Optionally allow replacement of existing mappings in SourceMap#addMapping().

lib/coffee-script/coffee-script.js

@@ -61,7 +61,9 @@
         fragment = fragments[_j];
         if (options.sourceMap) {
           if (fragment.locationData) {
-            options.sourceMap.addMapping([fragment.locationData.first_line, fragment.locationData.first_column], [currentLine, currentColumn]);
+            options.sourceMap.addMapping([fragment.locationData.first_line, fragment.locationData.first_column], [currentLine, currentColumn], {
+              noReplace: true
+            });
           }
           newLines = count(fragment.code, "\n");
           currentLine += newLines;

lib/coffee-script/sourcemap.js

@@ -10,10 +10,13 @@
       this.columnMappings = [];
     }
 
-    LineMapping.prototype.addMapping = function(generatedColumn, _arg) {
+    LineMapping.prototype.addMapping = function(generatedColumn, _arg, options) {
       var sourceColumn, sourceLine;
       sourceLine = _arg[0], sourceColumn = _arg[1];
-      if (this.columnMap[generatedColumn]) {
+      if (options == null) {
+        options = {};
+      }
+      if (this.columnMap[generatedColumn] && options.noReplace) {
         return;
       }
       this.columnMap[generatedColumn] = {
@@ -56,14 +59,17 @@
       this.generatedLines = [];
     }
 
-    SourceMap.prototype.addMapping = function(sourceLocation, generatedLocation) {
+    SourceMap.prototype.addMapping = function(sourceLocation, generatedLocation, options) {
       var generatedColumn, generatedLine, lineMapping;
+      if (options == null) {
+        options = {};
+      }
       generatedLine = generatedLocation[0], generatedColumn = generatedLocation[1];
       lineMapping = this.generatedLines[generatedLine];
       if (!lineMapping) {
         lineMapping = this.generatedLines[generatedLine] = new LineMapping(generatedLine);
       }
-      return lineMapping.addMapping(generatedColumn, sourceLocation);
+      return lineMapping.addMapping(generatedColumn, sourceLocation, options);
     };
 
     SourceMap.prototype.getSourcePosition = function(_arg) {

src/coffee-script.coffee

@@ -53,7 +53,8 @@ exports.compile = compile = (code, options = {}) ->
         if fragment.locationData
           options.sourceMap.addMapping(
             [fragment.locationData.first_line, fragment.locationData.first_column],
-            [currentLine, currentColumn])
+            [currentLine, currentColumn],
+            {noReplace: true})
         newLines = count fragment.code, "\n"
         currentLine += newLines
         currentColumn = fragment.code.length - (if newLines then fragment.code.lastIndexOf "\n" else 0)

src/sourcemap.coffee

@@ -10,8 +10,8 @@ class LineMapping
     # columnMappings is an array of all column mappings, sorted by generated-column.
     @columnMappings = []
 
-  addMapping: (generatedColumn, [sourceLine, sourceColumn]) ->
-    if @columnMap[generatedColumn]
+  addMapping: (generatedColumn, [sourceLine, sourceColumn], options={}) ->
+    if @columnMap[generatedColumn] and options.noReplace
       # We already have a mapping for this column.
       return
 
@@ -52,16 +52,17 @@ class exports.SourceMap
   # Adds a mapping to this SourceMap.
   #
   # `sourceLocation` and `generatedLocation` are both [line, column] arrays.
-  # If there is already a mapping for the specified `generatedLine` and
-  # `generatedColumn`, then this will have no effect.
-  addMapping: (sourceLocation, generatedLocation) ->
+  #
+  # If `options.noReplace` is true, then if there is already a mapping for
+  # the specified `generatedLine` and `generatedColumn`, this will have no effect.
+  addMapping: (sourceLocation, generatedLocation, options={}) ->
     [generatedLine, generatedColumn] = generatedLocation
 
     lineMapping = @generatedLines[generatedLine]
     if not lineMapping
       lineMapping = @generatedLines[generatedLine] = new LineMapping(generatedLine)
 
-    lineMapping.addMapping generatedColumn, sourceLocation
+    lineMapping.addMapping generatedColumn, sourceLocation, options
 
   # Returns [sourceLine, sourceColumn], or null if no mapping could be found.
   getSourcePosition: ([generatedLine, generatedColumn]) ->