@cisstech/nestjs-expand/src/lib/expand.interceptor.js

A NestJS module to build Dynamic Resource Expansion for APIs

"use strict";
// expand.interceptor.ts
Object.defineProperty(exports, "__esModule", { value: true });
exports.ExpandInterceptor = void 0;
const tslib_1 = require("tslib");
const common_1 = require("@nestjs/common");
const expand_1 = require("./expand");
const expand_service_1 = require("./expand.service");
let ExpandInterceptor = class ExpandInterceptor {
    constructor(expandService) {
        this.expandService = expandService;
        this.logger = new common_1.Logger(expand_service_1.ExpandService.name);
    }
    /**
     * Intercepts incoming requests and applies expansion based on metadata.
     * @param context - The execution context.
     * @param next - The next call handler.
     * @returns An observable with the expanded response.
     * @throws Error if there's an issue during the expansion process and the error policy is set to 'throw'.
     */
    intercept(context, next) {
        if (context.getType() !== 'http')
            return next.handle();
        const expandable = Reflect.getMetadata(expand_1.EXPANDABLE_KEY, context.getHandler());
        const selectable = Reflect.getMetadata(expand_1.SELECTABLE_KEY, context.getHandler());
        if (!expandable && !selectable && !this.expandService.config.enableGlobalSelection)
            return next.handle();
        const http = context.switchToHttp();
        const req = http.getRequest();
        const res = http.getResponse();
        const original = res.json;
        res.json = async (body) => {
            if (res.statusCode && res.statusCode >= 400)
                return original.call(res, body);
            try {
                const expanded = await this.expandService.expandAndSelect(req, body, expandable, selectable);
                return original.call(res, expanded);
                // eslint-disable-next-line @typescript-eslint/no-explicit-any
            }
            catch (error) {
                const config = this.expandService.config;
                if (config.enableLogging) {
                    // Use configured log level
                    if (config.logLevel === 'error') {
                        this.logger.error(`Error during expansion: ${error.message}`, error.stack);
                    }
                    else if (config.logLevel === 'warn') {
                        this.logger.warn(`Error during expansion: ${error.message}`);
                    }
                    else if (config.logLevel === 'log') {
                        this.logger.log(`Error during expansion: ${error.message}`);
                    }
                    else if (config.logLevel === 'debug') {
                        this.logger.debug(`Error during expansion: ${error.message}`, error.stack);
                    }
                }
                // If the endpoint-level or default policy is 'throw', we need to bubble up the error
                const errorPolicy = expandable?.errorPolicy || config.errorHandling?.defaultErrorPolicy || 'ignore';
                if (errorPolicy === 'throw') {
                    throw error;
                }
                return original.call(res, body);
            }
        };
        return next.handle();
    }
};
exports.ExpandInterceptor = ExpandInterceptor;
exports.ExpandInterceptor = ExpandInterceptor = tslib_1.__decorate([
    (0, common_1.Injectable)(),
    tslib_1.__metadata("design:paramtypes", [expand_service_1.ExpandService])
], ExpandInterceptor);
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