test: fix flaky test-http-client-timeout-event

[Trott]

Checklist

• make -j4 test (UNIX), or vcbuild test nosign (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

test http

Description of change

Race condition caused occasional failure on CI. Chained callbacks used
to remove race condition.

[Trott]

Sample CI failure:

https://ci.nodejs.org/job/node-test-commit-freebsd/5892/nodes=freebsd10-64/console

not ok 464 parallel/test-http-client-timeout-event
  ---
  duration_ms: 1.240
  severity: fail
  stack: |-
    
    assert.js:85
      throw new assert.AssertionError({
      ^
    AssertionError: 0 === 1
        at Timeout._onTimeout (/usr/home/iojs/build/workspace/node-test-commit-freebsd/nodes/freebsd10-64/test/parallel/test-http-client-timeout-event.js:28:12)
        at ontimeout (timers.js:365:14)
        at tryOnTimeout (timers.js:237:5)
        at Timer.listOnTimeout (timers.js:207:5)

[Trott]

I am able to replicate that failure locally by running the test in parallel with itself:

tools/test.py -j 32 parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event parallel/test-http-client-timeout-event

Result:

=== release test-http-client-timeout-event ===                    
Path: parallel/test-http-client-timeout-event
assert.js:85
  throw new assert.AssertionError({
  ^
AssertionError: 0 === 1
    at Timeout._onTimeout (/Users/trott/io.js/test/parallel/test-http-client-timeout-event.js:28:12)
    at ontimeout (timers.js:365:14)
    at tryOnTimeout (timers.js:237:5)
    at Timer.listOnTimeout (timers.js:207:5)
Command: out/Release/node /Users/trott/io.js/test/parallel/test-http-client-timeout-event.js
=== release test-http-client-timeout-event ===                   
Path: parallel/test-http-client-timeout-event
assert.js:85
  throw new assert.AssertionError({
  ^
AssertionError: 0 === 1
    at Timeout._onTimeout (/Users/trott/io.js/test/parallel/test-http-client-timeout-event.js:28:12)
    at ontimeout (timers.js:365:14)
    at tryOnTimeout (timers.js:237:5)
    at Timer.listOnTimeout (timers.js:207:5)
Command: out/Release/node /Users/trott/io.js/test/parallel/test-http-client-timeout-event.js
[00:01|% 100|+  30|-   2]: Done  

Running the same command with the changes in this PR results in success.

[Trott]

CI: https://ci.nodejs.org/job/node-test-pull-request/5424/

[Trott]

@nodejs/testing

[Trott]

The widget keeps reporting arm as failing on various pull requests even when it's successful (like here). Not sure what's up with that, but I guess /cc @jbergstroem as an FYI.

[Trott]

CI stress test showing current master failing: https://ci.nodejs.org/job/node-stress-single-test/1074/nodes=freebsd10-64/console

CI stress test showing this branch passing: https://ci.nodejs.org/job/node-stress-single-test/1075/nodes=freebsd10-64/console

[Trott]

Landed in 348e69c