@kronos-integration/service-http/src/ctx-body-param-interceptor.mjs

http server

import { CTXInterceptor } from "./ctx-interceptor.mjs";
import { APPLICATION_JSON, TEXT_PLAIN } from "./constants.mjs";

const _typeDecoders = {
  "application/x-www-form-urlencoded": async ctx => {
    const chunks = [];
    for await (const chunk of ctx.req) {
      chunks.push(chunk);
    }

    return Object.fromEntries(new URLSearchParams(chunks.join("")).entries());
  },
  "application/json": async ctx => {
    const chunks = [];
    for await (const chunk of ctx.req) {
      chunks.push(chunk);
    }
    return JSON.parse(chunks.join(""));
  }
};

/**
 * Extracts params from request body.
 * Supported content types are:
 * - application/json
 * - application/x-www-form-urlencoded
 */
export class CTXBodyParamInterceptor extends CTXInterceptor {
  /**
   * @return {string} 'ctx-body-param'
   */
  static get name() {
    return "ctx-body-param";
  }

  typeDecoders = _typeDecoders;

  async receive(endpoint, next, ctx, ...args) {
    for (const [type, decoder] of Object.entries(this.typeDecoders)) {
      if (ctx.is(type)) {
        const response = await next(await decoder(ctx), ...args);

        if (typeof response === "string") {
          ctx.res.writeHead(200, {
            ...this.headers,
            ...TEXT_PLAIN
          });
          ctx.res.end(response);
        } else {
          ctx.res.writeHead(200, {
            ...this.headers,
            ...APPLICATION_JSON
          });
          ctx.res.end(JSON.stringify(response));
        }
        return;
      }
    }

    ctx.throw(
      415,
      `Unsupported content type ${ctx.req.headers["content-type"]} [${Object.keys(this.typeDecoders)}]`
    );
  }
}