Fix crash when replacing 0 length ranges, fixes #41

Author: goto-bus-stop

index.js

@@ -66,7 +66,11 @@ module.exports = function parse (modules, opts) {
                 s.stream.pipe(concat({ encoding: 'string' }, function (chunk) {
                     // We have to give magic-string the replacement string,
                     // so it can calculate the amount of lines and columns.
-                    sourcemapper.overwrite(s.start, s.start + s.offset, chunk);
+                    if (s.offset === 0) {
+                        sourcemapper.appendRight(s.start, chunk);
+                    } else {
+                        sourcemapper.overwrite(s.start, s.start + s.offset, chunk);
+                    }
                 })).on('finish', next);
             } else {
                 s.stream.on('end', next);

test/vars.js

@@ -77,7 +77,10 @@ test('multi consecutive require vars', function (t) {
                 return fs.createReadStream(file).pipe(quote());
             }
         }
-    }, { vars: { __dirname: path.join(__dirname, 'vars') } });
+    }, {
+        vars: { __dirname: path.join(__dirname, 'vars') },
+        sourceMap: true // Make sure source maps work when replacing 0 length ranges.
+    });
 
     readStream('multi-require.js').pipe(sm).pipe(concat(function (body) {
         Function(['console','require'],body)({ log: log }, function() { return {} });