deno/ext/node/polyfills/internal/streams/end-of-stream.js

// deno-lint-ignore-file
// Copyright 2018-2025 the Deno authors. MIT license.

import process from "node:process";
import { primordials } from "ext:core/mod.js";
import imported1 from "ext:deno_node/internal/errors.ts";
import { kEmptyObject, once } from "ext:deno_node/internal/util.mjs";
import {
  validateAbortSignal,
  validateBoolean,
  validateFunction,
  validateObject,
} from "ext:deno_node/internal/validators.mjs";

import {
  isClosed,
  isNodeStream,
  isReadable,
  isReadableErrored,
  isReadableFinished,
  isReadableNodeStream,
  isReadableStream,
  isWritable,
  isWritableErrored,
  isWritableFinished,
  isWritableNodeStream,
  isWritableStream,
  kIsClosedPromise,
  willEmitClose as _willEmitClose,
} from "ext:deno_node/internal/streams/utils.js";

import * as _mod2 from "ext:deno_node/internal/events/abort_listener.mjs";

const {
  AbortError,
  codes: {
    ERR_INVALID_ARG_TYPE,
    ERR_STREAM_PREMATURE_CLOSE,
  },
} = imported1;

// Ported from https://github.com/mafintosh/end-of-stream with
// permission from the author, Mathias Buus (@mafintosh).

"use strict";

const {
  Promise,
  PromisePrototypeThen,
  SymbolDispose,
} = primordials;

let addAbortListener;

function isRequest(stream) {
  return stream.setHeader && typeof stream.abort === "function";
}

const nop = () => {};

function eos(stream, options, callback) {
  if (arguments.length === 2) {
    callback = options;
    options = kEmptyObject;
  } else if (options == null) {
    options = kEmptyObject;
  } else {
    validateObject(options, "options");
  }
  validateFunction(callback, "callback");
  validateAbortSignal(options.signal, "options.signal");

  callback = once(callback);

  if (isReadableStream(stream) || isWritableStream(stream)) {
    return eosWeb(stream, options, callback);
  }

  if (!isNodeStream(stream)) {
    throw new ERR_INVALID_ARG_TYPE("stream", [
      "ReadableStream",
      "WritableStream",
      "Stream",
    ], stream);
  }

  const readable = options.readable ?? isReadableNodeStream(stream);
  const writable = options.writable ?? isWritableNodeStream(stream);

  const wState = stream._writableState;
  const rState = stream._readableState;

  const onlegacyfinish = () => {
    if (!stream.writable) {
      onfinish();
    }
  };

  // TODO (ronag): Improve soft detection to include core modules and
  // common ecosystem modules that do properly emit 'close' but fail
  // this generic check.
  let willEmitClose = _willEmitClose(stream) &&
    isReadableNodeStream(stream) === readable &&
    isWritableNodeStream(stream) === writable;

  let writableFinished = isWritableFinished(stream, false);
  const onfinish = () => {
    writableFinished = true;
    // Stream should not be destroyed here. If it is that
    // means that user space is doing something differently and
    // we cannot trust willEmitClose.
    if (stream.destroyed) {
      willEmitClose = false;
    }

    if (willEmitClose && (!stream.readable || readable)) {
      return;
    }

    if (!readable || readableFinished) {
      callback.call(stream);
    }
  };

  let readableFinished = isReadableFinished(stream, false);
  const onend = () => {
    readableFinished = true;
    // Stream should not be destroyed here. If it is that
    // means that user space is doing something differently and
    // we cannot trust willEmitClose.
    if (stream.destroyed) {
      willEmitClose = false;
    }

    if (willEmitClose && (!stream.writable || writable)) {
      return;
    }

    if (!writable || writableFinished) {
      callback.call(stream);
    }
  };

  const onerror = (err) => {
    callback.call(stream, err);
  };

  let closed = isClosed(stream);

  const onclose = () => {
    closed = true;

    const errored = isWritableErrored(stream) || isReadableErrored(stream);

    if (errored && typeof errored !== "boolean") {
      return callback.call(stream, errored);
    }

    if (readable && !readableFinished && isReadableNodeStream(stream, true)) {
      if (!isReadableFinished(stream, false)) {
        return callback.call(stream, new ERR_STREAM_PREMATURE_CLOSE());
      }
    }
    if (writable && !writableFinished) {
      if (!isWritableFinished(stream, false)) {
        return callback.call(stream, new ERR_STREAM_PREMATURE_CLOSE());
      }
    }

    callback.call(stream);
  };

