promise tests failing under recent versions of iojs

[othiym23]

Hey @Qard, I'd like to make this your problem if I could, since you wrote the original code. Under at least [email protected] and [email protected], the promise tests show a bunch of failures where they're getting deeper trace trees than they were expecting. Also, something's causing things to go bozotic with EEs in the test:

(node) warning: possible EventEmitter memory leak detected. 11 close listeners added. Use emitter.setMaxListeners() to increase limit.
Trace
    at Stream.addListener (events.js:236:17)
    at Stream.pipe (stream.js:52:12)
    at module.exports (/Users/ogd/Documents/projects/async-listener/node_modules/tap/node_modules/difflet/node_modules/charm/index.js:42:15)
    at difflet (/Users/ogd/Documents/projects/async-listener/node_modules/tap/node_modules/difflet/index.js:41:17)
    at Function.fn.compare (/Users/ogd/Documents/projects/async-listener/node_modules/tap/node_modules/difflet/index.js:20:9)
    at diffObject (/Users/ogd/Documents/projects/async-listener/node_modules/tap/lib/tap-assert.js:419:50)
    at assert (/Users/ogd/Documents/projects/async-listener/node_modules/tap/lib/tap-assert.js:55:18)
    at Function.equivalent (/Users/ogd/Documents/projects/async-listener/node_modules/tap/lib/tap-assert.js:183:12)
    at Test._testAssert (/Users/ogd/Documents/projects/async-listener/node_modules/tap/lib/tap-test.js:87:16)
    at next (/Users/ogd/Documents/projects/async-listener/test/native-promises.tap.js:497:9)
(node) warning: possible EventEmitter memory leak detected. 11 end listeners added. Use emitter.setMaxListeners() to increase limit.
Trace
    at Stream.addListener (events.js:236:17)
    at Stream.pipe (stream.js:99:10)
    at module.exports (/Users/ogd/Documents/projects/async-listener/node_modules/tap/node_modules/difflet/node_modules/charm/index.js:42:15)
    at difflet (/Users/ogd/Documents/projects/async-listener/node_modules/tap/node_modules/difflet/index.js:41:17)
    at Function.fn.compare (/Users/ogd/Documents/projects/async-listener/node_modules/tap/node_modules/difflet/index.js:20:9)
    at diffObject (/Users/ogd/Documents/projects/async-listener/node_modules/tap/lib/tap-assert.js:419:50)
    at assert (/Users/ogd/Documents/projects/async-listener/node_modules/tap/lib/tap-assert.js:55:18)
    at Function.equivalent (/Users/ogd/Documents/projects/async-listener/node_modules/tap/lib/tap-assert.js:183:12)
    at Test._testAssert (/Users/ogd/Documents/projects/async-listener/node_modules/tap/lib/tap-test.js:87:16)
    at next (/Users/ogd/Documents/projects/async-listener/test/native-promises.tap.js:497:9)
not ok test/native-promises.tap.js .................... 24/29

Perhaps this is related to the changes that Trevor or vkurchatkin (I think?) landed around the microtask queue in [email protected]? Either way, let me know within a day or two if you're going to tackle these, or if I should budget some time to get my head around this code and fix it myself.

[Qard]

I'll have a bit of time to look at it tomorrow. I'm not sure what I'll discover. @hayes may also have some ideas, since he expanded a bunch on my initial effort.

[hayes]

I don't really have time at the moment to dig into this. Looks like some new things are happening under the hood that were not happening in pre 1.3 versions of iojs

[Qard]

The EventEmitter leak seems to not be a problem with async-listener at all, it seems to originate from tap. Specifically, this line: https://github.com/isaacs/node-tap/blob/master/lib/tap-assert.js#L55

It surfaces when tap tries to use difflet to display a highlighted object diff. I bypassed that by just commenting out that line and doing process._rawDebug(...) calls on json stringified res.found and res.wanted.

The real error is a structural difference in the deep equality check that is produced by the addListner() helper versus what actually gets produced by the manually built object:

// found
found {
  "name": "root",
  "children": [{
    "name": "reject",
    "children": [{
      "name": "nextTick in catch",
      "children": [],
      "before": 1,
      "after": 1,
      "error": 0
    }, {
      "name": "setTimeout in then",
      "children": [],
      "before": 1,
      "after": 0,
      "error": 0
    }],
    "before": 2,
    "after": 2,
    "error": 0
  }, {
    "name": "reject",
    "children": [],
    "before": 1,
    "after": 1,
    "error": 0
  }, {
    "name": "setImmediate in root",
    "children": [],
    "before": 1,
    "after": 1,
    "error": 0
  }],
  "before": 0,
  "after": 0,
  "error": 0
}

// wanted
{
  "name": "root",
  "children": [{
    "name": "reject",
    "children": [{
      "name": "nextTick in catch",
      "children": [],
      "before": 1,
      "after": 1,
      "error": 0
    }, {
      "name": "setTimeout in then",
      "children": [],
      "before": 1,
      "after": 0,
      "error": 0
    }],
    "before": 2,
    "after": 2,
    "error": 0
  }, {
    "name": "setImmediate in root",
    "children": [],
    "before": 1,
    "after": 1,
    "error": 0
  }],
  "before": 0,
  "after": 0,
  "error": 0
}

Note the extra reject in what was found. I'm not yet sure why it does this, just that it is doing it.