Defective source maps

[durad]

Source maps that compiler produces have some defects. I've tried compiling a simple code snippet:

(function (_) {
    console.log(111);
    setTimeout(_, 10000);
    console.log(222);
})(function () {});

and it compiled to:

/*** Generated by streamline 0.10.15 (callbacks) - DO NOT EDIT ***/
var __rt=require('streamline/lib/callbacks/runtime').runtime(__filename, false),__func=__rt.__func,__cb=__rt.__cb;
(function __1(_) {
  var __frame = {
    name: "__1",
    line: 1
  };
  return __func(_, this, arguments, __1, 0, __frame, function __$__1() {
    console.log(111);
    return setTimeout(__cb(_, __frame, 2, 4, function __$__1() {
      console.log(222);
      _();
    }, true), 10000);
  });
})(function() {

});
//# sourceMappingURL=b.map 

with a sourcemap:

{"version":3,"sources":["b._js"],"names":[],"mappings":";;;;;;;;IACI,QAAQ,GAAR,CAAY,GAAZ,E;WACA,W;MACA,QAAQ,GAAR,CAAY,GAAZ,E;;YADU,EAAI,KAAd,C;;GAED,W","file":"b.js","sourceRoot":""}

The compiled code works as expected, however when I parsed the resulting b.map file using source-map module and looped through all of the mappings and printed original line/column and generated line/column here is what I got:

(2, 4) -> (9, 4)
(2, 12) -> (9, 12)
(2, 4) -> (9, 15)
(2, 16) -> (9, 16)
(2, 4) -> (9, 19)
(undefined, undefined) -> (9, 21)
(3, 4) -> (10, 11)
(undefined, undefined) -> (10, 22)
(4, 4) -> (11, 6)
(4, 12) -> (11, 14)
(4, 4) -> (11, 17)
(4, 16) -> (11, 18)
(4, 4) -> (11, 21)
(undefined, undefined) -> (11, 23)
(3, 14) -> (13, 12)
(3, 18) -> (13, 14)
(3, 4) -> (13, 19)
(undefined, undefined) -> (13, 20)
(5, 3) -> (15, 3)
(undefined, undefined) -> (15, 14)

The first problem is that some of the source line/columns are missing and source-map module is parsing them as undefined.

Second problem is that source line/column pairs are not unique, so in this example you can see that (2, 4) is mapping to (9, 4), (9, 15) and so on.

This is a big problem and makes debugging and the whole build pipeline very difficult. Is there anything that can be done about this?

[bjouhier]

Looks like a bug. I'll look at it but I won't have time this week.

[durad]

Any luck with this yet?

[bjouhier]

@77V I have put a fix but I won't be testing it extensively because we are not routinely using sourcemaps in our build chain. If you validate it I'll push a new version to npm.

[durad]

I've cloned the repository and then npm installed it from that folder. However when I try too run the compiler I get the following message:

root@ubuntuserver14:/home/dusan/sltest4# ./node_modules/.bin/_node -m -c s._js TypeError: Object #<MappingList> has no method 'filter' <<< async stack >>> at _compile (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/compile.js:404:19) at __1 (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/compile.js:420:3) at value__1 (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/builtins.js:131:32) at exports_compile__4 (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/compile.js:419:8) <<< raw stack >>> at fixSourceMap (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/compile.js:117:45) at ___ (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/compile.js:198:19) at ___ (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/runtime.js:109:13) at /home/dusan/sltest4/node_modules/streamline/lib/callbacks/runtime.js:97:14 at Object.__g.trampoline.flush (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/runtime.js:23:29) at ___ (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/runtime.js:120:61) at fs.js:271:14 at Object.oncomplete (fs.js:107:15) errors found in 1 files Error: errors found in 1 files at __$exports_compile__4 (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/compile.js:422:30) at ___ (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/runtime.js:109:13) at __$value__1 (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/builtins.js:134:129) at __$value__1 (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/builtins.js:131:235) at ___ (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/runtime.js:109:13) at __$value__1 (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/builtins.js:131:194) at ___ (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/runtime.js:109:13) at __$__1 (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/compile.js:422:301) at ___ (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/runtime.js:109:13) at __tryCatch (/home/dusan/sltest4/node_modules/streamline/lib/callbacks/runtime.js:148:4)

[bjouhier]

It looks like I fixed it with a different version of sourcemap. I'll investigate.

[bjouhier]

@77V should work now with latest sourcemap code.

[durad]

It's working now, I'm closing the issue.