foreign/node/src/wire/stream/ensure-stream.virtual.command.ts

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
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//

import type { ClientProvider } from '../../client/index.js';
import { createStream } from './create-stream.command.js';
import { getStream } from './get-stream.command.js';


/**
 * Creates a virtual command that ensures a stream exists.
 * If the stream does not exist, it will be created.
 *
 * @param c - Client provider function
 * @returns Function that ensures a stream exists by name
 */
export const ensureStream = (c: ClientProvider) =>
  async function ensureStream(streamName: string) {
    const stream = await getStream(c)({ streamId: streamName });
    return stream === null ?
      createStream(c)({ name: streamName }) : stream;
  };