mediateur/dist/core/mediator.js

A simple library allowing the implementation of the Mediator design pattern

"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
    return new (P || (P = Promise))(function (resolve, reject) {
        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
        step((generator = generator.apply(thisArg, _arguments || [])).next());
    });
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.clear = exports.mediator = void 0;
const multipleHandlers_error_1 = require("./errors/multipleHandlers.error");
const unknownMessage_error_1 = require("./errors/unknownMessage.error");
const middlewares_1 = require("./middlewares");
const registry = new Map();
const metadatas = new Map();
const register = (messageType, messageHandler, metadata = {}) => {
    var _a;
    const handlers = (_a = registry.get(messageType)) !== null && _a !== void 0 ? _a : [];
    registry.set(messageType, [...handlers, messageHandler]);
    const meta = metadatas.get(messageType);
    metadatas.set(messageType, Object.assign(Object.assign({}, meta), metadata));
};
const getHandlers = (messageType) => {
    if (!registry.has(messageType)) {
        throw new unknownMessage_error_1.UnknownMessageError(messageType);
    }
    const handlers = registry.get(messageType);
    return handlers.map((handler) => middlewares_1.middlewares.apply(messageType, handler));
};
const send = (_a) => __awaiter(void 0, [_a], void 0, function* ({ type, data, }) {
    const handlers = getHandlers(type);
    if (handlers.length > 1) {
        throw new multipleHandlers_error_1.MultipleHandlersError(type);
    }
    return handlers[0](data);
});
const publish = (_a) => __awaiter(void 0, [_a], void 0, function* ({ type, data }) {
    const handlers = getHandlers(type);
    yield Promise.all(handlers.map((handler) => handler(data)));
});
const use = (options) => {
    middlewares_1.middlewares.add(options);
};
const getMessageTypes = () => Array.from(registry.keys()).sort();
const getMetadata = (type) => metadatas.get(type);
const getAllMetadata = () => Array.from(metadatas.entries(), ([key, value]) => ({ type: key, metadata: value }));
const mediator = {
    register,
    send,
    publish,
    use,
    getMessageTypes,
    getMetadata,
    getAllMetadata,
};
exports.mediator = mediator;
const clear = () => {
    registry.clear();
    metadatas.clear();
    middlewares_1.middlewares.clear();
};
exports.clear = clear;