serDes is not working with OpenAPI parameters

Describe the bug When there is described parameter with format in parameters section they are not handled by serDes.

To Reproduce Add format: customOne in requestBody and in parameters and define handler in serDes, only the requestBody will be handled.

Actual behavior Only the requestBody formats are handled by serDes definitions.

Expected behavior All inputs must be handled by serDes definitions.

Examples and context index.js

const OpenApiValidator = require("express-openapi-validator");
const express = require("express");
const http = require("http");

const app = express();

app.use(express.json());
app.use(express.text());
app.use(express.urlencoded({ extended: false }));

app.use(
  OpenApiValidator.middleware({
      apiSpec: "./openapi.yaml",
      unknownFormats: ["customOne"],
      serDes: [
        {
          format: "customOne",
          deserialize: (s) => {
            return { customObjectValue: s };
          },
          serialize: (o) => o.toString(),
        }],
    },
  ),
);

app.post("/test/:param1", function(req, res, next) {
  res.json({
    "req.params.param1": req.params.param1,
    "typeof.req.params.param1": typeof req.params.param1, // fail
    "req.params.param2": req.query.param2,
    "typeof.req.params.param2": typeof req.query.param2, // fail
    "req.params.param3": req.body.param3,
    "typeof.req.params.param3": typeof req.body.param3, // success
  });
});

http.createServer(app).listen(3001);
console.log("http://127.0.0.1:3001/");

openapi.yaml

openapi: "3.0.0"
info:
  version: 1.0.0
  title: api-test-gateway

paths:
  /test/{param1}:
    post:
      description: Test serializations
      parameters:
        - name: param1
          in: path
          required: true
          schema:
            type: string
            format: customOne
        - name: param2
          in: query
          required: true
          schema:
            type: string
            format: customOne
      requestBody:
        content:
          application/json:
            schema:
              type: object
              required:
                - param3
              properties:
                param3:
                  type: string
                  format: customOne
      responses:
        "200":
          description: Successful response
          content:
            application/json:
              schema:
                type: object

[jazzzz]

I found the issue: my parameters are declared under the route, not under the method, like this:

paths:
  /users/{id}:
    parameters:
      - name: id
        in: path
        required: true
        schema:
          type: string
          format: mongo-objectid
          pattern: '^[0-9a-fA-F]{24}$'
    get:

The issue also happens for basic types, so it’s not related to serDes.

[pilerou]

Hi @agavazov and @cdimascio Happy to see serDes feature is used. I try to have a look in the next two weeks.