[multivendor] Maximum call stack size exceeded upon setting shipping method

[twlite]

Describe the bug
Sometimes vendure throws call stack overflow error when setting a shipping method on multivendor plugin. The error seems to occur at

vendure/packages/dev-server/example-plugins/multivendor-plugin/config/mv-shipping-line-assignment-strategy.ts

Line 26 in a98fed0

await this.entityHydrator.hydrate(ctx, shippingLine, { relations: ['shippingMethod.channels'] });

where the mergeDeep function invoked by EntityHydrator goes too deep.

To Reproduce
Steps to reproduce the behavior:
The issue does not occur 100% of the time. But when it does, it happens after setting shipping method on an order.

Expected behavior
It should not cause stack overflow error.

Environment (please complete the following information):

• @vendure/core version: 3.1.2
• Nodejs version: 22.12.0
• Database (mysql/postgres etc): postgres

Additional context
This issue started appearing out of the blue. The related discord thread is #1336949445153263667

[dylviz]

We ran into this issue recently as well in multiple places. Our fix at the moment is to break up loading the Channels relation in a separate call. Not the most optimal in my opinion.

[twlite]

We ran into this issue recently as well in multiple places. Our fix at the moment is to break up loading the Channels relation in a separate call. Not the most optimal in my opinion.

yes, at the moment that's what I'm doing

[michaelbromley]

@dylviz for you did it happen consistently? The original issue mentions it only happens sometimes.

If we can isolate some consistently reproducible example code, it will make resolving much faster, plus we can also create a test for it to prevent any future regressions once fixed.

[dylviz]

@dylviz for you did it happen consistently? The original issue mentions it only happens sometimes.

If we can isolate some consistently reproducible example code, it will make resolving much faster, plus we can also create a test for it to prevent any future regressions once fixed.

From the frontend, I can get this consistently, but I'm not clear what's happening in the backend that is causing this. I can share a few findings as I go through it.

Right now, I'm thinking the issue is here:

vendure/packages/core/src/service/helpers/utils/tree-relations-qb-joiner.ts

Line 85 in 006086b

isTreeEntityMetadata(currentMetadata) || sourceMetadataIsTree || parentMetadataIsTree;

When the processRelation method is called with the currentPath as "ShippingMethod.Channels", then currentMetaDataisTree returns false. It also returns false when currentPath is "ShippingMethod":

CurrentMetaData:

tableMetadataArgs =
{target: ƒ, name: undefined, type: 'regular', orderBy: undefined, engine: undefined, …}
tableName =
'shipping_line'
tableNameWithoutPrefix =
'shipping_line'
tablePath =
'public.shipping_line'
tableType =
'regular'
target =
class ShippingLine
targetName =
'ShippingLine'
treeChildrenRelation =
undefined
treeLevelColumn =
undefined
treeOptions =
undefined
treeParentRelation =
undefined
treeType =
undefined
uniques =
(0) []
updateDateColumn =
ColumnMetadata {@instanceof: Symbol(ColumnMetadata), length: '', isPrimary: false, isGenerated: false, isNullable: false, …}
versionColumn =
undefined
withoutRowid =
false
[[Prototype]] =
Object

Is anything here a potential red flag? I might be stuck here