support pass string to node-sass sourceMap option (#269)

* support pass string to node-sass sourceMap option
* add test case: set sass sourcemap option to string
* update scss adapter doc

docs/scss.md

@@ -6,7 +6,12 @@ This adapter uses [node-sass](https://github.com/andrew/node-sass), an incredibl
 
 ## Source Maps
 
-Libsass does not yet support source maps, although at the time of writing there is [an open pull request](https://github.com/sass/libsass/pull/591) to work on this.
+`node-sass` (include its dependency `libsass`) currently supports sourcemap. And you can use `sourcemap` option to enable this feature.
+
+1. When passing `Boolean` value to `sourcemap`, it means enable/disable the sourcemap. And the `sources` property of generated sourcemap is array of absolute paths.
+2. When passing `String` value to `sourcemap`, the `sources` property of generated sourcemap is array of relative paths (relative to the scss file).
+
+See [node-sass Options.sourceMap](https://github.com/sass/node-sass#sourcemap) for more details.
 
 ## Additional Options
 It has a pretty standard API, and uses the [options documented here](https://github.com/andrew/node-sass#options). Do not pass through `data` or `file`, as this will be overridden by accord's wrapper - everything else is fair game.

lib/adapters/scss/2.x.coffee

@@ -11,8 +11,11 @@ class SCSS extends Adapter
   _render: (str, options) ->
     deferred = W.defer()
 
-    if options.sourcemap is true
-      options.sourceMap = true
+    if options.sourcemap
+      if typeof options.sourcemap is 'string'
+        options.sourceMap = options.sourcemap
+      else
+        options.sourceMap = true
       options.outFile = path.basename(options.filename).replace('.scss', '.css')
       options.omitSourceMapUrl = true
       options.sourceMapContents = true

lib/adapters/scss/3.x - 4.x.coffee

@@ -11,8 +11,11 @@ class SCSS extends Adapter
   _render: (str, options) ->
     deferred = W.defer()
 
-    if options.sourcemap is true
-      options.sourceMap = true
+    if options.sourcemap
+      if typeof options.sourcemap is 'string'
+        options.sourceMap = options.sourcemap
+      else
+        options.sourceMap = true
       options.outFile = options.filename.replace('.scss', '.css')
       options.omitSourceMapUrl = true
       options.sourceMapContents = true
@@ -35,9 +38,10 @@ class SCSS extends Adapter
       if res.map
         data.sourcemap = JSON.parse(res.map.toString('utf8'))
         basePath = path.dirname(options.filename)
-        data.sourcemap.sources =
-          data.sourcemap.sources.map (relativePath) ->
-            path.join(basePath, relativePath)
+        if typeof options.sourceMap isnt 'string'
+          data.sourcemap.sources =
+            data.sourcemap.sources.map (relativePath) ->
+              path.join(basePath, relativePath)
 
       deferred.resolve(data)
 

test/test.coffee

@@ -913,6 +913,19 @@ describe 'scss', ->
         res.sourcemap.sourcesContent.length.should.equal(2)
       .then((res) => should.match_expected(@scss, res.result, lpath))
 
+  it 'should generate a sourcemap with correct relative sources', ->
+    lpath = path.join(@path, 'external.scss')
+    mixinpath = path.join(@path, '_mixin_lib.scss')
+    @scss.renderFile(lpath, { sourcemap: lpath })
+      .tap (res) ->
+        res.sourcemap.version.should.equal(3)
+        res.sourcemap.mappings.length.should.be.above(1)
+        res.sourcemap.sources.length.should.equal(2)
+        res.sourcemap.sources[0].should.equal('external.scss')
+        res.sourcemap.sources[1].should.equal('_mixin_lib.scss')
+        res.sourcemap.sourcesContent.length.should.equal(2)
+      .then((res) => should.match_expected(@scss, res.result, lpath))
+
 describe 'less', ->
 
   before ->