Realm-js: node does not exit if realm-js is imported

[kvap]

Goals

Use realm in a cli program.

Expected Results

The program does its job and exits.

Actual Results

Node does not exit.

Steps to Reproduce

1. Import realm-js

Code Sample

require('realm');
console.log('hello');

It prints hello and hangs.

Version of Realm and Tooling

• Realm JS SDK Version: the issue first appeared in 1.12.0
• Node or React Native: Node 6.11.3
• Client OS & Version: macOS 10.12.6 and Debian 8

[kneth]

An ugly work-around is to call process.exit().

[ashwinphatak]

I can reproduce this locally. git bisect between 1.11.1 and 1.12.0 throws up https://github.com/realm/realm-js/commit/e18f54594fa54aa33b2b81f9471835c980309f21 as the offending commit, which is strange because it's just the 'bump version' commit without any code changes.

During the git bisect, I've run the following to get a clean build each time: git clean -xdf && git submodule update --init --recursive && npm install --build-from-source=realm

[kneth]

Interesting. It must indicate that changes in realm-js-private is the trouble-maker. That means, I have to examine the changes there more closely.

[blagoev]

I tried to debug the issue and I suspect the problem is within the AdminRealmListener changes but couldn't narrow down the issue yet.

[bmunkholm]

If this is not quick to solve, I think we can postpone this. It seems a minor annoyance only when using in node.js with a script.

[stigi]

This also prevents jest from exiting after finishing all tests.
Now this is a major annoyance as it prevents us from running tests agains in memory realms (or importing realm at all in our tests).

I created a demo project to demonstrate the issue: https://github.com/stigi/realm-require-issue

Edit: The workaround for jest is, running jest with the --forceExit flag. This triggers process.exit when all tests have been run.

[dehlen]

Any news on this one ? I can reproduce the described behavior with realm-js 2.3.1 and my jest tests won't terminate without adding the --forceExit hack.

[hallaji]

@stigi Thanks for that. Same here. The issue prevents Jest from exiting.

Jest: This usually means that there are asynchronous operations that weren't stopped in your tests.

[kneth]

Sorry, I haven't had time to prioritize it. In plain node scripts, calling process.exit() is fine but I can see the annoyance when you are testing.

[stigi]

@kneth Thanks for getting back to this issue.

I'm less worried about canceling async operations on my test stores than killing some script that works on production data.

[cyrusmg]

Any update on this issue ?

Building older versions of realm with Node v10 (LTS) crashes, building more recent version succeeds, but includes this bug which makes all realm tests fail (and using --forceExit hack for production code is really not the way to go). This means I am stuck with v8 until this issue is resolved.

[kneth]

@cyrusmg No updates to share - sorry. We are in the process to moving our code to a single repository (#2226) which I hope will help us to isolate the bug.

[kneth]

It looks like the issue has been resolved by a recent larger refactoring. At least, it doesn't happen to be when I use v2.28.0.