Module
🌳 Tiny & elegant JavaScript HTTP client based on the browser Fetch API
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320import {HTTPError} from '../errors/HTTPError.js';import {TimeoutError} from '../errors/TimeoutError.js';import type {Hooks} from '../types/hooks.js';import type {Input, InternalOptions, NormalizedOptions, Options, SearchParamsInit} from '../types/options.js';import {ResponsePromise} from '../types/response.js';import {deepMerge, mergeHeaders} from '../utils/merge.js';import {normalizeRequestMethod, normalizeRetryOptions} from '../utils/normalize.js';import {delay, timeout, TimeoutOptions} from '../utils/time.js';import {ObjectEntries} from '../utils/types.js';import {maxSafeTimeout, responseTypes, stop, supportsAbortController, supportsFormData, supportsStreams} from './constants.js';
export class Ky { // eslint-disable-next-line @typescript-eslint/promise-function-async static create(input: Input, options: Options): ResponsePromise { const ky = new Ky(input, options);
const fn = async (): Promise<Response> => { if (ky._options.timeout > maxSafeTimeout) { throw new RangeError(`The \`timeout\` option cannot be greater than ${maxSafeTimeout}`); }
// Delay the fetch so that body method shortcuts can set the Accept header await Promise.resolve(); let response = await ky._fetch();
for (const hook of ky._options.hooks.afterResponse) { // eslint-disable-next-line no-await-in-loop const modifiedResponse = await hook( ky.request, ky._options as NormalizedOptions, ky._decorateResponse(response.clone()), );
if (modifiedResponse instanceof globalThis.Response) { response = modifiedResponse; } }
ky._decorateResponse(response);
if (!response.ok && ky._options.throwHttpErrors) { let error = new HTTPError(response, ky.request, (ky._options as unknown) as NormalizedOptions);
for (const hook of ky._options.hooks.beforeError) { // eslint-disable-next-line no-await-in-loop error = await hook(error); }
throw error; }
// If `onDownloadProgress` is passed, it uses the stream API internally /* istanbul ignore next */ if (ky._options.onDownloadProgress) { if (typeof ky._options.onDownloadProgress !== 'function') { throw new TypeError('The `onDownloadProgress` option must be a function'); }
if (!supportsStreams) { throw new Error('Streams are not supported in your environment. `ReadableStream` is missing.'); }
return ky._stream(response.clone(), ky._options.onDownloadProgress); }
return response; };
const isRetriableMethod = ky._options.retry.methods.includes(ky.request.method.toLowerCase()); const result = (isRetriableMethod ? ky._retry(fn) : fn()) as ResponsePromise;
for (const [type, mimeType] of Object.entries(responseTypes) as ObjectEntries<typeof responseTypes>) { result[type] = async () => { // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing ky.request.headers.set('accept', ky.request.headers.get('accept') || mimeType);
const awaitedResult = await result; const response = awaitedResult.clone();
if (type === 'json') { if (response.status === 204) { return ''; }
if (options.parseJson) { return options.parseJson(await response.text()); } }
return response[type](); }; }
return result; }
public request: Request; protected abortController?: AbortController; protected _retryCount = 0; protected _input: Input; protected _options: InternalOptions;
// eslint-disable-next-line complexity constructor(input: Input, options: Options = {}) { this._input = input; this._options = { // TODO: credentials can be removed when the spec change is implemented in all browsers. Context: https://www.chromestatus.com/feature/4539473312350208 credentials: (this._input as Request).credentials || 'same-origin', ...options, headers: mergeHeaders((this._input as Request).headers, options.headers), hooks: deepMerge<Required<Hooks>>( { beforeRequest: [], beforeRetry: [], beforeError: [], afterResponse: [], }, options.hooks, ), method: normalizeRequestMethod(options.method ?? (this._input as Request).method), // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing prefixUrl: String(options.prefixUrl || ''), retry: normalizeRetryOptions(options.retry), throwHttpErrors: options.throwHttpErrors !== false, timeout: typeof options.timeout === 'undefined' ? 10_000 : options.timeout, fetch: options.fetch ?? globalThis.fetch.bind(globalThis), };
if (typeof this._input !== 'string' && !(this._input instanceof URL || this._input instanceof globalThis.Request)) { throw new TypeError('`input` must be a string, URL, or Request'); }
if (this._options.prefixUrl && typeof this._input === 'string') { if (this._input.startsWith('/')) { throw new Error('`input` must not begin with a slash when using `prefixUrl`'); }
if (!this._options.prefixUrl.endsWith('/')) { this._options.prefixUrl += '/'; }
this._input = this._options.prefixUrl + this._input; }
