fetch.js.flow

/* @flow */

type CredentialsType = "omit" | "same-origin" | "include";

type ResponseType = "basic" | "error";

type CacheType = "no-store" | "no-cache";

type BodyInit =
    | string
    | URLSearchParams
    | FormData
    | Blob
    | ArrayBuffer
    | ReadableStream
    | $ArrayBufferView;

type RequestInfo = Request | URL | string;

type RequestOptions = {|
    body?: ?BodyInit,
    credentials?: CredentialsType,
    headers?: HeadersInit,
    method?: string,
    mode?: string,
    referrer?: string,
    signal?: ?AbortSignal,
    cache?: ?CacheType,
|};

type ResponseOptions = {|
    status?: number,
    statusText?: string,
    headers?: HeadersInit,
    url?: string,
|};

type HeadersInit = Headers | { [string]: string };

// https://github.com/facebook/flow/blob/f68b89a5012bd995ab3509e7a41b7325045c4045/lib/bom.js#L902-L914
declare class Headers {
    @@iterator(): Iterator<[string, string]>;
    constructor(init?: HeadersInit): void;
    append(name: string, value: string): void;
    delete(name: string): void;
    entries(): Iterator<[string, string]>;
    forEach(
        (value: string, name: string, headers: Headers) => any,
        thisArg?: any
    ): void;
    get(name: string): null | string;
    has(name: string): boolean;
    keys(): Iterator<string>;
    set(name: string, value: string): void;
    values(): Iterator<string>;
}

// https://github.com/facebook/flow/pull/6548
interface AbortSignal {
    aborted: boolean;
    addEventListener(
        type: string,
        listener: (Event) => void,
        options?: EventListenerOptionsOrUseCapture
    ): void;
    removeEventListener(
        type: string,
        listener: (Event) => void,
        options?: EventListenerOptionsOrUseCapture
    ): void;
}

// https://github.com/facebook/flow/blob/f68b89a5012bd995ab3509e7a41b7325045c4045/lib/bom.js#L994-L1018
// unsupported in polyfill:
// - cache
// - integrity
// - redirect
// - referrerPolicy
declare class Request {
    constructor(input: RequestInfo, init?: RequestOptions): void;
    clone(): Request;

    url: string;

    credentials: CredentialsType;
    headers: Headers;
    method: string;
    mode: ModeType;
    referrer: string;
    signal: ?AbortSignal;

    // Body methods and attributes
    bodyUsed: boolean;

    arrayBuffer(): Promise<ArrayBuffer>;
    blob(): Promise<Blob>;
    formData(): Promise<FormData>;
    json(): Promise<any>;
    text(): Promise<string>;
}

// https://github.com/facebook/flow/blob/f68b89a5012bd995ab3509e7a41b7325045c4045/lib/bom.js#L968-L992
// unsupported in polyfill:
// - redirected
// - trailer
declare class Response {
    constructor(input?: ?BodyInit, init?: ResponseOptions): void;
    clone(): Response;
    static error(): Response;
    static redirect(url: string, status?: number): Response;

    type: ResponseType;
    url: string;
    ok: boolean;
    status: number;
    statusText: string;
    headers: Headers;

    // Body methods and attributes
    bodyUsed: boolean;
    body: ReadableStream;
    arrayBuffer(): Promise<ArrayBuffer>;
    blob(): Promise<Blob>;
    formData(): Promise<FormData>;
    json(): Promise<any>;
    text(): Promise<string>;
}

declare class AbortError extends Error {
    constructor(message?: string, name?: string): void;
}

declare module.exports: {
    fetch(input: RequestInfo, init?: RequestOptions): Promise<Response>,
    Headers: typeof Headers,
    Request: typeof Request,
    Response: typeof Response,
    AbortError: typeof AbortError,
};