modelMock.js

class QueryBuilderMock {
  static forClass() {
    return new this()
  }
  modelClass = () => ({ tableName: 'model_mock' })
  _mergeContext = jest.fn().mockReturnThis()
  _patch = jest.fn().mockReturnThis()
  _delete = jest.fn().mockReturnThis()
  _where = jest.fn().mockReturnThis()

  mergeContext(...args) {
    return this._mergeContext.apply(null, args)
  }

  patch(...args) {
    return this._patch.apply(null, args)
  }

  delete(...args) {
    return this._delete.apply(null, args)
  }

  where(...args) {
    return this._where.apply(null, args)
  }
}

class ModelMock {
  static query() {
    return this.QueryBuilder.forClass(this)
  }

  static get QueryBuilder() {
    return QueryBuilderMock
  }

  static namedFilters = {
    someFilter: () => {},
  }
}