Update code

mcp-server-ssh/node_modules/eventsource/src/EventSource.ts

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+import {createParser, type EventSourceMessage, type EventSourceParser} from 'eventsource-parser'
+
+import {ErrorEvent, flattenError, syntaxError} from './errors.js'
+import type {
+  AddEventListenerOptions,
+  EventListenerOptions,
+  EventListenerOrEventListenerObject,
+  EventSourceEventMap,
+  EventSourceFetchInit,
+  EventSourceInit,
+  FetchLike,
+  FetchLikeResponse,
+} from './types.js'
+
+/**
+ * An `EventSource` instance opens a persistent connection to an HTTP server, which sends events
+ * in `text/event-stream` format. The connection remains open until closed by calling `.close()`.
+ *
+ * @public
+ * @example
+ * ```js
+ * const eventSource = new EventSource('https://example.com/stream')
+ * eventSource.addEventListener('error', (error) => {
+ *   console.error(error)
+ * })
+ * eventSource.addEventListener('message', (event) => {
+ *  console.log('Received message:', event.data)
+ * })
+ * ```
+ */
+export class EventSource extends EventTarget {
+  /**
+   * ReadyState representing an EventSource currently trying to connect
+   *
+   * @public
+   */
+  static CONNECTING = 0 as const
+
+  /**
+   * ReadyState representing an EventSource connection that is open (eg connected)
+   *
+   * @public
+   */
+  static OPEN = 1 as const
+
+  /**
+   * ReadyState representing an EventSource connection that is closed (eg disconnected)
+   *
+   * @public
+   */
+  static CLOSED = 2 as const
+
+  /**
+   * ReadyState representing an EventSource currently trying to connect
+   *
+   * @public
+   */
+  readonly CONNECTING = 0 as const
+
+  /**
+   * ReadyState representing an EventSource connection that is open (eg connected)
+   *
+   * @public
+   */
+  readonly OPEN = 1 as const
+
+  /**
+   * ReadyState representing an EventSource connection that is closed (eg disconnected)
+   *
+   * @public
+   */
+  readonly CLOSED = 2 as const
+
+  /**
+   * Returns the state of this EventSource object's connection. It can have the values described below.
+   *
+   * [MDN Reference](https://developer.mozilla.org/docs/Web/API/EventSource/readyState)
+   *
+   * Note: typed as `number` instead of `0 | 1 | 2` for compatibility with the `EventSource` interface,
+   * defined in the TypeScript `dom` library.
+   *
+   * @public
+   */
+  public get readyState(): number {
+    return this.#readyState
+  }
+
+  /**
+   * Returns the URL providing the event stream.
+   *
+   * [MDN Reference](https://developer.mozilla.org/docs/Web/API/EventSource/url)
+   *
+   * @public
+   */
+  public get url(): string {
+    return this.#url.href
+  }
+
+  /**
+   * Returns true if the credentials mode for connection requests to the URL providing the event stream is set to "include", and false otherwise.
+   *
+   * [MDN Reference](https://developer.mozilla.org/docs/Web/API/EventSource/withCredentials)
+   */
+  public get withCredentials(): boolean {
+    return this.#withCredentials
+  }
+
+  /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/EventSource/error_event) */
+  public get onerror(): ((ev: ErrorEvent) => unknown) | null {
+    return this.#onError
+  }
+  public set onerror(value: ((ev: ErrorEvent) => unknown) | null) {
+    this.#onError = value
+  }
+
+  /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/EventSource/message_event) */
+  public get onmessage(): ((ev: MessageEvent) => unknown) | null {
+    return this.#onMessage
+  }
+  public set onmessage(value: ((ev: MessageEvent) => unknown) | null) {
+    this.#onMessage = value
+  }
+
+  /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/EventSource/open_event) */
+  public get onopen(): ((ev: Event) => unknown) | null {
+    return this.#onOpen
+  }
+  public set onopen(value: ((ev: Event) => unknown) | null) {
+    this.#onOpen = value
+  }
+
+  override addEventListener<K extends keyof EventSourceEventMap>(
+    type: K,
+    listener: (this: EventSource, ev: EventSourceEventMap[K]) => unknown,
+    options?: boolean | AddEventListenerOptions,
+  ): void
+  override addEventListener(
+    type: string,
+    listener: (this: EventSource, event: MessageEvent) => unknown,
+    options?: boolean | AddEventListenerOptions,
+  ): void
+  override addEventListener(
+    type: string,
+    listener: EventListenerOrEventListenerObject,
+    options?: boolean | AddEventListenerOptions,
+  ): void
+  override addEventListener(
+    type: string,
+    listener:
