Error starting glued server due to suspect schema error

[schulz3000]

Hi,
I struggled a bit to get fastify running with openapi glue.

If I start the fastify server I get following error:
FST_ERR_SCH_BUILD: Failed building the schema for POST: /MyPath, due error undefined unsupported

I created a minimum repro with the attached swagger file:

• MySwagger.txt (Please rename file after download to MySwagger.yaml. Github is not supporting upload of yaml files.)
• npx github:seriousme/fastify-openapi-glue MySwagger.yaml
• cd generatedProject
• npm install
• npm run start
  -> results in described error

Maybe something is wrong with my swagger file but the online swagger editor mentioned no errors.

Can someone give me a hint what is going wrong here?

[seriousme]

Hi,

I had a look and the error is from fastify, not fastify-openapi-glue.

Putting in a console.log(JSON.stringify(item,null,2)); in just before fastify route registration in generatedProject/node-modules/fastify-openapi-glue/index.js shows the config passed to fastify.

{
  "method": "POST",
  "url": "/MyPath",
  "schema": {
    "summary": "My Test Path",
    "response": {
      "200": {
        "allOf": [
          {
            "allOf": [
              {
                "type": "object",
                "x-abstract": true,
                "properties": {
                  "Identifier": {
                    "type": "string",
                    "description": "Identifier of response",
                    "minLength": 1
                  }
                }
              }
            ]
          },
          {
            "type": "object",
            "required": [
              "myPayload"
            ],
            "properties": {
              "myPayload": {
                "type": "string"
              }
            }
          }
        ]
      }
    }
  },
  "operationId": "MyPath",
  "openapiSource": {
    "summary": "My Test Path",
    "responses": {
      "200": {
        "description": "Success",
        "x-nullable": false,
        "schema": {
          "allOf": [
            {
              "allOf": [
                {
                  "type": "object",
                  "x-abstract": true,
                  "properties": {
                    "Identifier": {
                      "type": "string",
                      "description": "Identifier of response",
                      "minLength": 1
                    }
                  }
                }
              ]
            },
            {
              "type": "object",
              "required": [
                "myPayload"
              ],
              "properties": {
                "myPayload": {
                  "type": "string"
                }
              }
            }
          ]
        }
      }
    }
  }
}

The openapiSource property is ignored by fastify.

This config can easily be fed to a very simple fastify server, e.g. see:
test-fastify.js.txt

As far as I can see the schema is valid JSON schema, but somehow fastify doesn't correctly process it. One thing that might be missing is a body parameter, it could be that fastify requires an input parameter on a POST operation. I checked by changing the method to GET but still got the same schema error :-(

Looking at a minimal doc that satisfies your schema

{
  "myPayload": "ABCDEFGH",
  "Identifier": "ABCDEFGHIJKLMNOPQRSTU"
}

it might be an option to simplify your schema, although I suspect that your original schema is bigger than this.

I'm out of ideas for now, and I would suggest taking the simple fastify server code attached to the fastify project for feedback.

Kind regards,
Hans

[schulz3000]

Thanks for the fast reply. You point me in the right direction.
If I add type: object to the schema node in my yaml it works.

responses:
        '200':
          description: Success
          x-nullable: false
          schema:
            type: object
            allOf:
              - $ref: '#/definitions/MyResponse'
              - type: object
                required:
                - myPayload
                properties:
                  myPayload:
                    type: string