User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/38.0.2125.104 Safari/537.36 Steps to reproduce: Load the webpage included in the attached zip Open Developer Tools Go to the Debugger tab Reload the page Actual results: The sourcemap (batch.js.map) was request 196 times. Expected results: The sourcemap should have been requested once. I have noticed that this seems to be related to the complexity of the JS file being mapped. If you delete half of batch.js the number of requests that are made drops significantly.

There is this recent bug about sourceMap too: bug 1084534.

Thanks for the testcase! I can reproduce using current Nightly on OS X and couldn't find existing bugs about this.

And in FF33 or older?

Same in Firefox 33. Unless there's any indication it's a regression, I wouldn't bother testing older versions.

Seems like we are _always_ bypassing our cached source map requests inside `ThreadSources.prototype.sourceMap` (or, never checking the cache, only inserting into it) >.<

Comment on attachment 8512222 [details] [diff] [review] source-map-requested-200x.patch Review of attachment 8512222 [details] [diff] [review]: ----------------------------------------------------------------- ::: toolkit/devtools/server/actors/script.js @@ +5107,4 @@ > > /** > * Return a promise of a SourceMapConsumer for the source map for > * |aScript|; if we already have such a promise extant, return that. Yeah, we definitely weren't doing this: "if we already have such a promise extant, return that." The rest of the patch is just making a crappy test better.

Comment on attachment 8512222 [details] [diff] [review] source-map-requested-200x.patch Review of attachment 8512222 [details] [diff] [review]: ----------------------------------------------------------------- ::: toolkit/devtools/server/tests/unit/head_dbg.js @@ +606,5 @@ > + * @returns Promise<response> > + */ > +function reload(tabClient) { > + let deferred = promise.defer(); > + tabClient._reload({}, deferred.resolve); How come you are not using tabClient.reload() instead?

(In reply to Panos Astithas [:past] (overloaded, please needinfo) from comment #8) > Comment on attachment 8512222 [details] [diff] [review] > source-map-requested-200x.patch > > Review of attachment 8512222 [details] [diff] [review]: > ----------------------------------------------------------------- > > ::: toolkit/devtools/server/tests/unit/head_dbg.js > @@ +606,5 @@ > > + * @returns Promise<response> > > + */ > > +function reload(tabClient) { > > + let deferred = promise.defer(); > > + tabClient._reload({}, deferred.resolve); > > How come you are not using tabClient.reload() instead? Because reload doesn't take a callback :/