bitwarden-browser/src/services/browserMessaging.service.ts

import {
    MessagingService,
    PlatformUtilsService,
} from 'jslib/abstractions';

export default class BrowserMessagingService implements MessagingService {
    constructor(private platformUtilsService: PlatformUtilsService) {
    }

    send(subscriber: string, arg: any = {}) {
        // if safari, else
        const message = Object.assign({}, { command: subscriber }, arg);
        chrome.runtime.sendMessage(message);
    }
}