  const onclosed = () => {
    closed = true;

    const errored = isWritableErrored(stream) || isReadableErrored(stream);

    if (errored && typeof errored !== "boolean") {
      return callback.call(stream, errored);
    }

    callback.call(stream);
  };

  const onrequest = () => {
    stream.req.on("finish", onfinish);
  };

  if (isRequest(stream)) {
    stream.on("complete", onfinish);
    if (!willEmitClose) {
      stream.on("abort", onclose);
    }
    if (stream.req) {
      onrequest();
    } else {
      stream.on("request", onrequest);
    }
  } else if (writable && !wState) { // legacy streams
    stream.on("end", onlegacyfinish);
    stream.on("close", onlegacyfinish);
  }

  // Not all streams will emit 'close' after 'aborted'.
  if (!willEmitClose && typeof stream.aborted === "boolean") {
    stream.on("aborted", onclose);
  }

  stream.on("end", onend);
  stream.on("finish", onfinish);
  if (options.error !== false) {
    stream.on("error", onerror);
  }
  stream.on("close", onclose);

  if (closed) {
    process.nextTick(onclose);
  } else if (wState?.errorEmitted || rState?.errorEmitted) {
    if (!willEmitClose) {
      process.nextTick(onclosed);
    }
  } else if (
    !readable &&
    (!willEmitClose || isReadable(stream)) &&
    (writableFinished || isWritable(stream) === false) &&
    (wState == null || wState.pendingcb === undefined || wState.pendingcb === 0)
  ) {
    process.nextTick(onclosed);
  } else if (
    !writable &&
    (!willEmitClose || isWritable(stream)) &&
    (readableFinished || isReadable(stream) === false)
  ) {
    process.nextTick(onclosed);
  } else if ((rState && stream.req && stream.aborted)) {
    process.nextTick(onclosed);
  }

  const cleanup = () => {
    callback = nop;
    stream.removeListener("aborted", onclose);
    stream.removeListener("complete", onfinish);
    stream.removeListener("abort", onclose);
    stream.removeListener("request", onrequest);
    if (stream.req) stream.req.removeListener("finish", onfinish);
    stream.removeListener("end", onlegacyfinish);
    stream.removeListener("close", onlegacyfinish);
    stream.removeListener("finish", onfinish);
    stream.removeListener("end", onend);
    stream.removeListener("error", onerror);
    stream.removeListener("close", onclose);
  };

  if (options.signal && !closed) {
    const abort = () => {
      // Keep it because cleanup removes it.
      const endCallback = callback;
      cleanup();
      endCallback.call(
        stream,
        new AbortError(undefined, { cause: options.signal.reason }),
      );
    };
    if (options.signal.aborted) {
      process.nextTick(abort);
    } else {
      addAbortListener ??= _mod2.addAbortListener;
      const disposable = addAbortListener(options.signal, abort);
      const originalCallback = callback;
      callback = once((...args) => {
        disposable[SymbolDispose]();
        originalCallback.apply(stream, args);
      });
    }
  }

  return cleanup;
}

function eosWeb(stream, options, callback) {
  let isAborted = false;
  let abort = nop;
  if (options.signal) {
    abort = () => {
      isAborted = true;
      callback.call(
        stream,
        new AbortError(undefined, { cause: options.signal.reason }),
      );
    };
    if (options.signal.aborted) {
      process.nextTick(abort);
    } else {
      addAbortListener ??= _mod2.addAbortListener;
      const disposable = addAbortListener(options.signal, abort);
      const originalCallback = callback;
      callback = once((...args) => {
        disposable[SymbolDispose]();
        originalCallback.apply(stream, args);
      });
    }
  }
  const resolverFn = (...args) => {
    if (!isAborted) {
      process.nextTick(() => callback.apply(stream, args));
    }
  };
  PromisePrototypeThen(
    stream[kIsClosedPromise].promise,
    resolverFn,
    resolverFn,
  );
  return nop;
}

function finished(stream, opts) {
  let autoCleanup = false;
  if (opts === null) {
    opts = kEmptyObject;
  }
  if (opts?.cleanup) {
    validateBoolean(opts.cleanup, "cleanup");
    autoCleanup = opts.cleanup;
  }
  return new Promise((resolve, reject) => {
    const cleanup = eos(stream, opts, (err) => {
      if (autoCleanup) {
        cleanup();
      }
      if (err) {
        reject(err);
      } else {
        resolve();
      }
    });
  });
}

export { finished };
export default eos;
export { eos };