# streamcat

**Repository Path**: mirrors_Financial-Times/streamcat

## Basic Information

- **Project Name**: streamcat
- **Description**: Concatenate ReadStreams and Buffers using Node JS
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-09-24
- **Last Updated**: 2026-07-18

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# streamcat

Concatenate Node JS Streams!

You can concatenate the result of Promises, non async buffers and other
streams allowing you to sequence things into an asynchronous Stream.

## Usage

Example, print the contents of `myfileA` followed by `myfileB`, this is
equivalent to using `cat(1)`: `cat myfileA myfileB`.

```JS
var streamCat = require('streamcat');

streamCat([
	fs.createReadStream('myfileA'),
	fs.createReadStream('myfileB')
]).pipe(process.stdout);
```

### API

#### `streamCat(listOfStreamsBuffersOrPromises)`

`streamCat` will take a list of `ReadStream`s, `Buffer`s, or `Promise`s
returning a `ReadStream` or `Buffer` as its only
argument and returns a `ReadStream` that will stream the concatenation of each
item in the list.

You can mix `Buffer`, `ReadStream`, and `Promise` usage, in this instance, the `String`
`"Some content"` will be streamed between `myfileA` and `myfileB`:

```JS
streamCat([
	fs.createReadStream('myfileA'),
	new Buffer("Some content"),
	fs.createReadStream('myfileB')
]).pipe(process.stdout);
```

Example using `Promise`s that has the same result as the above example, the
value in the `Promise` is resolved asynchronously:

```JS
streamCat([
	fs.createReadStream('myfileA'),
	Promise.resolve(new Buffer("Some content")),
	fs.createReadStream('myfileB')
]).pipe(process.stdout);

```

#### Error Handling

The `streamCat` function can take an optional options object as its second
argument.

##### `errorMapper`

The `errorMapper` option allows you to specify a function that can transform
an error from any of the contatenated streams before emitting the error on the
returned stream.

The `errorMapper` must return an error object.

```JS
{
	errorMapper: function(error) {
		error.message = error.message + ": my custom context";
		return error;
	}
}
```

## License

MIT