Test `npm --version` in child process

Reason

Using the NativeScript CLI to build an Android app took around 6 minutes on a Windows system compared to around 1 minute on our old Mac.

Debugging showed that the process hangs for 3 minutes when trying to get the currently installed npm version in this script.

To get the npm version, NativeScript executes the command npm -v in a child process and waits for the output.

It seemed strange that this alone took 3 minutes to complete. I wrote this script to test in isolation. The callback function is called just before the close event occurs. Without a timeout this happens after 3 minutes. When setting a timeout, the close event is fired after the timeout period.

Example output

Expected output:

2018-6-13 13:15:32 - START
2018-6-13 13:15:33 - DATA - npm version: 5.6.0
2018-6-13 13:15:33 - EXIT - 0
childProcess.exec: 934.978ms
2018-6-13 13:15:37 - CLOSE - 0

Actual output without an expicit timeout:

2018-6-13 13:15:32 - START
2018-6-13 13:15:33 - DATA - npm version: 5.6.0
2018-6-13 13:15:33 - EXIT - 0
childProcess.exec: 189416.095ms
2018-6-13 13:18:31 - CLOSE - 0

Actual output with an timeout of 10 seconds:

2018-6-13 10:32:34 - START
2018-6-13 10:32:35 - DATA - npm version: 5.6.0
2018-6-13 10:32:35 - EXIT - 0
childProcess.exec: 10019.768ms
2018-6-13 10:32:43 - CLOSE - 0

It seemed that something was preventing the child process from closing. I added the wtfnode module to see open handles. Testing different node/npm combinations revealed that this "error" started to occur with npm version 4.4.0 (the node version did not make a difference).

Test Matrix

npm	Node 4.9.1	Node 6.11.2	Node 7.10.1	Node 8.11.3	Node 9.11.2	Node 4.9.1
2.15.12	ok	ok	ok	ok	ok	ok
3.10.10	ok	ok	ok	ok	ok	ok
4.2.0	ok	ok	ok	ok	ok	ok
4.3.0	ok	ok	ok	ok	ok	ok
4.4.0	-	-	-	-	-	-
4.6.1	-	-	-	-	-	-
5.6.0	-	-	-	-	-	-
5.10.0	-	-	-	-	-	-
6.1.0	-	-	-	-	-	-

Cause

npm 4.4.0 introduced an update notification feature. When behind a corporate proxy (like we are) the update check can't be completed and times out after 3 minutes. Only then the child process is closed and the script execution goes on.

The update check feature uses the update-notifier package that uses the latest-version package which in turn uses package-json. package-json currently does not support proxies and the author seems not to be willing to implement proxy support.

Workarounds

See https://github.com/yeoman/update-notifier#user-settings

Set environment variable NO_UPDATE_NOTIFIER=1
Use --no-update-notifier flag
Set "optOut": true in ~/.config/configstore/update-notifier-[your-module-name].json

Possible Solutions

Skip update check if a proxy is used (check if proxy variables are set in npm config?)
Implement a (short) timeout for the proxy check and kill the child process after that (would have to be implemented in update-notifier package
Use another module for the update check that has proxy support
Use another method to get the latest npm version from the registry that relies on the npm proxy configuration (npm outdated, npm view)

n0v1/get-npm-version-child-process