@nestjs/core/interceptors/interceptors-consumer.js

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

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const shared_utils_1 = require("@nestjs/common/utils/shared.utils");
const rxjs_1 = require("rxjs");
const operators_1 = require("rxjs/operators");
const execution_context_host_1 = require("../helpers/execution-context-host");
class InterceptorsConsumer {
    async intercept(interceptors, args, instance, callback, next) {
        if (shared_utils_1.isEmpty(interceptors)) {
            return next();
        }
        const context = this.createContext(args, instance, callback);
        const start$ = rxjs_1.defer(() => this.transformDeffered(next));
        const nextFn = (i = 0) => async () => {
            if (i >= interceptors.length) {
                return start$;
            }
            const handler = {
                handle: () => rxjs_1.from(nextFn(i + 1)()).pipe(operators_1.mergeAll()),
            };
            return interceptors[i].intercept(context, handler);
        };
        return nextFn()();
    }
    createContext(args, instance, callback) {
        return new execution_context_host_1.ExecutionContextHost(args, instance.constructor, callback);
    }
    transformDeffered(next) {
        return rxjs_1.from(next()).pipe(operators_1.switchMap(res => {
            const isDeffered = res instanceof Promise || res instanceof rxjs_1.Observable;
            return isDeffered ? res : Promise.resolve(res);
        }));
    }
}
exports.InterceptorsConsumer = InterceptorsConsumer;