Add ignoreInvalidMapping option

CHANGELOG.md

@@ -1,5 +1,20 @@
 # Change Log
 
+## 1.1.0
+
+Add `ignoreInvalidMapping` option to `SourceMapGenerator`. If enabled, source-map-js will not throw an error on the incorrect previous source map. Instead, it will print warnings and ignore broken mappings.
+
+```js
+var generator = new sourceMap.SourceMapGenerator({
+  file: "my-generated-javascript-file.js",
+  sourceRoot: "http://example.com/app/js/",
+  ignoreInvalidMapping: true,
+});
+```
+
+* Do not throw an error since broken prev map is popular issue #20 ([#20](/~https://github.com/7rulnik/source-map-js/pull/20)) [@ai](/~https://github.com/ai)
+* Add ignoreInvalidMapping option ([#21](/~https://github.com/7rulnik/source-map-js/pull/21)) [@7rulnik](/~https://github.com/7rulnik)
+
 ## 1.0.3
 
 * Use sourceContents when non-null, even if it's an empty string ([#17](/~https://github.com/7rulnik/source-map-js/pull/17)) [@bshepherdson](/~https://github.com/bshepherdson)

README.md

@@ -466,6 +466,9 @@ You may pass an object with the following properties:
   discretion, as a last resort. Even then, one should avoid using this flag when
   running tests, if possible.
 
+* `ignoreInvalidMapping`: Optional. When `true`, instead of throwing error on
+  invalid mapping, it will be ignored.
+
 ```js
 var generator = new sourceMap.SourceMapGenerator({
   file: "my-generated-javascript-file.js",

lib/source-map-generator.js

@@ -25,6 +25,7 @@ function SourceMapGenerator(aArgs) {
   this._file = util.getArg(aArgs, 'file', null);
   this._sourceRoot = util.getArg(aArgs, 'sourceRoot', null);
   this._skipValidation = util.getArg(aArgs, 'skipValidation', false);
+  this._ignoreInvalidMapping = util.getArg(aArgs, 'ignoreInvalidMapping', false);
   this._sources = new ArraySet();
   this._names = new ArraySet();
   this._mappings = new MappingList();
@@ -275,14 +276,18 @@ SourceMapGenerator.prototype._validateMapping =
     // 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') {
-      if (typeof console !== 'undefined' && console.warn) {
-        console.warn(
-            '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.'
-        );
+      var message = '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 (this._ignoreInvalidMapping) {
+        if (typeof console !== 'undefined' && console.warn) {
+          console.warn(message);
+        }
+        return false;
+      } else {
+        throw new Error(message);
       }
-      return false;
     }
 
     if (aGenerated && 'line' in aGenerated && 'column' in aGenerated
@@ -300,15 +305,21 @@ SourceMapGenerator.prototype._validateMapping =
       return;
     }
     else {
-      if (typeof console !== 'undefined' && console.warn) {
-        console.warn('Invalid mapping: ' + JSON.stringify({
-          generated: aGenerated,
-          source: aSource,
-          original: aOriginal,
-          name: aName
-        }));
+      var message = 'Invalid mapping: ' + JSON.stringify({
+        generated: aGenerated,
+        source: aSource,
+        original: aOriginal,
+        name: aName
+      });
+
+      if (this._ignoreInvalidMapping) {
+        if (typeof console !== 'undefined' && console.warn) {
+          console.warn(message);
+        }
+        return false;
+      } else {
+        throw new Error(message)
       }
-      return false;
     }
   };