element-web/src/autocomplete/CommandProvider.js

import AutocompleteProvider from './AutocompleteProvider';
import Q from 'q';
import Fuse from 'fuse.js';

const COMMANDS = [
    {
        command: '/me',
        args: '<message>',
        description: 'Displays action'
    },
    {
        command: '/ban',
        args: '<user-id> [reason]',
        description: 'Bans user with given id'
    },
    {
        command: '/deop'
    },
    {
        command: '/encrypt'
    },
    {
        command: '/invite'
    },
    {
        command: '/join',
        args: '<room-alias>',
        description: 'Joins room with given alias'
    },
    {
        command: '/kick',
        args: '<user-id> [reason]',
        description: 'Kicks user with given id'
    },
    {
        command: '/nick',
        args: '<display-name>',
        description: 'Changes your display nickname'
    }
];

let COMMAND_RE = /(^\/\w*)/g;

let instance = null;

export default class CommandProvider extends AutocompleteProvider {
    constructor() {
        super(COMMAND_RE);
        this.fuse = new Fuse(COMMANDS, {
           keys: ['command', 'args', 'description']
        });
    }

    getCompletions(query: string, selection: {start: number, end: number}) {
        let completions = [];
        const command = this.getCurrentCommand(query, selection);
        if(command) {
            completions = this.fuse.search(command[0]).map(result => {
                return {
                    title: result.command,
                    subtitle: result.args,
                    description: result.description
                };
            });
        }
        return Q.when(completions);
    }

    getName() {
        return 'Commands';
    }

    static getInstance(): CommandProvider {
        if(instance == null)
            instance = new CommandProvider();

        return instance;
    }
}