@nestjs/microservices/listener-metadata-explorer.js

Nest - modern, fast, powerful node.js web framework (@microservices)

import { CLIENT_CONFIGURATION_METADATA, CLIENT_METADATA, PATTERN_EXTRAS_METADATA, PATTERN_HANDLER_METADATA, PATTERN_METADATA, TRANSPORT_METADATA, } from './constants.js';
import { PatternHandler } from './enums/pattern-handler.enum.js';
import { isFunction, isUndefined, } from '@nestjs/common/internal';
export class ListenerMetadataExplorer {
    metadataScanner;
    constructor(metadataScanner) {
        this.metadataScanner = metadataScanner;
    }
    explore(instance) {
        const instancePrototype = Object.getPrototypeOf(instance);
        return this.metadataScanner
            .getAllMethodNames(instancePrototype)
            .map(method => this.exploreMethodMetadata(instance, instancePrototype, method))
            .filter(metadata => metadata);
    }
    exploreMethodMetadata(instance, instancePrototype, methodKey) {
        const prototypeCallback = instancePrototype[methodKey];
        const handlerType = Reflect.getMetadata(PATTERN_HANDLER_METADATA, prototypeCallback);
        if (isUndefined(handlerType)) {
            return;
        }
        const patterns = Reflect.getMetadata(PATTERN_METADATA, prototypeCallback);
        const transport = Reflect.getMetadata(TRANSPORT_METADATA, prototypeCallback);
        const extras = Reflect.getMetadata(PATTERN_EXTRAS_METADATA, prototypeCallback);
        const targetCallback = instance[methodKey];
        return {
            methodKey,
            targetCallback,
            patterns,
            transport,
            extras,
            isEventHandler: handlerType === PatternHandler.EVENT,
        };
    }
    *scanForClientHooks(instance) {
        for (const propertyKey in instance) {
            if (isFunction(instance[propertyKey])) {
                continue;
            }
            const property = String(propertyKey);
            const isClient = Reflect.getMetadata(CLIENT_METADATA, instance, property);
            if (isUndefined(isClient)) {
                continue;
            }
            const metadata = Reflect.getMetadata(CLIENT_CONFIGURATION_METADATA, instance, property);
            yield { property, metadata };
        }
    }
}