fix(mergeMap): allow conccurent to be set as the second argument for …

[david-driscoll]

Description:
Allow concurrent to be supplied as the second argument for mergeMap and mergeMapTo.

Related issue (if exists):
see #1448 for discussion

Perf Details

On my machine the numbers were kind of hit or miss, so it's worth a second look by someone else as well. But the numbers look to not really be affected all that much.

---------------------------------------------------------------------------------------------------------------------------------------------------
-- BEFORE
---------------------------------------------------------------------------------------------------------------------------------------------------
                                         |                     RxJS 4.0.7 |              RxJS 5.0.0-beta.2 |          factor |      % improved
---------------------------------------------------------------------------------------------------------------------------------------------------
                    mergemap - immediate |                 1,871 (±4.96%) |                24,602 (±5.36%) |          13.15x |        1,215.2%
                                mergemap |                   575 (±4.30%) |                 3,779 (±5.71%) |           6.57x |          556.9%
---------------------------------------------------------------------------------------------------------------------------------------------------
                    mergemap - immediate |                 1,675 (±5.89%) |                20,097 (±5.73%) |          12.00x |        1,100.2%
                                mergemap |                   617 (±5.99%) |                 4,508 (±5.15%) |           7.30x |          630.5%
---------------------------------------------------------------------------------------------------------------------------------------------------
                    mergemap - immediate |                 2,300 (±3.36%) |                28,980 (±3.07%) |          12.60x |        1,159.8%
                                mergemap |                   761 (±3.28%) |                 5,644 (±3.56%) |           7.42x |          641.6%
---------------------------------------------------------------------------------------------------------------------------------------------------
-- AFTER
---------------------------------------------------------------------------------------------------------------------------------------------------
                                         |                     RxJS 4.0.7 |              RxJS 5.0.0-beta.2 |          factor |      % improved
---------------------------------------------------------------------------------------------------------------------------------------------------
                    mergemap - immediate |                 2,156 (±6.06%) |                27,358 (±5.14%) |          12.69x |        1,168.8%
                                mergemap |                   678 (±5.41%) |                 5,260 (±5.54%) |           7.75x |          675.3%
---------------------------------------------------------------------------------------------------------------------------------------------------
                    mergemap - immediate |                 1,781 (±6.55%) |                22,664 (±6.63%) |          12.72x |        1,172.4%
                                mergemap |                   589 (±4.92%) |                 4,865 (±5.04%) |           8.26x |          725.7%
---------------------------------------------------------------------------------------------------------------------------------------------------
                    mergemap - immediate |                 1,998 (±5.14%) |                26,582 (±4.79%) |          13.31x |        1,230.6%
                                mergemap |                   583 (±5.49%) |                 6,060 (±2.12%) |          10.39x |          939.2%
---------------------------------------------------------------------------------------------------------------------------------------------------

[kwonoj]

what about add type definition test in this PR as well?

[david-driscoll]

Hadn't thought about it, added!

[kwonoj]

👍

[kwonoj]

Just tried new 'reaction' feature to your PR :)

[kwonoj]

I'll check this in around today to tomorrow if there isn't additional suggestion.

[mattpodwysocki]

@david-driscoll @kwonoj wait, I think this should be thought through a bit since we want to have the following:

mergeMap(source, selector, resultSelector?)
mergeMap(source, selector)

Perhaps we should break it out into its own thing such as:

mergeMapConcurrent(source, maxConcurrent, selector, resultSelector?)

[trxcllnt]

@mattpodwysocki what are you saying is the source argument? we've already distinguished between mergeMap and mergeMapTo

[kwonoj]

I'll put on hold check in to clarify. Just in case, current mergeMap signature supports these.

mergeMap(project);
mergeMap(project, concurrent);
mergeMap(project, resultSelector);
mergeMap(project, resultSelector, concurrent);

[benlesh]

The commit message has a typo. conccurent => concurrent

[david-driscoll]

@Blesh fixed 😄

[benlesh]

Add a test for mergeMap(selecter, resultSelector, 2) so make sure it covers that call type.

Also, go through the tests and make sure every permutation of mergeMap has been called at least once. fn, fn, fn, fn, number, and fn, fn, number

[david-driscoll]

The result selector version is handled already above this test. As well as the single method test is handled above as well. Two methods, without concurrency isn't in there just yet, but that can be added fairly easily.

[benlesh]

LGTM.

[kwonoj]

Merged with c003468, thanks @david-driscoll !

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.