@justwant/contract

Contract definitions for defineContract, fields, conforms, and validate. Schema-less, type-safe.

Installation

bun add @justwant/contract

Usage

import { defineContract, type Infer } from "@justwant/contract";
import { uuid, string, email } from "@justwant/contract/fields";

const UserContract = defineContract("users", {
  id: uuid().required().primaryKey(),
  email: email().required(),
  name: string().optional(),
});

type User = Infer<typeof UserContract>;

Mapping (contract key → column name)

By default, contract keys map 1:1 to column names. Override with defineContract(tableName, fields, options?):

defineContract("events", { user_id: string().required() });
// → column "user_id"

camelCase → snake_case: defaultMapping: "camelToSnake":

defineContract("events", { userId: string().required() }, { defaultMapping: "camelToSnake" });
// → column "user_id"

Override specific keys: mapping:

defineContract("events", { userId: string().required() }, {
  mapping: { userId: { name: "user_id" } },
});

Exports

• Main (@justwant/contract): defineContract, field, types, field builders, schemas, conforms, validate
• Fields (@justwant/contract/fields): uuid, string, email, etc. + schemas
• Conforms (@justwant/contract/conforms): conformsTo, assertTableConforms, tableConforms
• Validate (@justwant/contract/validate): validateContractData, ContractValidationError

Peer dependency

• @standard-schema/spec (optional) — for schema validation