+      | ((this: EventSource, event: MessageEvent) => unknown)
+      | EventListenerOrEventListenerObject,
+    options?: boolean | AddEventListenerOptions,
+  ): void {
+    const listen = listener as (this: EventSource, event: Event) => unknown
+    super.addEventListener(type, listen, options)
+  }
+
+  override removeEventListener<K extends keyof EventSourceEventMap>(
+    type: K,
+    listener: (this: EventSource, ev: EventSourceEventMap[K]) => unknown,
+    options?: boolean | EventListenerOptions,
+  ): void
+  override removeEventListener(
+    type: string,
+    listener: (this: EventSource, event: MessageEvent) => unknown,
+    options?: boolean | EventListenerOptions,
+  ): void
+  override removeEventListener(
+    type: string,
+    listener: EventListenerOrEventListenerObject,
+    options?: boolean | EventListenerOptions,
+  ): void
+  override removeEventListener(
+    type: string,
+    listener:
+      | ((this: EventSource, event: MessageEvent) => unknown)
+      | EventListenerOrEventListenerObject,
+    options?: boolean | EventListenerOptions,
+  ): void {
+    const listen = listener as (this: EventSource, event: Event) => unknown
+    super.removeEventListener(type, listen, options)
+  }
+
+  constructor(url: string | URL, eventSourceInitDict?: EventSourceInit) {
+    super()
+
+    try {
+      if (url instanceof URL) {
+        this.#url = url
+      } else if (typeof url === 'string') {
+        this.#url = new URL(url, getBaseURL())
+      } else {
+        throw new Error('Invalid URL')
+      }
+    } catch (err) {
+      throw syntaxError('An invalid or illegal string was specified')
+    }
+
+    this.#parser = createParser({
+      onEvent: this.#onEvent,
+      onRetry: this.#onRetryChange,
+    })
+
+    this.#readyState = this.CONNECTING
+    this.#reconnectInterval = 3000
+    this.#fetch = eventSourceInitDict?.fetch ?? globalThis.fetch
+    this.#withCredentials = eventSourceInitDict?.withCredentials ?? false
+
+    this.#connect()
+  }
+
+  /**
+   * Aborts any instances of the fetch algorithm started for this EventSource object, and sets the readyState attribute to CLOSED.
+   *
+   * [MDN Reference](https://developer.mozilla.org/docs/Web/API/EventSource/close)
+   *
+   * @public
+   */
+  close(): void {
+    if (this.#reconnectTimer) clearTimeout(this.#reconnectTimer)
+    if (this.#readyState === this.CLOSED) return
+    if (this.#controller) this.#controller.abort()
+    this.#readyState = this.CLOSED
+    this.#controller = undefined
+  }
+
+  // PRIVATES FOLLOW
+
+  /**
+   * Current connection state
+   *
+   * @internal
+   */
+  #readyState: number
+
+  /**
+   * Original URL used to connect.
+   *
+   * Note that this will stay the same even after a redirect.
+   *
+   * @internal
+   */
+  #url: URL
+
+  /**
+   * The destination URL after a redirect. Is reset on reconnection.
+   *
+   * @internal
+   */
+  #redirectUrl: URL | undefined
+
+  /**
+   * Whether to include credentials in the request
+   *
+   * @internal
+   */
+  #withCredentials: boolean
+
+  /**
+   * The fetch implementation to use
+   *
+   * @internal
+   */
+  #fetch: FetchLike
+
+  /**
+   * The reconnection time in milliseconds
+   *
+   * @internal
+   */
+  #reconnectInterval: number
+
+  /**
+   * Reference to an ongoing reconnect attempt, if any
+   *
+   * @internal
+   */
+  #reconnectTimer: ReturnType<typeof setTimeout> | undefined
+
+  /**
+   * The last event ID seen by the EventSource, which will be sent as `Last-Event-ID` in the
+   * request headers on a reconnection attempt.
+   *
+   * @internal
+   */
+  #lastEventId: string | null = null
+
+  /**
+   * The AbortController instance used to abort the fetch request
+   *
+   * @internal
+   */
+  #controller: AbortController | undefined
+
+  /**
+   * Instance of an EventSource parser (`eventsource-parser` npm module)
+   *
+   * @internal
+   */
+  #parser: EventSourceParser
+
+  /**
+   * Holds the current error handler, attached through `onerror` property directly.
+   * Note that `addEventListener('error', …)` will not be stored here.
+   *
+   * @internal
+   */
+  #onError: ((ev: ErrorEvent) => unknown) | null = null
+
+  /**
+   * Holds the current message handler, attached through `onmessage` property directly.
+   * Note that `addEventListener('message', …)` will not be stored here.
+   *
+   * @internal
+   */
+  #onMessage: ((ev: MessageEvent) => unknown) | null = null
+
+  /**
+   * Holds the current open handler, attached through `onopen` property directly.
