@mountainpass/hooked-cli/dist/lib/common/CaptureStream.js

A tool for runnable scripts

import { Writable } from "stream";
// A class that captures output while also passing it through to the original stream
export class CaptureStream extends Writable {
    constructor(originalStream, options) {
        super(options);
        this.originalStream = originalStream;
        this.captureBuffer = '';
        this.finished = false;
        // Listen for the finish event
        this.on('finish', () => {
            this.finished = true;
            this.whenFinished(this.captureBuffer);
        });
    }
    whenUpdated(captured) {
        // NOOP used for testing
    }
    whenFinished(captured) {
        // NOOP used for testing
    }
    _write(chunk, encoding, callback) {
        // Convert the chunk to a string
        const chunkStr = chunk.toString();
        // Capture the chunk
        this.captureBuffer += chunkStr;
        this.whenUpdated(this.captureBuffer);
        // Pass the chunk through to the original stream
        if (this.originalStream) {
            this.originalStream.write(chunkStr);
        }
        // Call the callback to signal that writing is complete
        callback();
    }
    getCaptured() {
        return this.captureBuffer;
    }
}