Type Definitions

This page documents the key TypeScript interfaces and types used across the Fetcher ecosystem. Types are organized by package and category.

Core Types (`@ahoo-wang/fetcher`)

Utility Types

Source: packages/fetcher/src/types.ts

Type	Signature	Description
`PartialBy<T, K>`	`Omit<T, K> & Partial<Pick<T, K>>`	Make specified keys optional
`RequiredBy<T, K>`	`Omit<T, K> & Required<Pick<T, K>>`	Make specified keys required
`RemoveReadonlyFields<T>`	Mapped type	Remove all readonly properties

NamedCapable

typescript

interface NamedCapable {
  name: string;
}

Source: packages/fetcher/src/types.ts:141

FetcherConfigurer

Interface for objects that configure a Fetcher instance:

typescript

interface FetcherConfigurer {
  applyTo(fetcher: Fetcher): void;
}

Source: packages/fetcher/src/types.ts:248

Request Types

HttpMethod

typescript

enum HttpMethod {
  GET = 'GET',
  POST = 'POST',
  PUT = 'PUT',
  DELETE = 'DELETE',
  PATCH = 'PATCH',
  HEAD = 'HEAD',
  OPTIONS = 'OPTIONS',
  TRACE = 'TRACE',
}

Source: packages/fetcher/src/fetchRequest.ts:37

RequestHeaders

typescript

interface RequestHeaders {
  'Content-Type'?: string;
  Accept?: string;
  Authorization?: string;
  [key: string]: string | undefined;
}

Source: packages/fetcher/src/fetchRequest.ts:68

RequestBodyType

typescript

type RequestBodyType = BodyInit | Record<string, any> | string | null;

Source: packages/fetcher/src/fetchRequest.ts:88

FetchRequestInit

typescript

interface FetchRequestInit<BODY extends RequestBodyType = RequestBodyType>
  extends TimeoutCapable, RequestHeadersCapable, UrlParamsCapable,
    Omit<RequestInit, 'body' | 'headers'> {
  body?: BODY;
  abortController?: AbortController;
}

Source: packages/fetcher/src/fetchRequest.ts:112

FetchRequest

typescript

interface FetchRequest<BODY extends RequestBodyType = RequestBodyType>
  extends FetchRequestInit<BODY> {
  url: string;
}

Source: packages/fetcher/src/fetchRequest.ts:176

UrlParams

typescript

interface UrlParams {
  path?: Record<string, any>;
  query?: Record<string, any>;
}

Source: packages/fetcher/src/urlBuilder.ts:27

Configuration Types

FetcherOptions

typescript

interface FetcherOptions extends BaseURLCapable, RequestHeadersCapable, TimeoutCapable {
  urlTemplateStyle?: UrlTemplateStyle;
  interceptors?: InterceptorManager;
  validateStatus?: ValidateStatus;
}

Source: packages/fetcher/src/fetcher.ts:51

RequestOptions

typescript

interface RequestOptions extends AttributesCapable, ResultExtractorCapable {}

Source: packages/fetcher/src/fetcher.ts:94

ValidateStatus

typescript

type ValidateStatus = (status: number) => boolean;

Source: packages/fetcher/src/validateStatusInterceptor.ts:62

Capability Interfaces

These interfaces define "capabilities" that types can implement:

Interface	Property	Type	Source
`BaseURLCapable`	`baseURL`	`string`	`fetchRequest.ts:23`
`RequestHeadersCapable`	`headers?`	`RequestHeaders`	`fetchRequest.ts:81`
`TimeoutCapable`	`timeout?`	`number`	`timeout.ts`
`UrlParamsCapable`	`urlParams?`	`UrlParams`	`fetchRequest.ts:48`
`UrlBuilderCapable`	`urlBuilder`	`UrlBuilder`	`urlBuilder.ts:154`
`ResultExtractorCapable`	`resultExtractor?`	`ResultExtractor<any>`	`resultExtractor.ts:31`
`AttributesCapable`	`attributes?`	`Record<string, any> \| Map<string, any>`	`fetchExchange.ts:23`

Interceptor Types

Interceptor

typescript

interface Interceptor extends NamedCapable, OrderedCapable {
  readonly name: string;
  readonly order: number;
  intercept(exchange: FetchExchange): void | Promise<void>;
}

Source: packages/fetcher/src/interceptor.ts:44

Specialized Interceptor Interfaces

typescript

interface RequestInterceptor extends Interceptor {}
interface ResponseInterceptor extends Interceptor {}
interface ErrorInterceptor extends Interceptor {}

All three extend Interceptor without adding new members. They exist for semantic clarity and type discrimination.

