fix: catch exceptions from SourceMapConsumer

lib/reporter.js

@@ -46,10 +46,15 @@ var createErrorFormatter = function(basePath, emitter, SourceMapConsumer) {
         column = parseInt(column || '0', 10);
 
         var smc = new SourceMapConsumer(file.sourceMap);
-        var original = smc.originalPositionFor({line: line, column: column});
+        try {
+          var original = smc.originalPositionFor({line: line, column: column});
 
-        return util.format('%s:%d:%d <- %s:%d:%d', path, line, column, original.source,
+          return util.format('%s:%d:%d <- %s:%d:%d', path, line, column, original.source,
             original.line, original.column);
+        } catch (e) {
+          log.warn('SourceMap position not found for trace: %s', msg);
+          // Fall back to non-source-mapped formatting.
+        }
       }
 
       return path + (line ? ':' + line : '') + (column ? ':' + column : '');

test/unit/reporter.spec.coffee

@@ -78,6 +78,9 @@ describe 'reporter', ->
         constructor: (sourceMap) ->
           @source = sourceMap.replace 'SOURCE MAP ', '/original/'
         originalPositionFor: (position) ->
+          if position.line == 0
+            throw new TypeError('Line must be greater than or equal to 1, got 0')
+
           source: @source
           line: position.line + 2
           column: position.column + 2
@@ -95,6 +98,19 @@ describe 'reporter', ->
           expect(formatError ERROR).to.equal 'at /some/base/b.js:2:6 <- /original/b.js:4:8\n'
           done()
 
+      it 'should fall back to non-source-map format if originalPositionFor throws', (done) ->
+        formatError = m.createErrorFormatter '/some/base', emitter, MockSourceMapConsumer
+        servedFiles = [new File('/some/base/a.js'), new File('/some/base/b.js')]
+        servedFiles[0].sourceMap = 'SOURCE MAP a.js'
+        servedFiles[1].sourceMap = 'SOURCE MAP b.js'
+
+        emitter.emit 'file_list_modified', q(served: servedFiles)
+
+        scheduleNextTick ->
+          ERROR = 'at https://localhost:123/base/b.js:0:0'
+          expect(formatError ERROR).to.equal 'at /some/base/b.js\n'
+          done()
+
       describe 'Windows', ->
         formatError = null
         servedFiles = null