Merge pull request #66 from novemberborn/improve-source-maps

Improve source maps

index.js

@@ -72,6 +72,7 @@ NYC.prototype.addFile = function (filename, returnImmediately) {
   var content = stripBom(fs.readFileSync(filename, 'utf8'))
 
   if (instrument) {
+    this.sourceMapCache.add(filename, content)
     content = this.instrumenter.instrumentSync(content, './' + relFile)
   } else if (returnImmediately) {
     return {}

lib/source-map-cache.js

@@ -11,7 +11,7 @@ function SourceMapCache (opts) {
 }
 
 SourceMapCache.prototype.add = function (filename, source) {
-  var sourceMap = convertSourceMap.fromSource(source)
+  var sourceMap = convertSourceMap.fromSource(source) || convertSourceMap.fromMapFileSource(source, path.dirname(filename))
   if (sourceMap) this.cache['./' + path.relative(this.cwd, filename)] = new SourceMapConsumer(sourceMap.sourcemap)
 }
 
@@ -20,16 +20,31 @@ SourceMapCache.prototype.applySourceMaps = function (coverage) {
   var mappedCoverage = _.cloneDeep(coverage)
 
   Object.keys(coverage).forEach(function (key) {
-    if (_this.cache[key]) {
-      _this._rewriteStatements(mappedCoverage[key], _this.cache[key])
-      _this._rewriteFunctions(mappedCoverage[key], _this.cache[key])
-      _this._rewriteBranches(mappedCoverage[key], _this.cache[key])
+    var sourceMap = _this.cache[key]
+    if (!sourceMap) {
+      return
     }
+
+    var fileCoverage = mappedCoverage[key]
+    _this._rewritePath(mappedCoverage, fileCoverage, sourceMap)
+    _this._rewriteStatements(fileCoverage, sourceMap)
+    _this._rewriteFunctions(fileCoverage, sourceMap)
+    _this._rewriteBranches(fileCoverage, sourceMap)
   })
 
   return mappedCoverage
 }
 
+SourceMapCache.prototype._rewritePath = function (mappedCoverage, coverage, sourceMap) {
+  // only rewrite the path if the file comes from a single source
+  if (sourceMap.sources.length !== 1) return
+
+  var originalPath = './' + path.join(path.dirname(coverage.path), sourceMap.sources[0])
+  delete mappedCoverage[coverage.path]
+  coverage.path = originalPath
+  mappedCoverage[originalPath] = coverage
+}
+
 SourceMapCache.prototype._rewriteStatements = function (coverage, sourceMap) {
   var start = null
   var end = null