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src/functions/compose.ts

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+import { Transform, Writable, Pipe, WritableOptions } from "stream";
+
+class Compose extends Writable implements Pipe {
+    private head: Writable | Transform;
+    private tail: Writable | Transform;
+    constructor(
+        streams: Array<Transform | Writable>,
+        options?: WritableOptions,
+    ) {
+        super(options);
+        if (streams.length < 2) {
+            throw new Error("Cannot compose 1 or less streams");
+        }
+        this.head = streams[0];
+        for (let i = 1; i < streams.length; i++) {
+            streams[i - 1].pipe(streams[i]);
+        }
+        this.tail = streams[streams.length - 1];
+    }
+
+    public pipe<T extends NodeJS.WritableStream>(
+        destination: T,
+        options: { end?: boolean } | undefined,
+    ) {
+        return this.tail.pipe(
+            destination,
+            options,
+        );
+    }
+
+    public _write(chunk: any, enc: string, cb: any) {
+        this.head.write(chunk.toString ? chunk.toString() : chunk, cb);
+    }
+}
+
+/**
+ * Return a Readable stream of readable streams concatenated together
+ * @param streams Readable streams to concatenate
+ */
+export function compose(
+    streams: Array<Transform | Writable>,
+    options?: WritableOptions,
+): Compose {
+    return new Compose(streams, options);
+}