null belongsTo lookup results in empty sequelize instance

[mschipperheyn]

I'm not sure why this occurs and whether this is expected behavior.

I have implemented resolver to load associations in combination with dataloader.

I have an object with the following association:

Account.belongsTo(models.Photo, {
    foreignKey: 'photoId',
    constraints: false,
    onDelete: 'cascade',
    as: 'photo',
});

The resolver type for Account looks like this:

photo: resolver(() => models.Account.associations.photo),

When photoId is null, I get an empty sequelize instance (no dataValues) instead of null, resulting in errors. I ended up resolving this overwriting the resolver, but I'm still trying to get it. Doesn't seem to happen on other associations without constraints: false

import { resolver as coreResolver } from 'graphql-sequelize';
import getDataloader from './sequelize/middleware/dataloader';

const createNullAfter = result => {
    if (!Array.isArray(result)) {
        if (
            !result ||
            Object.entries(
                result.get({
                    plain: true,
                }),
            ).length === 0
        )
            return null;
        return result;
    }
    return result;
};

export const resolver = (Model, options) =>
    coreResolver(Model, {
        after: createNullAfter,
        ...options,
    });

[mickhansen]

A null value should simply result in a null result. I'm not sure if the issue here is in graphql-sequelize, dataloader-sequelize (if you use that) or in sequelize itself.

[mschipperheyn]

I do use dataloader-sequelize. So, it's weird. I thought so. I'll try to do some logging and try to figure it out.

[stale[bot]]

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