not including foreignKey in relation fields crashes loopback app

[ebarault]

consider the following relation:

        "conversation": {
            "type": "hasOne",
            "model": "Conversation",
            "foreignKey": "channelId",
            "scope": {
                "fields": ["id"]
            }
        }

note that the channelId foreignKey is missing in the fields filter: this gives the following error which just crashes the loopback app

2016-04-05T09:36:49.881Z pid:9557 worker:3 /var/lib/strong-pm/svc/1/work/8c5ceb3bf21d2beeb0c389ce02f87bad80f11ccc.1459848875604/node_modules/loopback-datasource-juggler/lib/include.js:812
2016-04-05T09:36:49.881Z pid:9557 worker:3             var objList = objTargetIdMap[targetId.toString()];
2016-04-05T09:36:49.882Z pid:9557 worker:3                                                  ^
2016-04-05T09:36:49.883Z pid:9557 worker:3 TypeError: Cannot read property 'toString' of undefined
2016-04-05T09:36:49.883Z pid:9557 worker:3     at linkOneToMany (/var/lib/strong-pm/svc/1/work/8c5ceb3bf21d2beeb0c389ce02f87bad80f11ccc.1459848875604/node_modules/loopback-datasource-juggler/lib/include.js:812:50)

adding the foreignKey in the fields filter solves the issue
"fields": ["id", "channelId"]

This is nonsense the app crashes for such reason.
Better than fixing, would you consider forcing the foreignKeys by default in fields filter ?

in my case, the relation

        "conversation": {
            "type": "hasOne",
            "model": "Conversation",
            "foreignKey": "channelId",
            "scope": {
                "fields": ["id"]
            }
        }

would implicitly traduce as a "fields": ["id", "channelId"] filter

[superkhau]

Can you provide a sample repo for me to reproduce the issue on my end?

[ebarault]

hi superkhau, i'll package a sample loopback app and send it through

[superkhau]

You can fork loopback-sandbox with just some dummy data. See https://github.com/strongloop/loopback/wiki/Reporting-issues#bug-report

[ebarault]

see this sample repo to reproduce the issue:

the sample has 2 models: parent and child with a hasOne relation from parent to child

as per parent.json the relation is defaulted to

"scope": {
        "include": [
            "child"
        ]
    },
    "relations": {
        "child": {
            "type": "hasOne",
            "model": "Child",
            "foreignKey": "parentId",
            "scope": {
                "fields": ["id"]
            }
        }
    }

note the missing parentId foreignKey in default fields

i created 2 boot scripts:

• one to create dummy data
• the other to run a query that will fail

simply launch node .
the app should crash with the incriminated error

just add the parentId foreignKey in fields included by default to have it work

i tested, it runs exactly the same if i don't include the relation and fields by default and specify them in the query

[jannyHou]

This is a duplicate issue of #779
To keep it easy to track, I will update the fix and move all discussion to that issue :)
I am closing this one, thanks for understanding.