Fix stack trace of errors propagated by expect.withError

[papandreou]

I don't understand exactly how this fixes the problem, but it changes the stack from:

UnexpectedError: 
expected 2 to equal 'wat'
    at callInNestedContext (/home/andreas/work/unexpected/lib/Unexpected.js:653:44)
    at Function.wrappedExpect.fail (/home/andreas/work/unexpected/lib/Unexpected.js:690:17)
    at /home/andreas/work/unexpected/lib/assertions.js:425:20
    at /home/andreas/work/unexpected/lib/Unexpected.js:698:28
    at tryCatcher (/home/andreas/work/unexpected/node_modules/bluebird/js/main/util.js:24:31)
    at Promise._settlePromiseFromHandler (/home/andreas/work/unexpected/node_modules/bluebird/js/main/promise.js:454:31)
    at Promise._settlePromiseAt (/home/andreas/work/unexpected/node_modules/bluebird/js/main/promise.js:530:18)
    at Promise._settlePromiseAtPostResolution (/home/andreas/work/unexpected/node_modules/bluebird/js/main/promise.js:224:10)
    at Async._drainQueue (/home/andreas/work/unexpected/node_modules/bluebird/js/main/async.js:182:12)
    at Async._drainQueues (/home/andreas/work/unexpected/node_modules/bluebird/js/main/async.js:187:10)
    at Async.drainQueues (/home/andreas/work/unexpected/node_modules/bluebird/js/main/async.js:15:14)
    at /home/andreas/work/unexpected/lib/workQueue.js:8:13
    at Array.forEach (native)
    at Object.workQueue.drain (/home/andreas/work/unexpected/lib/workQueue.js:7:20)
    at oathbreaker (/home/andreas/work/unexpected/lib/oathbreaker.js:43:15)
    at Function.wrappedExpect.withError (/home/andreas/work/unexpected/lib/Unexpected.js:696:24)

to

UnexpectedError: 
expected 2 to equal 'wat'
    at callInNestedContext (/home/andreas/work/unexpected/lib/Unexpected.js:653:44)
    at Function.wrappedExpect.fail (/home/andreas/work/unexpected/lib/Unexpected.js:690:17)
    at /home/andreas/work/unexpected/lib/assertions.js:425:20
    at Function.wrappedExpect.withError (/home/andreas/work/unexpected/lib/Unexpected.js:702:28)
    at Assertion.<anonymous> (/home/andreas/work/unexpected/lib/assertions.js:422:16)
    at executeExpect (/home/andreas/work/unexpected/lib/Unexpected.js:720:34)
    at Unexpected.expect (/home/andreas/work/unexpected/lib/Unexpected.js:798:22)
    at Object.<anonymous> (/home/andreas/work/unexpected/argh.js:3:1)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:906:3

when I run my test script, argh.js with this content from the root of my unexpected checkout:

var expect = require('./lib/');

expect(2, 'to equal', 'wat');

It's seems very likely that it's just masking a bug in oathbreaker or makePromise, though :/

[sunesimonsen]

I think this masking a bug, see the following evaluation:

> require('./lib/makePromise')(function () { throw new Error('wat')}).caught(function (err) { throw err; }).isRejected()
false
> 
/home/ubuntu-sune/Projects/unexpected/lib/workQueue.js:29
                throw that.reason();
                           ^
Error: wat
    at repl:1:34
    at /home/ubuntu-sune/Projects/unexpected/lib/makePromise.js:59:38
    at tryCatcher (/home/ubuntu-sune/Projects/unexpected/node_modules/bluebird/js/main/util.js:24:31)
    at Promise._resolveFromResolver (/home/ubuntu-sune/Projects/unexpected/node_modules/bluebird/js/main/promise.js:427:31)
    at new Promise (/home/ubuntu-sune/Projects/unexpected/node_modules/bluebird/js/main/promise.js:53:37)
    at makePromise (/home/ubuntu-sune/Projects/unexpected/lib/makePromise.js:16:12)
    at repl:1:2
    at REPLServer.self.eval (repl.js:110:21)
    at Interface.<anonymous> (repl.js:239:12)
    at Interface.EventEmitter.emit (events.js:95:17)
    at Interface._onLine (readline.js:202:10)
    at Interface._line (readline.js:531:8)
    at Interface._ttyWrite (readline.js:760:14)
    at ReadStream.onkeypress (readline.js:99:10)
    at ReadStream.EventEmitter.emit (events.js:98:17)
    at emitKey (readline.js:1095:12)

[papandreou]

I also played with it a bit more this morning, looking through makePromise.js, but I didn't get any closer to the root cause.

[sunesimonsen]

I'll see if I can get some time to look at it today, otherwise we should just merge the pr.

[sunesimonsen]

This actually works:

> require('./lib/oathbreaker')(require('./lib/makePromise')(function () { throw new Error('wat') }).caught(function (err) { throw err; }))
Error: wat
    at repl:1:80
    at /home/ubuntu-sune/Projects/unexpected/lib/makePromise.js:59:38
    at tryCatcher (/home/ubuntu-sune/Projects/unexpected/node_modules/bluebird/js/main/util.js:24:31)
    at Promise._resolveFromResolver (/home/ubuntu-sune/Projects/unexpected/node_modules/bluebird/js/main/promise.js:427:31)
    at new Promise (/home/ubuntu-sune/Projects/unexpected/node_modules/bluebird/js/main/promise.js:53:37)
    at makePromise (/home/ubuntu-sune/Projects/unexpected/lib/makePromise.js:16:12)
    at repl:1:59
    at REPLServer.self.eval (repl.js:110:21)
    at Interface.<anonymous> (repl.js:239:12)
    at Interface.EventEmitter.emit (events.js:95:17)
    at Interface._onLine (readline.js:202:10)
    at Interface._line (readline.js:531:8)
    at Interface._ttyWrite (readline.js:760:14)
    at ReadStream.onkeypress (readline.js:99:10)
    at ReadStream.EventEmitter.emit (events.js:98:17)
    at emitKey (readline.js:1095:12)

But this doesn't:

> require('./lib/oathbreaker')(require('./lib/makePromise')(function (run) { run(function () {throw new Error('wat')}) }).caught(function (err) { throw err; }))
{ _bitField: 0,
  _fulfillmentHandler0: undefined,
  _rejectionHandler0: undefined,
  _progressHandler0: undefined,
  _promise0: undefined,
  _receiver0: undefined,
  _settledValue: undefined }

[papandreou]

Superseeded by #197.