undefined error solved

[abdulrehmank]

remainingLines[remainingLinesIndex] sometimes give undefined and the build gets failed

[tromey]

Thanks for the patch. This bug has been reported a few times, and there's another PR open for it (since obsoleted by other changes) -- but what is missing is a test case. I'd like to have one before merging this. I'm willing to write the test myself but I don't know how to reproduce the bug. Could you either write a test or explain how I can do so?

[fictitious]

From my limited understanding, it happens when source code passed to fromStringWithSourceMap does not correspond to the sourcemap in SourceMapConsumer.

If you start by adding this test to test-source-node.js (which passes)

exports['test .fromStringWithSourceMap() empty code'] = function (assert) {
  var emptyCode = '';
  var node = SourceNode.fromStringWithSourceMap(
      emptyCode,
      new SourceMapConsumer(util.emptyMap));

  var result = node.toStringWithSourceMap({
    file: 'min.js'
  });
  var map = result.map;
  var code = result.code;

  assert.equal(code, emptyCode);
  assert.ok(map instanceof SourceMapGenerator, 'map instanceof SourceMapGenerator');
  map = map.toJSON();
  assert.equal(map.version, util.emptyMap.version);
  assert.equal(map.file, util.emptyMap.file);
  assert.equal(map.mappings, util.emptyMap.mappings);
};

then change it and make consumer to use testMap:

  var node = SourceNode.fromStringWithSourceMap(
      emptyCode,
      new SourceMapConsumer(util.testMap));

you get

FAILED ./test-source-node: test .fromStringWithSourceMap() empty code!
TypeError: Cannot read property 'substr' of undefined
    at Function.<anonymous> (...source-map/lib/source-node.js:121:26)

This is unlikely a valid use case, it probably just exposes some other bug somewhere in the code that uses sourcemap, and that code should be fixed regardless of what is done here.

[tromey]

Obsoleting in favor of #288 - same thing, slightly different spelling.