+   * Note that `addEventListener('open', …)` will not be stored here.
+   *
+   * @internal
+   */
+  #onOpen: ((ev: Event) => unknown) | null = null
+
+  /**
+   * Connect to the given URL and start receiving events
+   *
+   * @internal
+   */
+  #connect() {
+    this.#readyState = this.CONNECTING
+    this.#controller = new AbortController()
+
+    // Browser tests are failing if we directly call `this.#fetch()`, thus the indirection.
+    const fetch = this.#fetch
+    fetch(this.#url, this.#getRequestOptions())
+      .then(this.#onFetchResponse)
+      .catch(this.#onFetchError)
+  }
+
+  /**
+   * Handles the fetch response
+   *
+   * @param response - The Fetch(ish) response
+   * @internal
+   */
+  #onFetchResponse = async (response: FetchLikeResponse) => {
+    this.#parser.reset()
+
+    const {body, redirected, status, headers} = response
+
+    // [spec] a client can be told to stop reconnecting using the HTTP 204 No Content response code.
+    if (status === 204) {
+      // We still need to emit an error event - this mirrors the browser behavior,
+      // and without it there is no way to tell the user that the connection was closed.
+      this.#failConnection('Server sent HTTP 204, not reconnecting', 204)
+      this.close()
+      return
+    }
+
+    // [spec] …Event stream requests can be redirected using HTTP 301 and 307 redirects as with
+    // [spec] normal HTTP requests.
+    // Spec does not say anything about other redirect codes (302, 308), but this seems an
+    // unintended omission, rather than a feature. Browsers will happily redirect on other 3xxs's.
+    if (redirected) {
+      this.#redirectUrl = new URL(response.url)
+    } else {
+      this.#redirectUrl = undefined
+    }
+
+    // [spec] if res's status is not 200, …, then fail the connection.
+    if (status !== 200) {
+      this.#failConnection(`Non-200 status code (${status})`, status)
+      return
+    }
+
+    // [spec] …or if res's `Content-Type` is not `text/event-stream`, then fail the connection.
+    const contentType = headers.get('content-type') || ''
+    if (!contentType.startsWith('text/event-stream')) {
+      this.#failConnection('Invalid content type, expected "text/event-stream"', status)
+      return
+    }
+
+    // [spec] …if the readyState attribute is set to a value other than CLOSED…
+    if (this.#readyState === this.CLOSED) {
+      return
+    }
+
+    // [spec] …sets the readyState attribute to OPEN and fires an event
+    // [spec] …named open at the EventSource object.
+    this.#readyState = this.OPEN
+
+    const openEvent = new Event('open')
+    this.#onOpen?.(openEvent)
+    this.dispatchEvent(openEvent)
+
+    // Ensure that the response stream is a web stream
+    if (typeof body !== 'object' || !body || !('getReader' in body)) {
+      this.#failConnection('Invalid response body, expected a web ReadableStream', status)
+      this.close() // This should only happen if `fetch` provided is "faulty" - don't reconnect
+      return
+    }
+
+    const decoder = new TextDecoder()
+
+    const reader = body.getReader()
+    let open = true
+
+    do {
+      const {done, value} = await reader.read()
+      if (value) {
+        this.#parser.feed(decoder.decode(value, {stream: !done}))
+      }
+
+      if (!done) {
+        continue
+      }
+
+      open = false
+      this.#parser.reset()
+
+      this.#scheduleReconnect()
+    } while (open)
+  }
+
+  /**
+   * Handles rejected requests for the EventSource endpoint
+   *
+   * @param err - The error from `fetch()`
+   * @internal
+   */
+  #onFetchError = (err: Error & {type?: string}) => {
+    this.#controller = undefined
+
+    // We expect abort errors when the user manually calls `close()` - ignore those
+    if (err.name === 'AbortError' || err.type === 'aborted') {
+      return
+    }
+
+    this.#scheduleReconnect(flattenError(err))
+  }
+
+  /**
+   * Get request options for the `fetch()` request
+   *
+   * @returns The request options
+   * @internal
+   */
+  #getRequestOptions(): EventSourceFetchInit {
+    const lastEvent = this.#lastEventId ? {'Last-Event-ID': this.#lastEventId} : undefined
+
+    const init: EventSourceFetchInit = {
+      // [spec] Let `corsAttributeState` be `Anonymous`…
+      // [spec] …will have their mode set to "cors"…
+      mode: 'cors',
+      redirect: 'follow',
+      headers: {Accept: 'text/event-stream', ...lastEvent},
+      cache: 'no-store',
+      signal: this.#controller?.signal,
+    }
+
+    // Some environments crash if attempting to set `credentials` where it is not supported,
+    // eg on Cloudflare Workers. To avoid this, we only set it in browser-like environments.
