UnhandledPromiseRejectionWarning: TypeError: Cannot create property 'parameters' on string 'Description'

[sergebesson]

Describe the bug
expressOpenapiValidator.middleware generates an error UnhandledPromiseRejectionWarning

To Reproduce
Here is an example that systematically reproduces the bug from version 4.3.1 to version 4.4.0 of ʻexpress-openapi-validator`.
The bug does not occur in version 4.3.0

const expressOpenapiValidator = require("express-openapi-validator");
const apiSpec = {
  "openapi": "3.0.0",
  "info": { "title": "Api test", "version": "1.0.0" },
  "servers": [{ "url": "/api" }],
  "paths": {
    "/test/{id}": {
      "description": "Description",
      "parameters": [{ "name": "id", "in": "path", "required": true, "schema": { "type": "string" }}],
      "get": {
        "responses": {
          "200": {
            "description": "response",
            "content": {
              "application/json": {
                "schema": {
                  "type": "object",
                  "properties": { "id": { "type": "string" }, "label": { "type": "string" }}
                }
              }
            }
          }
        }
      }
    }
  }
};

expressOpenapiValidator.middleware({
  apiSpec: apiSpec,
  validateRequests: true,
  validateResponses: true,
});

Here is the result when we run this small example with ʻexpress-openapi-validator` in version 4.4.0

node test.js 
(node:25275) UnhandledPromiseRejectionWarning: TypeError: Cannot create property 'parameters' on string 'Description'
    at RequestSchemaPreprocessor.preprocessPathLevelParameters (/DISKS/sdb1/serge-1604/tmp/test/node_modules/express-openapi-validator/dist/middlewares/parsers/request.schema.preprocessor.js:47:22)
    at paths.forEach (/DISKS/sdb1/serge-1604/tmp/test/node_modules/express-openapi-validator/dist/middlewares/parsers/request.schema.preprocessor.js:19:22)
    at Array.forEach (<anonymous>)
    at RequestSchemaPreprocessor.preProcess (/DISKS/sdb1/serge-1604/tmp/test/node_modules/express-openapi-validator/dist/middlewares/parsers/request.schema.preprocessor.js:12:15)
    at spec.then (/DISKS/sdb1/serge-1604/tmp/test/node_modules/express-openapi-validator/dist/openapi.validator.js:86:16)
    at process._tickCallback (internal/process/next_tick.js:68:7)
    at Function.Module.runMain (internal/modules/cjs/loader.js:832:11)
    at startup (internal/bootstrap/node.js:283:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)
(node:25275) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:25275) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

node version : v10.16.0

[cdimascio]

@sergebesson thanks for the issue. this is fixed in 4v.4.1

[sergebesson]

Thanks for the fix :-)