@nestjs/graphql/dist/decorators/subscription.decorator.js

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

import { SetMetadata } from '@nestjs/common';
import { isString } from '@nestjs/common/utils/shared.utils.js';
import 'reflect-metadata';
import { Resolver } from '../enums/resolver.enum.js';
import { SUBSCRIPTION_OPTIONS_METADATA } from '../graphql.constants.js';
import { UndefinedReturnTypeError } from '../schema-builder/errors/undefined-return-type.error.js';
import { LazyMetadataStorage } from '../schema-builder/storages/lazy-metadata.storage.js';
import { TypeMetadataStorage } from '../schema-builder/storages/type-metadata.storage.js';
import { reflectTypeFromMetadata } from '../utils/reflection.utilts.js';
import { addResolverMetadata } from './resolvers.utils.js';
/**
 * Subscription handler (method) Decorator. Routes subscriptions to this method.
 *
 * @publicApi
 */
export function Subscription(nameOrType, options = {}) {
    return (target, key, descriptor) => {
        const name = isString(nameOrType)
            ? nameOrType
            : (options && options.name) || undefined;
        addResolverMetadata(Resolver.SUBSCRIPTION, name, target, key, descriptor);
        SetMetadata(SUBSCRIPTION_OPTIONS_METADATA, options)(target, key, descriptor);
        LazyMetadataStorage.store(target.constructor, () => {
            if (!nameOrType || isString(nameOrType)) {
                throw new UndefinedReturnTypeError(Subscription.name, key);
            }
            const { typeFn, options: typeOptions } = reflectTypeFromMetadata({
                metadataKey: 'design:returntype',
                prototype: target,
                propertyKey: key,
                explicitTypeFn: nameOrType,
                typeOptions: options,
            });
            const metadata = {
                methodName: key,
                schemaName: options.name || key,
                target: target.constructor,
                typeFn,
                returnTypeOptions: typeOptions,
                description: options.description,
                deprecationReason: options.deprecationReason,
            };
            TypeMetadataStorage.addSubscriptionMetadata(metadata);
        });
    };
}