Parent.hasMany(Child, as: { singular: string; plural: string;})

Dad.hasOne(Mum, as: 'Mummy')

Dad.hasOne(Mum, as: { singular: 'Mummy', plural: 'Mummies' }

D:ProjectsSequelizenode_modulesinflectionlibinflection.js:594
        var ignore = ( inflector.indexOf( skip, str.toLowerCase()) > -1 );

TypeError: str.toLowerCase is not a function
    at Object._apply_rules (D:ProjectsSequelizenode_modulesinflectionlibinflection.js:594:53)
    at Object.singularize (D:ProjectsSequelizenode_modulesinflectionlibinflection.js:692:24)
    at Object.singularize (D:ProjectsSequelizenode_modulessequelizelibutils.js:285:21)
    at new HasOne (D:ProjectsSequelizenode_modulessequelizelibassociationshas-one.js:45:37)
    at Function.<anonymous> (D:ProjectsSequelizenode_modulessequelizelibassociationsmixin.js:92:25)
    at Function.Dads.associate.models [as associate] (D:ProjectsSequelizedistmodelsschemaDad.js:17:20)

Service_User
Service_Permission
Service_Activity

connection = new Sequelize();

models: {
  Service_User: connection.import(path/to/schema)
  Service_Permission: connection.import(path/to/schema)
  Service_Activity: connection.import(path/to/schema)
}

models.Service_User.create({});

This can be done by not utilising alias:

Dad.hasOne(Mum);

const dad = models.Dad.findOne(...);

// dad.getMum()
// is this legal, definitely not safe right?!
const mum = dad.[`get${models.Dad.options.name.singular}`]();

const MumAlias = { singular: 'Mummy', plural: 'Mummies' };

MumsClub.hasMany(Mum, { as: MumAlias })
Dad.hasOne(Mum, { as: MumAlias })

const mumsClub = models.MumsClub.findOne(...);
const dad = models.Dad.findOne(...);

// dad.getMummy()
const mum = dad[`get${MumAlias.singular}`];

// mumsClub.setMummies()
mumsClub[`set${MumAlias.plural}`]([mum1, mum2, mum3, ...]);