leads me to my second point. I clearly have the intention to use
sourcemaps (it is quite easy to detect), yet no error shows up,
neither in Firefox, nor in Chrome. Even if not spec'ed, some errors
should show up in the developer tools, if only for library /
transpiler authors, but also for the general developing public: if the
sourcemap generator fails, the developer should know why, to be able
to report the error to the transpiler author.

(I do believe that errors should be spec'ed, though.)