Source: packages/fetcher/src/interceptor.ts:111-164

Result Extractor Types

typescript

interface ResultExtractor<R> {
  (exchange: FetchExchange): R | Promise<R>;
}

Source: packages/fetcher/src/resultExtractor.ts:23

Error Types

Type Hierarchy

mermaid

classDiagram
    class Error {
        +message: string
        +stack?: string
    }
    class FetcherError {
        +cause?: Error | unknown
        +name: "FetcherError"
    }
    class ExchangeError {
        +exchange: FetchExchange
        +name: "ExchangeError"
    }
    class HttpStatusValidationError {
        +name: "HttpStatusValidationError"
    }
    class AutoGenerated {
        +name: "AutoGenerated"
    }

    Error <|-- FetcherError
    FetcherError <|-- ExchangeError
    ExchangeError <|-- HttpStatusValidationError
    Error <|-- AutoGenerated

    style Error fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style FetcherError fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style ExchangeError fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style HttpStatusValidationError fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style AutoGenerated fill:#2d333b,stroke:#6d5dfc,color:#e6edf3

Class	Package	Source
`FetcherError`	fetcher	`fetcherError.ts:37`
`ExchangeError`	fetcher	`fetcherError.ts:86`
`HttpStatusValidationError`	fetcher	`validateStatusInterceptor.ts:27`
`AutoGenerated`	decorator	`generated.ts:25`

EventBus Types (`@ahoo-wang/fetcher-eventbus`)

Source: packages/eventbus/src/types.ts

EventHandler

typescript

interface EventHandler<EVENT> extends NamedCapable, OrderedCapable {
  once?: boolean;
  handle(event: EVENT): void | Promise<void>;
}

EventBus

typescript

class EventBus<Events extends Record<EventType, unknown>> {
  on<Key extends EventType>(type: Key, handler: EventHandler<Events[Key]>): boolean;
  off<Key extends EventType>(type: Key, name: string): boolean;
  emit<Key extends EventType>(type: Key, event: Events[Key]): void | Promise<void>;
  destroy(): void;
}

Source: packages/eventbus/src/eventBus.ts:35

React Hook Types (`@ahoo-wang/fetcher-react`)

PromiseStatus

typescript

enum PromiseStatus {
  IDLE = 'idle',
  LOADING = 'loading',
  SUCCESS = 'success',
  ERROR = 'error',
}

Source: packages/react/src/core/usePromiseState.ts:22

PromiseState

typescript

interface PromiseState<R, E = unknown> {
  status: PromiseStatus;
  loading: boolean;
  result: R | undefined;
  error: E | undefined;
}

Source: packages/react/src/core/usePromiseState.ts:29

PromiseSupplier

typescript

type PromiseSupplier<R> = (abortController: AbortController) => Promise<R>;

Source: packages/react/src/core/useExecutePromise.ts:51

QueryOptions

typescript

interface QueryOptions<Q> {
  initialQuery?: Q;
  query?: Q;
}

Source: packages/react/src/core/useQueryState.ts:17

AutoExecuteCapable

typescript

interface AutoExecuteCapable {
  autoExecute?: boolean; // Defaults to true
}

Source: packages/react/src/types.ts:20

Decorator Types (`@ahoo-wang/fetcher-decorator`)

ParameterType

typescript

enum ParameterType {
  PATH = 'path',
  QUERY = 'query',
  HEADER = 'header',
  BODY = 'body',
  REQUEST = 'request',
  ATTRIBUTE = 'attribute',
}

Source: packages/decorator/src/parameterDecorator.ts:19

ParameterMetadata

typescript

interface ParameterMetadata {
  type: ParameterType;
  name?: string;
  index: number;
}

Source: packages/decorator/src/parameterDecorator.ts:136

EndpointReturnType

typescript

enum EndpointReturnType {
  EXCHANGE = 'Exchange',
  RESULT = 'Result',
}

Source: packages/decorator/src/endpointReturnTypeCapable.ts:14

ParameterRequest

typescript

interface ParameterRequest<BODY extends RequestBodyType = RequestBodyType>
  extends FetchRequestInit<BODY>, PathCapable {}

Source: packages/decorator/src/parameterDecorator.ts:352

Type Relationship Diagram

mermaid

graph TB
    subgraph sg_1 ["Fetcher Options"]
        FO["FetcherOptions"]
        RO["RequestOptions"]
        VS["ValidateStatus"]
    end

    subgraph sg_2 ["Request Types"]
        FRI["FetchRequestInit"]
        FR["FetchRequest"]
        UP["UrlParams"]
        RH["RequestHeaders"]
    end

    subgraph sg_3 ["Exchange"]
        FE["FetchExchange"]
        FEI["FetchExchangeInit"]
    end

    subgraph sg_4 ["Interceptors"]
        INT["Interceptor"]
        RI["InterceptorRegistry"]
        IM["InterceptorManager"]
    end

    subgraph sg_5 ["Extractors"]
        RE["ResultExtractor&lt;R&gt;"]
        RES["ResultExtractors"]
    end

    subgraph sg_6 ["Errors"]
        FErr["FetcherError"]
        EErr["ExchangeError"]
        HErr["HttpStatusValidationError"]
    end

