Merge branch 'source-map-gen-apply-map'

lib/source-map/source-map-generator.js

@@ -146,6 +146,77 @@ define(function (require, exports, module) {
       }
     };
 
+  /**
+   * Applies a SourceMap for a source file to the SourceMap.
+   * Each mapping to the supplied source file is rewritten using the
+   * supplied SourceMap. Note: The resolution for the resulting mappings
+   * is the minimium of this map and the supplied map.
+   */
+  SourceMapGenerator.prototype.applySourceMap =
+    function SourceMapGenerator_applySourceMap(aSourceFile, aSourceMapConsumer) {
+      // aSourceFile is an optional argument
+      if(!aSourceMapConsumer) {
+        aSourceMapConsumer = aSourceFile;
+        aSourceFile = aSourceMapConsumer.file;
+      }
+      var sourceRoot = this._sourceRoot;
+      // Applying the SourceMap can add and remove items from the sources and
+      // the names array.
+      var newSources = new ArraySet();
+      var newNames = new ArraySet();
+
+      // Find mappings for the "aSourceFile"
+      this._mappings.forEach(function (mapping) {
+        if(mapping.source === aSourceFile && mapping.original) {
+          // Check if it can be mapped by the SourceMap.
+          // Than update the mapping.
+          var original = aSourceMapConsumer.originalPositionFor({
+            line: mapping.original.line,
+            column: mapping.original.column
+          });
+          if(original && original.source !== null) {
+            // Copy mapping
+            mapping.source = original.source;
+            mapping.original.line = original.line;
+            mapping.original.column = original.column;
+            mapping.name = mapping.name && original.name || mapping.name;
+            // Try to make source file relative to our sourceRoot
+            if(sourceRoot) {
+              var relativeUrl = util.relative(sourceRoot, mapping.source);
+              if(relativeUrl) {
+                mapping.source = relativeUrl;
+              }
+            }
+          }
+        }
+
+        var source = mapping.source;
+        if (source && !newSources.has(source)) {
+          newSources.add(source);
+        }
+
+        var name = mapping.name;
+        if (name && !newNames.has(name)) {
+          newNames.add(name);
+        }
+
+      }, this);
+      this._sources = newSources;
+      this._names = newNames;
+      aSourceMapConsumer.sources.forEach(function (sourceFile) {
+        var content = aSourceMapConsumer.sourceContentFor(sourceFile);
+        if(content) {
+          if(sourceRoot) {
+            var relativeUrl = util.relative(sourceRoot, sourceFile);
+            if(relativeUrl) {
+              sourceFile = relativeUrl;
+            }
+          }
+          generator.setSourceContent(sourceFile, content);
+        }
+      });
+    };
+
   /**
    * A mapping can have one of the three levels of data:
    *