Fixed sourceMapBasepath bug as the option had no affect on the sourceMapURL value.

[barnabycolby]

As discussed in #1781, the sourceMapBasepath option has no affect on the sourceMapURL value output in the css file. This pull request fixes the issue.

There do not currnetly appear to be any tests for the sourceMapURL CSS appendage.

[matthew-dean]

@barnabycolby The tests for source maps are currently pretty slim in Less. Can you articulate and demonstrate the original issue more clearly, especially since #1781 was closed? What output was expected and what Less was generating? And then how this PR affects that (in the form of a test)?

[barnabycolby]

@matthew-dean The --source-map-basepath option is supposed to remove the given basepath from the start of the source map output path, and more precisely, from the sourceMappingURL value found at the bottom of the compiled CSS. For example, running the following:

node bin/lessc --source-map=foo/bar.css.map bar.less bar.css

results in the following CSS appendage in bar.css

/*# sourceMappingURL=foo/bar.css.map */

Adding the --source-map-basepath option should allow us to remove the foo/ prefix. So running

node bin/lessc --source-map=foo/bar.css.map --source-map-basepath=foo bar.less bar.css

should result in the following CSS appendage in bar.css

/*# sourceMappingURL=bar.css.map */

However, the --source-map-basepath option did not cause the basepath to be removed, and appeared to have no effect at all.

[barnabycolby]

That last commit broke older versions of node, will investigate!

[barnabycolby]

The problem was that I used String.prototype.endsWith, which does not exist in older versions of node. In those cases, I fixed the problem by defining endsWith myself. @matthew-dean Over to you! :)

[matthew-dean]

Looks legit. 👍 I'll pull this into 3.x. Thanks!