Mixins

Kosame does not provide its own implementation of the mixin mechanism; instead, it uses the standard TypeScript mixin function pattern to implement it.

How Mixins Work

TypeScript Mixins

Kosame has no mixin mechanism of its own, so you can use the standard TypeScript mixin pattern as-is.

function WithTimestamp<TBase extends Constructor<Model>>(Base: TBase) {
  abstract class WithTimestampMixin extends Base {
    get createdAtLabel() {
      return "Date and Time Created";
    }
  }
  return WithTimestampMixin;
}

Constructor<T>

The type for the standard mixin pattern is new (...args) => T, but since the Model itself is an abstract class, this type does not work. Therefore, Kosame resolves this issue by providing a dedicated type called Constructor<T> (abstract new (...args: any[]) => T).

SoftDeletable

SoftDeletable is a feature that, rather than completely deleting data from the database, stores a date and time in a column such as deletedAt to make it appear as if the data has been deleted.

Instructions for Use

Define the deletedAt column in the table using deletedAtColumn(), and apply it to the model using SoftDeletable(Model). Import deletedAtColumn() from sources such as kosame/pg, depending on the dialect.

import { Model, SoftDeletable } from "kosame";
import { deletedAtColumn } from "kosame/pg";

export const usersTable = pgTable("users", {
  id: serial("id").primaryKey(),
  name: text("name").notNull(),
  deletedAt: deletedAtColumn(),
});

class User extends SoftDeletable(Model) {
  static table = usersTable;
}

delete() and hardDelete()

delete() does not actually delete the record; instead, it updates the deletedAt field with a date and time. To perform a permanent deletion, use hardDelete().

Automatic Exclusion When Fetching

For models that have SoftDeletable applied, deleted rows are automatically excluded from both find() queries and relations retrieved via include. Simply having a column named deletedAt is not enough to exclude these rows; this behavior is only effective when SoftDeletable is applied.