megalodon/lib/esm/parser.js

Fediverse API client for node.js and browser

import { EventEmitter } from 'events';
export class Parser extends EventEmitter {
    message;
    constructor() {
        super();
        this.message = '';
    }
    parse(chunk) {
        if (chunk === ':thump\n') {
            this.emit('heartbeat', {});
            return;
        }
        this.message += chunk;
        chunk = this.message;
        const size = chunk.length;
        let start = 0;
        let offset = 0;
        let curr;
        let next;
        while (offset < size) {
            curr = chunk[offset];
            next = chunk[offset + 1];
            if (curr === '\n' && next === '\n') {
                const piece = chunk.slice(start, offset);
                offset += 2;
                start = offset;
                if (!piece.length)
                    continue;
                const root = piece.split('\n');
                if (root.length !== 2)
                    continue;
                const event = root[0].substr(7);
                const data = root[1].substr(6);
                let jsonObj = {};
                try {
                    jsonObj = JSON.parse(data);
                }
                catch (err) {
                    if (event !== 'delete') {
                        this.emit('error', new Error(`Error parsing API reply: '${piece}', error message: '${err}'`));
                        continue;
                    }
                }
                switch (event) {
                    case 'update':
                        this.emit('update', jsonObj);
                        break;
                    case 'notification':
                        this.emit('notification', jsonObj);
                        break;
                    case 'conversation':
                        this.emit('conversation', jsonObj);
                        break;
                    case 'delete':
                        this.emit('delete', data);
                        break;
                    default:
                        this.emit('error', new Error(`Unknown event has received: ${event}`));
                        continue;
                }
            }
            offset++;
        }
        this.message = chunk.slice(start, size);
    }
}