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x/hono/context.ts

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import type { Runtime } from './helper/adapter/index.ts'import type { HonoRequest } from './request.ts'import type { Env, FetchEventLike, NotFoundHandler, Input, TypedResponse } from './types.ts'import type { CookieOptions } from './utils/cookie.ts'import { serialize } from './utils/cookie.ts'import { resolveStream } from './utils/html.ts'import type { StatusCode } from './utils/http-status.ts'import { StreamingApi } from './utils/stream.ts'import type { JSONValue, InterfaceToType, JSONParsed } from './utils/types.ts'
type HeaderRecord = Record<string, string | string[]>type Data = string | ArrayBuffer | ReadableStream
export interface ExecutionContext { waitUntil(promise: Promise<unknown>): void passThroughOnException(): void}
export interface ContextVariableMap {}
export interface ContextRenderer {}interface DefaultRenderer { (content: string | Promise<string>): Response | Promise<Response>}
export type Renderer = ContextRenderer extends Function ? ContextRenderer : DefaultRenderer
interface Get<E extends Env> { <Key extends keyof ContextVariableMap>(key: Key): ContextVariableMap[Key] <Key extends keyof E['Variables']>(key: Key): E['Variables'][Key]}
interface Set<E extends Env> { <Key extends keyof ContextVariableMap>(key: Key, value: ContextVariableMap[Key]): void <Key extends keyof E['Variables']>(key: Key, value: E['Variables'][Key]): void}
interface NewResponse { (data: Data | null, status?: StatusCode, headers?: HeaderRecord): Response (data: Data | null, init?: ResponseInit): Response}
interface BodyRespond extends NewResponse {}
interface TextRespond { (text: string, status?: StatusCode, headers?: HeaderRecord): Response (text: string, init?: ResponseInit): Response}
interface JSONRespond { <T>( object: InterfaceToType<T> extends JSONValue ? T : JSONValue, status?: StatusCode, headers?: HeaderRecord ): Response & TypedResponse< InterfaceToType<T> extends JSONValue ? JSONValue extends InterfaceToType<T> ? never : JSONParsed<T> : never > <T>(object: InterfaceToType<T> extends JSONValue ? T : JSONValue, init?: ResponseInit): Response & TypedResponse< InterfaceToType<T> extends JSONValue ? JSONValue extends InterfaceToType<T> ? never : JSONParsed<T> : never >}
interface HTMLRespond { (html: string | Promise<string>, status?: StatusCode, headers?: HeaderRecord): | Response | Promise<Response> (html: string | Promise<string>, init?: ResponseInit): Response | Promise<Response>}
type ContextOptions<E extends Env> = { env: E['Bindings'] executionCtx?: FetchEventLike | ExecutionContext | undefined notFoundHandler?: NotFoundHandler<E>}
const TEXT_PLAIN = 'text/plain; charset=UTF-8'
export class Context< // eslint-disable-next-line @typescript-eslint/no-explicit-any E extends Env = any, // eslint-disable-next-line @typescript-eslint/no-explicit-any P extends string = any, I extends Input = {}> { req: HonoRequest<P, I['out']> env: E['Bindings'] = {} private _var: E['Variables'] = {} finalized: boolean = false error: Error | undefined = undefined
#status: StatusCode = 200 #executionCtx: FetchEventLike | ExecutionContext | undefined #headers: Headers | undefined = undefined #preparedHeaders: Record<string, string> | undefined = undefined #res: Response | undefined #isFresh = true private renderer: Renderer = (content: string | Promise<string>) => this.html(content) private notFoundHandler: NotFoundHandler<E> = () => new Response()
constructor(req: HonoRequest<P, I['out']>, options?: ContextOptions<E>) { this.req = req if (options) { this.#executionCtx = options.executionCtx this.env = options.env if (options.notFoundHandler) { this.notFoundHandler = options.notFoundHandler } } }
get event(): FetchEventLike { if (this.#executionCtx && 'respondWith' in this.#executionCtx) { return this.#executionCtx } else { throw Error('This context has no FetchEvent') } }