+    if ('window' in globalThis) {
+      // [spec] …and their credentials mode set to "same-origin"
+      // [spec] …if the `withCredentials` attribute is `true`, set the credentials mode to "include"…
+      init.credentials = this.withCredentials ? 'include' : 'same-origin'
+    }
+
+    return init
+  }
+
+  /**
+   * Called by EventSourceParser instance when an event has successfully been parsed
+   * and is ready to be processed.
+   *
+   * @param event - The parsed event
+   * @internal
+   */
+  #onEvent = (event: EventSourceMessage) => {
+    if (typeof event.id === 'string') {
+      this.#lastEventId = event.id
+    }
+
+    const messageEvent = new MessageEvent(event.event || 'message', {
+      data: event.data,
+      origin: this.#redirectUrl ? this.#redirectUrl.origin : this.#url.origin,
+      lastEventId: event.id || '',
+    })
+
+    // The `onmessage` property of the EventSource instance only triggers on messages without an
+    // `event` field, or ones that explicitly set `message`.
+    if (this.#onMessage && (!event.event || event.event === 'message')) {
+      this.#onMessage(messageEvent)
+    }
+
+    this.dispatchEvent(messageEvent)
+  }
+
+  /**
+   * Called by EventSourceParser instance when a new reconnection interval is received
+   * from the EventSource endpoint.
+   *
+   * @param value - The new reconnection interval in milliseconds
+   * @internal
+   */
+  #onRetryChange = (value: number) => {
+    this.#reconnectInterval = value
+  }
+
+  /**
+   * Handles the process referred to in the EventSource specification as "failing a connection".
+   *
+   * @param error - The error causing the connection to fail
+   * @param code - The HTTP status code, if available
+   * @internal
+   */
+  #failConnection(message?: string, code?: number) {
+    // [spec] …if the readyState attribute is set to a value other than CLOSED,
+    // [spec] sets the readyState attribute to CLOSED…
+    if (this.#readyState !== this.CLOSED) {
+      this.#readyState = this.CLOSED
+    }
+
+    // [spec] …and fires an event named `error` at the `EventSource` object.
+    // [spec] Once the user agent has failed the connection, it does not attempt to reconnect.
+    // [spec] > Implementations are especially encouraged to report detailed information
+    // [spec] > to their development consoles whenever an error event is fired, since little
+    // [spec] > to no information can be made available in the events themselves.
+    // Printing to console is not very programatically helpful, though, so we emit a custom event.
+    const errorEvent = new ErrorEvent('error', {code, message})
+
+    this.#onError?.(errorEvent)
+    this.dispatchEvent(errorEvent)
+  }
+
+  /**
+   * Schedules a reconnection attempt against the EventSource endpoint.
+   *
+   * @param message - The error causing the connection to fail
+   * @param code - The HTTP status code, if available
+   * @internal
+   */
+  #scheduleReconnect(message?: string, code?: number) {
+    // [spec] If the readyState attribute is set to CLOSED, abort the task.
+    if (this.#readyState === this.CLOSED) {
+      return
+    }
+
+    // [spec] Set the readyState attribute to CONNECTING.
+    this.#readyState = this.CONNECTING
+
+    // [spec] Fire an event named `error` at the EventSource object.
+    const errorEvent = new ErrorEvent('error', {code, message})
+    this.#onError?.(errorEvent)
+    this.dispatchEvent(errorEvent)
+
+    // [spec] Wait a delay equal to the reconnection time of the event source.
+    this.#reconnectTimer = setTimeout(this.#reconnect, this.#reconnectInterval)
+  }
+
+  /**
+   * Reconnects to the EventSource endpoint after a disconnect/failure
+   *
+   * @internal
+   */
+  #reconnect = () => {
+    this.#reconnectTimer = undefined
+
+    // [spec] If the EventSource's readyState attribute is not set to CONNECTING, then return.
+    if (this.#readyState !== this.CONNECTING) {
+      return
+    }
+
+    this.#connect()
+  }
+}
+
+/**
+ * According to spec, when constructing a URL:
+ * > 1. Let baseURL be environment's base URL, if environment is a Document object
+ * > 2. Return the result of applying the URL parser to url, with baseURL.
+ *
+ * Thus we should use `document.baseURI` if available, since it can be set through a base tag.
+ *
+ * @returns The base URL, if available - otherwise `undefined`
+ * @internal
+ */
+function getBaseURL(): string | undefined {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  const doc = 'document' in globalThis ? (globalThis as any).document : undefined
+  return doc && typeof doc === 'object' && 'baseURI' in doc && typeof doc.baseURI === 'string'
+    ? doc.baseURI
+    : undefined
+}