upgrade dependencies

1 files changed, 12 insertions, 0 deletions

diff --git a/node_modules/source-map/lib/source-map-generator.js b/node_modules/source-map/lib/source-map-generator.js
index 8fbb8e8b7..aff1e7fb2 100644
--- a/node_modules/source-map/lib/source-map-generator.js
+++ b/node_modules/source-map/lib/source-map-generator.js
@@ -259,6 +259,18 @@ SourceMapGenerator.prototype.applySourceMap =
 SourceMapGenerator.prototype._validateMapping =
   function SourceMapGenerator_validateMapping(aGenerated, aOriginal, aSource,
                                               aName) {
+    // When aOriginal is truthy but has empty values for .line and .column,
+    // it is most likely a programmer error. In this case we throw a very
+    // specific error message to try to guide them the right way.
+    // For example: https://github.com/Polymer/polymer-bundler/pull/519
+    if (aOriginal && typeof aOriginal.line !== 'number' && typeof aOriginal.column !== 'number') {
+        throw new Error(
+            'original.line and original.column are not numbers -- you probably meant to omit ' +
+            'the original mapping entirely and only map the generated position. If so, pass ' +
+            'null for the original mapping instead of an object with empty or null values.'
+        );
+    }
+
     if (aGenerated && 'line' in aGenerated && 'column' in aGenerated
         && aGenerated.line > 0 && aGenerated.column >= 0
         && !aOriginal && !aSource && !aName) {