From:  "Fitzgerald, Nick" <>
Date:  04 Jun 2014 02:02:55 Hong Kong Time

Re: Adding media type for sources to source maps


On 6/3/14, 10:19 AM, John Lenz wrote:
> I think "sourcesDefaultMediaType" and "sourcesMediaType" rather than 
> overloading sourcesMediaType.

I'm not sure I follow, can you expand?

>  As these are optional, generally useful, and we can add them without 
> changing the meaning of any existing source maps, we can add this to 
> the spec without problem. 

Yup, not breaking old source map parsers is definitely a requirement.

Every proposal in this thread has fulfilled this, unless I'm missing 

>  As long as we can agree on the form.


> Regarding size, Brian and Google Web Toolkit team have been pretty 
> successful in reducing the size of the source maps by removing 
> information that isn't useful to the debuggers (reducing them to 
> basically line mappings rather than token maps).   This is controlled 
> by the source map producer but can be done as a post-process.  But 
> that is a discussion for another thread.

I did the same thing in [0] but my goal was speeding up the time it 
takes to generate a source map.


> If we do add this, I would like to document common "known" media types 
> in the spec appendix (CSS,HTML,JS,CoffeeScript,TypeScript,SASS,etc) to 
> reduce the ambiguity that naturally comes along with using media types.

Sounds good to me.