ObjectBuilder


ObjectBuilder is a type-safe implementation of Builder pattern with smart type inference.

Usage

ObjectBuilder.new

``typescript
import { ObjectBuilder } from 'typescript-object-builder';

type Endpoint = { url: string; method: string; description?: string };

const endpoint = ObjectBuilder.new()
.with('url', /status/)
.with('method', 'GET')
.with('description', 'Health check')
.build(); / OK - all of the required fields are set - build method becomes available /

const invalidEndpoint = ObjectBuilder.new()
.with('url', /status/)
.with('description', 'Health check')
.build(); / Error - build method is not available since one of the required fields is not set /
`

ObjectBuilder.fromBase

`typescript
import { ObjectBuilder } from 'typescript-object-builder';

type Endpoint = { url: string; method: string; description?: string };

const base = { url: '/status', description: 'Health check' };

const endpoint = ObjectBuilder.fromBase(base)
.with('method', 'GET')
.build(); / OK - all of the required fields are set (via base object and with) /

const invalidEndpoint = ObjectBuilder.fromBase(base)
.with('description', 'desc')
.build(); / Error - build method is not available since one of the required fields is not set /
`

ObjectBuilder.basedOn

`typescript
import { ObjectBuilder } from 'typescript-object-builder';

type Endpoint = { url: string; method: string; description?: string };

const base = { url: '/status', method: 'GET' };

const rewrittenEndpoint = ObjectBuilder.basedOn(base)
.with('method', 'GET')
.with('description', 'GET /status')
.with('url', '/status')
.build(); / Allows to take a base object and rewrite some or all of the properties /
`

Utility types

ObjectBuilder.PickNonOptionalFieldsKeys

`typescript
import type { PickNonOptionalFieldsKeys } from 'typescript-object-builder';

type Endpoint = { url: string; method: string; description?: string };

type T = PickNonOptionalFieldsKeys; / T is "url" | "method" /
`

ObjectBuilder.PickNonOptionalFields

`typescript
import type { PickNonOptionalFields } from 'typescript-object-builder';

type Endpoint = { url: string; method: string; description?: string };

type T = PickNonOptionalFields; / T is { url: string; method: string; } /
``

Features

- type-safe - it doesn't allow to call build method unless all non optional fields have been set
- smart type inference - builder offers (via autocomplete) to provide only those fields which have not been set yet