    FO -->|"creates"| IM
    FO -->|"configures"| VS
    FRI -->|"extends"| FR
    FR -->|"flows through"| FE
    FE -->|"processed by"| IM
    IM -->|"manages"| RI
    RI -->|"executes"| INT
    FE -->|"extracted by"| RE
    FErr -->|"extended by"| EErr
    EErr -->|"extended by"| HErr

    style FO fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style FR fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style FE fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style IM fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style INT fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style RE fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style FErr fill:#2d333b,stroke:#6d5dfc,color:#e6edf3

Global Type Augmentation

Fetcher augments the global Response interface with a generic json<T>() method:

typescript

declare global {
  interface Response {
    json<T = any>(): Promise<T>;
  }
}

Source: packages/fetcher/src/types.ts:162

React Hook Type Composition

mermaid

graph TD
    subgraph sg_1 ["usePromiseState"]
        PS["PromiseState&lt;R, E&gt;"]
        PSE["UsePromiseStateReturn"]
    end

    subgraph sg_2 ["useExecutePromise"]
        EPS["UseExecutePromiseOptions"]
        EPR["UseExecutePromiseReturn"]
    end

    subgraph sg_3 ["useQuery"]
        QO["UseQueryOptions"]
        QR["UseQueryReturn"]
    end

    subgraph sg_4 ["useFetcher"]
        FO["UseFetcherOptions"]
        FR["UseFetcherReturn"]
    end

    PS --> PSE
    PSE --> EPR
    EPS --> EPR
    EPS --> QO
    EPR --> QR
    QO --> QR
    EPS --> FO
    EPR --> FR

    style PS fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style PSE fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style EPR fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style QR fill:#2d333b,stroke:#6d5dfc,color:#e6edf3
    style FR fill:#2d333b,stroke:#6d5dfc,color:#e6edf3

Fetcher Client API -- How to use these types in practice
Decorators API -- Decorator-specific types
React Hooks API -- React hook types
API Overview -- Package summary

Type Definitions ​

Core Types (@ahoo-wang/fetcher) ​

Utility Types ​

NamedCapable ​

FetcherConfigurer ​

Request Types ​

HttpMethod ​

RequestHeaders ​

RequestBodyType ​

FetchRequestInit ​

FetchRequest ​

UrlParams ​

Configuration Types ​

FetcherOptions ​

RequestOptions ​

ValidateStatus ​

Capability Interfaces ​

Interceptor Types ​

Interceptor ​

Specialized Interceptor Interfaces ​

Result Extractor Types ​

Error Types ​

Type Hierarchy ​

EventBus Types (@ahoo-wang/fetcher-eventbus) ​

EventHandler ​

EventBus ​

React Hook Types (@ahoo-wang/fetcher-react) ​

PromiseStatus ​

PromiseState ​

PromiseSupplier ​

QueryOptions ​

AutoExecuteCapable ​

Decorator Types (@ahoo-wang/fetcher-decorator) ​

ParameterType ​

ParameterMetadata ​

EndpointReturnType ​

ParameterRequest ​

Type Relationship Diagram ​

Global Type Augmentation ​

React Hook Type Composition ​

Related Pages ​

Type Definitions

Core Types (`@ahoo-wang/fetcher`)

Utility Types

NamedCapable

FetcherConfigurer

Request Types

HttpMethod

RequestHeaders

RequestBodyType

FetchRequestInit

FetchRequest

UrlParams

Configuration Types

FetcherOptions

RequestOptions

ValidateStatus

Capability Interfaces

Interceptor Types

Interceptor

Specialized Interceptor Interfaces

Result Extractor Types

Error Types

Type Hierarchy

EventBus Types (`@ahoo-wang/fetcher-eventbus`)

EventHandler

EventBus

React Hook Types (`@ahoo-wang/fetcher-react`)

PromiseStatus

PromiseState

PromiseSupplier

QueryOptions

AutoExecuteCapable

Decorator Types (`@ahoo-wang/fetcher-decorator`)

ParameterType

ParameterMetadata

EndpointReturnType

ParameterRequest

Type Relationship Diagram

Global Type Augmentation

React Hook Type Composition

Related Pages