Add tests for applying source maps and refactor

Author: conradz

lib/source-map-support.js

@@ -101,7 +101,8 @@ exports.emit = function(str, pos, startOnly) {
 
 exports.addFile = function(pos) {
   var file = pos.source || 'source.css';
-  if (this.files.hasOwnProperty(file)) return;
+  if (Object.prototype.hasOwnProperty.call(this.files, file)) return;
+  if (typeof pos.content !== 'string') return;
   this.files[file] = pos.content;
 };
 
@@ -110,14 +111,14 @@ exports.addFile = function(pos) {
  */
 
 exports.applySourceMaps = function() {
-  for (var file in this.files) {
+  Object.keys(this.files).forEach(function(file) {
     var originalMap = sourceMapResolve.resolveSync(
       this.files[file], file, fs.readFileSync);
     if (originalMap) {
       originalMap = new SourceMapConsumer(originalMap.map);
       this.map.applySourceMap(originalMap, file);
     }
-  }
+  }, this);
 };
 
 /**

test/cases/source-map-apply.scss

@@ -69,4 +69,28 @@ describe('stringify(obj, {sourcemap: true})', function(){
     map.originalPositionFor({ line: 1, column: 64 }).should.eql(locs.mediaOnly);
     map.sourceContentFor('rules.css').should.eql(src);
   });
+
+  it('should apply included source maps', function(){
+    var file = 'test/source-map-apply.css';
+    var src = read(file, 'utf8');
+    var stylesheet = parse(src, { source: file, position: true });
+    var result = stringify(stylesheet, { sourcemap: true });
+    result.should.have.property('code');
+    result.should.have.property('map');
+
+    var map = new SourceMapConsumer(result.map);
+    map.originalPositionFor({ line: 1, column: 0 }).should.eql({
+      column: 0,
+      line: 1,
+      name: null,
+      source: 'source-map-apply.scss'
+    });
+
+    map.originalPositionFor({ line: 2, column: 2 }).should.eql({
+      column: 7,
+      line: 1,
+      name: null,
+      source: 'source-map-apply.scss'
+    });
+  });
 });

test/css-stringify.js

@@ -0,0 +1 @@
+tobi { name: 'tobi'; }