get executionCtx(): ExecutionContext { if (this.#executionCtx) { return this.#executionCtx as ExecutionContext } else { throw Error('This context has no ExecutionContext') } }
get res(): Response { this.#isFresh = false return (this.#res ||= new Response('404 Not Found', { status: 404 })) }
set res(_res: Response | undefined) { this.#isFresh = false if (this.#res && _res) { this.#res.headers.delete('content-type') this.#res.headers.forEach((v, k) => { _res.headers.set(k, v) }) } this.#res = _res this.finalized = true }
// eslint-disable-next-line @typescript-eslint/ban-ts-comment // @ts-ignore // eslint-disable-next-line @typescript-eslint/no-explicit-any render: Renderer = (...args: any[]) => this.renderer(...args)
setRenderer = (renderer: Renderer) => { this.renderer = renderer }
header = (name: string, value: string | undefined, options?: { append?: boolean }): void => { // Clear the header if (value === undefined) { if (this.#headers) { this.#headers.delete(name) } else if (this.#preparedHeaders) { delete this.#preparedHeaders[name.toLocaleLowerCase()] } if (this.finalized) { this.res.headers.delete(name) } return }
if (options?.append) { if (!this.#headers) { this.#isFresh = false this.#headers = new Headers(this.#preparedHeaders) this.#preparedHeaders = {} } this.#headers.append(name, value) } else { if (this.#headers) { this.#headers.set(name, value) } else { this.#preparedHeaders ??= {} this.#preparedHeaders[name.toLowerCase()] = value } }
if (this.finalized) { if (options?.append) { this.res.headers.append(name, value) } else { this.res.headers.set(name, value) } } }
status = (status: StatusCode): void => { this.#isFresh = false this.#status = status }
set: Set<E> = (key: string, value: unknown) => { this._var ??= {} this._var[key as string] = value }
get: Get<E> = (key: string) => { return this._var ? this._var[key] : undefined }
// c.var.propName is a read-only get var(): Readonly<E['Variables'] & ContextVariableMap> { return { ...this._var } as never }
newResponse: NewResponse = ( data: Data | null, arg?: StatusCode | ResponseInit, headers?: HeaderRecord ): Response => { // Optimized if (this.#isFresh && !headers && !arg && this.#status === 200) { return new Response(data, { headers: this.#preparedHeaders, }) }
if (arg && typeof arg !== 'number') { this.res = new Response(data, arg) }
const status = typeof arg === 'number' ? arg : arg ? arg.status : this.#status this.#preparedHeaders ??= {}
this.#headers ??= new Headers() for (const [k, v] of Object.entries(this.#preparedHeaders)) { this.#headers.set(k, v) }
if (this.#res) { this.#res.headers.forEach((v, k) => { this.#headers?.set(k, v) }) for (const [k, v] of Object.entries(this.#preparedHeaders)) { this.#headers.set(k, v) } }
headers ??= {} for (const [k, v] of Object.entries(headers)) { if (typeof v === 'string') { this.#headers.set(k, v) } else { this.#headers.delete(k) for (const v2 of v) { this.#headers.append(k, v2) } } }
return new Response(data, { status, headers: this.#headers, }) }
body: BodyRespond = ( data: Data | null, arg?: StatusCode | ResponseInit, headers?: HeaderRecord ): Response => { return typeof arg === 'number' ? this.newResponse(data, arg, headers) : this.newResponse(data, arg) }
text: TextRespond = ( text: string, arg?: StatusCode | ResponseInit, headers?: HeaderRecord ): Response => { // If the header is empty, return Response immediately. // Content-Type will be added automatically as `text/plain`. if (!this.#preparedHeaders) { if (this.#isFresh && !headers && !arg) { return new Response(text) } this.#preparedHeaders = {} } this.#preparedHeaders['content-type'] = TEXT_PLAIN return typeof arg === 'number' ? this.newResponse(text, arg, headers) : this.newResponse(text, arg) }
