nestRemoting() throws TypeError without {hooks:false} hack

[timneedham]

Hi,

Really loving Loopback and the community... but just can't crack this. Spent a few days in the docs and can't find anything obviously wrong...

If I call nestRemoting() on a model with the option hooks:false set, then things are fine.
Having to provide options isn't mentioned in the docs... so I guess this is masking a deeper problem?

If planet is the top-level model, which hasMany moon[s], which in-turn hasMany crater[s]...

And we've planet.nestRemoting('moons'), then posting to /api/planets, with the hooks:false option omitted, results in:

TypeError: Cannot read property 'moon' of undefined
    at EventEmitter.<anonymous> (/home/tim/GithubProjects/nest-remoting-issue/node_modules/loopback/lib/model.js:809:58)
    at EventEmitter.g (events.js:260:16)
    at emitThree (events.js:97:13)
    at EventEmitter.emit (events.js:175:7)
    at /home/tim/GithubProjects/nest-remoting-issue/node_modules/loopback/lib/application.js:279:22
    at Array.forEach (native)
    at EventEmitter.app.handler (/home/tim/GithubProjects/nest-remoting-issue/node_modules/loopback/lib/application.js:278:21)
    at /home/tim/GithubProjects/nest-remoting-issue/node_modules/loopback/server/middleware/rest.js:65:20
    at /home/tim/GithubProjects/nest-remoting-issue/node_modules/loopback/server/middleware/rest.js:72:7
    at iterate (/home/tim/GithubProjects/nest-remoting-issue/node_modules/async/lib/async.js:146:13)

Which seems to point to something not being quite right with the way our remotes are set-up? This is the line in Model.nestRemoting that fails:

var beforeListeners = remotes.listenerTree.before[toModelName] || {};

• ...because remotes.listenerTree is an empty object with no before key.
• I've made a repo to replicate this issue here.
• And this might be a clue: once that first post fails, any subsequent posts to the same endpoint work just fine!

I guess I'm doing something stupid/in the wrong order/wrong timing when booting, but just can't find it.

We would really appreciate some assistance as this is (hopefully) the last snag before we commit to Loopback in our next project.

Thanks in advance, keep up the great work!

Tim

[gunjpan]

@timneedham : Hi Tim, I'm investigating this issue. I created a sample application using LoopBack Sandbox and Model.nestRemoting('relation') is working fine. Take a look here.
The scaffold works fine. I believe, the error you're facing could be due to bootstrapping of the application. I tried different scenarios on your sample repo, but it didn't work.
Could you please compare them and see what's happening from your side?

[timneedham]

@gunjpan : Hi Gunjan, thank you for taking the time to create the sandbox... I'll compare the two repos and report back.
Tim

[timneedham]

@gunjpan
Hi Gunjan... Got it.... I think!

The issue seems to be I don't add a loopback.User model to my app... and Loopbox Sandbox does.

The User model seems to ensure the remotes.listenerTree is no longer empty. This in-turn allows nestRemoting() to work without throwing a TypeError.

So simply adding:

var User = app.model(loopback.User, {dataSource: 'mem'});

...makes the app in my demo repo work fine!

• I've raised PR Should use copy of remotes.listenerTree? #1966 ... I think this behaviour might be down to a small bug?

Thanks again for your assistance.

Tim

[gunjpan]

@timneedham : I verified your comments by removing Usermodel from the sandbox. I'm promoting this issue as a bug and thank you for a PR. It will be reviewed and merged if approved.
Thanks again!