if (supportsAbortController) { this.abortController = new globalThis.AbortController(); if (this._options.signal) { this._options.signal.addEventListener('abort', () => { this.abortController!.abort(); }); }
this._options.signal = this.abortController.signal; }
this.request = new globalThis.Request(this._input as RequestInfo, this._options as RequestInit);
if (this._options.searchParams) { // eslint-disable-next-line unicorn/prevent-abbreviations const textSearchParams = typeof this._options.searchParams === 'string' ? this._options.searchParams.replace(/^\?/, '') : new URLSearchParams(this._options.searchParams as unknown as SearchParamsInit).toString(); // eslint-disable-next-line unicorn/prevent-abbreviations const searchParams = '?' + textSearchParams; const url = this.request.url.replace(/(?:\?.*?)?(?=#|$)/, searchParams);
// To provide correct form boundary, Content-Type header should be deleted each time when new Request instantiated from another one if ( ((supportsFormData && this._options.body instanceof globalThis.FormData) || this._options.body instanceof URLSearchParams) && !(this._options.headers && (this._options.headers as Record<string, string>)['content-type']) ) { this.request.headers.delete('content-type'); }
this.request = new globalThis.Request(new globalThis.Request(url, this.request), this._options as RequestInit); }
if (this._options.json !== undefined) { this._options.body = JSON.stringify(this._options.json); this.request.headers.set('content-type', this._options.headers.get('content-type') ?? 'application/json'); this.request = new globalThis.Request(this.request, {body: this._options.body}); } }
protected _calculateRetryDelay(error: unknown) { this._retryCount++;
if (this._retryCount < this._options.retry.limit && !(error instanceof TimeoutError)) { if (error instanceof HTTPError) { if (!this._options.retry.statusCodes.includes(error.response.status)) { return 0; }
const retryAfter = error.response.headers.get('Retry-After'); if (retryAfter && this._options.retry.afterStatusCodes.includes(error.response.status)) { let after = Number(retryAfter); if (Number.isNaN(after)) { after = Date.parse(retryAfter) - Date.now(); } else { after *= 1000; }
if (typeof this._options.retry.maxRetryAfter !== 'undefined' && after > this._options.retry.maxRetryAfter) { return 0; }
return after; }
if (error.response.status === 413) { return 0; } }
const BACKOFF_FACTOR = 0.3; return BACKOFF_FACTOR * (2 ** (this._retryCount - 1)) * 1000; }
return 0; }
protected _decorateResponse(response: Response): Response { if (this._options.parseJson) { response.json = async () => this._options.parseJson!(await response.text()); }
return response; }
protected async _retry<T extends (...args: any) => Promise<any>>(fn: T): Promise<ReturnType<T> | void> { try { return await fn(); // eslint-disable-next-line @typescript-eslint/no-implicit-any-catch } catch (error) { const ms = Math.min(this._calculateRetryDelay(error), maxSafeTimeout); if (ms !== 0 && this._retryCount > 0) { await delay(ms);
for (const hook of this._options.hooks.beforeRetry) { // eslint-disable-next-line no-await-in-loop const hookResult = await hook({ request: this.request, options: (this._options as unknown) as NormalizedOptions, error: error as Error, retryCount: this._retryCount, });
// If `stop` is returned from the hook, the retry process is stopped if (hookResult === stop) { return; } }
return this._retry(fn); }
throw error; } }
protected async _fetch(): Promise<Response> { for (const hook of this._options.hooks.beforeRequest) { // eslint-disable-next-line no-await-in-loop const result = await hook(this.request, (this._options as unknown) as NormalizedOptions);
if (result instanceof Request) { this.request = result; break; }
if (result instanceof Response) { return result; } }
if (this._options.timeout === false) { return this._options.fetch(this.request.clone()); }
return timeout(this.request.clone(), this.abortController, this._options as TimeoutOptions); }
/* istanbul ignore next */ protected _stream(response: Response, onDownloadProgress: Options['onDownloadProgress']) { const totalBytes = Number(response.headers.get('content-length')) || 0; let transferredBytes = 0;
return new globalThis.Response( new globalThis.ReadableStream({ async start(controller) { const reader = response.body!.getReader();
if (onDownloadProgress) { onDownloadProgress({percent: 0, transferredBytes: 0, totalBytes}, new Uint8Array()); }
async function read() { const {done, value} = await reader.read(); if (done) { controller.close(); return; }
if (onDownloadProgress) { transferredBytes += value.byteLength; const percent = totalBytes === 0 ? 0 : transferredBytes / totalBytes; onDownloadProgress({percent, transferredBytes, totalBytes}, value); }
controller.enqueue(value); await read(); }
await read(); }, }), ); }}