json: JSONRespond = <T>( object: InterfaceToType<T> extends JSONValue ? T : JSONValue, arg?: StatusCode | ResponseInit, headers?: HeaderRecord ): Response & TypedResponse< InterfaceToType<T> extends JSONValue ? JSONValue extends InterfaceToType<T> ? never : JSONParsed<T> : never > => { const body = JSON.stringify(object) this.#preparedHeaders ??= {} this.#preparedHeaders['content-type'] = 'application/json; charset=UTF-8' /* eslint-disable @typescript-eslint/no-explicit-any */ return ( typeof arg === 'number' ? this.newResponse(body, arg, headers) : this.newResponse(body, arg) ) as any }
/** * @deprecated * `c.jsonT()` will be removed in v4. * Use `c.json()` instead of `c.jsonT()`. * `c.json()` now returns data type, so you can just replace `c.jsonT()` to `c.json()`. */ jsonT: JSONRespond = <T>( object: InterfaceToType<T> extends JSONValue ? T : JSONValue, arg?: StatusCode | ResponseInit, headers?: HeaderRecord ): Response & TypedResponse< InterfaceToType<T> extends JSONValue ? JSONValue extends InterfaceToType<T> ? never : T : never > => { // eslint-disable-next-line @typescript-eslint/no-explicit-any return this.json(object, arg as any, headers) as any }
html: HTMLRespond = ( html: string | Promise<string>, arg?: StatusCode | ResponseInit, headers?: HeaderRecord ): Response | Promise<Response> => { this.#preparedHeaders ??= {} this.#preparedHeaders['content-type'] = 'text/html; charset=UTF-8'
if (typeof html === 'object') { if (!(html instanceof Promise)) { html = (html as string).toString() // HtmlEscapedString object to string } if ((html as string | Promise<string>) instanceof Promise) { return (html as unknown as Promise<string>) .then((html) => resolveStream(html)) .then((html) => { return typeof arg === 'number' ? this.newResponse(html, arg, headers) : this.newResponse(html, arg) }) } }
return typeof arg === 'number' ? this.newResponse(html as string, arg, headers) : this.newResponse(html as string, arg) }
redirect = (location: string, status: StatusCode = 302): Response => { this.#headers ??= new Headers() this.#headers.set('Location', location) return this.newResponse(null, status) }
streamText = ( cb: (stream: StreamingApi) => Promise<void>, arg?: StatusCode | ResponseInit, headers?: HeaderRecord ): Response => { headers ??= {} this.header('content-type', TEXT_PLAIN) this.header('x-content-type-options', 'nosniff') this.header('transfer-encoding', 'chunked') return this.stream(cb, arg, headers) }
stream = ( cb: (stream: StreamingApi) => Promise<void>, arg?: StatusCode | ResponseInit, headers?: HeaderRecord ): Response => { const { readable, writable } = new TransformStream() const stream = new StreamingApi(writable) cb(stream).finally(() => stream.close())
return typeof arg === 'number' ? this.newResponse(readable, arg, headers) : this.newResponse(readable, arg) }
/** @deprecated * Use Cookie Middleware instead of `c.cookie()`. The `c.cookie()` will be removed in v4. * * @example * * import { setCookie } from 'hono/cookie' * // ... * app.get('/', (c) => { * setCookie(c, 'key', 'value') * //... * }) */ cookie = (name: string, value: string, opt?: CookieOptions): void => { const cookie = serialize(name, value, opt) this.header('set-cookie', cookie, { append: true }) }
notFound = (): Response | Promise<Response> => { // eslint-disable-next-line @typescript-eslint/ban-ts-comment // @ts-ignore return this.notFoundHandler(this) }
/** @deprecated * Use `getRuntimeKey()` exported from `hono/adapter` instead of `c.runtime()`. The `c.runtime()` will be removed in v4. * * @example * * import { getRuntimeKey } from 'hono/adapter' * // ... * app.get('/', (c) => { * const key = getRuntimeKey() * //... * }) */ get runtime(): Runtime { // eslint-disable-next-line @typescript-eslint/no-explicit-any const global = globalThis as any
if (global?.Deno !== undefined) { return 'deno' }
if (global?.Bun !== undefined) { return 'bun' }
if (typeof global?.WebSocketPair === 'function') { return 'workerd' }
if (typeof global?.EdgeRuntime === 'string') { return 'edge-light' }
if (global?.fastly !== undefined) { return 'fastly' }
if (global?.__lagon__ !== undefined) { return 'lagon' }
if (global?.process?.release?.name === 'node') { return 'node' }
return 'other' }}