Openapi3 和 CSV 响应（用于 Dredd）

Question

I test my Api with DREDD against it's specification (written in Openapi3 considering, painfull limitations of Support by Dredd considered ). No I have one endpoint, which produces CSV-data if the Accept-header is set so.

    '/my-endpoint':
        summary: ...
        description: ...
        get:
 #          parameters:
 #              - 
 #                  in: header
 #                  name: Accept
 #                  description: "Response format: application/json or text/csv"
 #                  example: "text/csv"
            responses:
                '200':
                    description: ...
                    content:
                        text/csv:
                            schema:
                                type: string
                            example:
                                summary: 'csv table'
                                value: 'cell1, cell2'

When I run the test with Dredd the test fails with

expected: 
headers: 

body: 
[
  {
    "key": "summary",
    "value": "csv table"
  },
  {
    "key": "value",
    "value": "cell1, cell2"
  }
]
statusCode: 200

Clearly there is something misunderstood and Dredd expects still JSON. Also the API is not told to produce the CSV Version. If I commit in the Accept header in the code abvoe I get the very same result - the expecetd result above and as actual result the JSON version of the my-endpoint-data and also ad warning:

warn: API description parser warning in .../tmp/transformed.specs.yml: 'Parameter Object' 'name' in location 'header' should not be 'Accept', 'Content-Type' or 'Authorization'

I read here and here : Header parameters named Accept, Content-Type and Authorization are not allowed. To describe these headers, use the corresponding OpenAPI keywords Header parameters named Accept, Content-Type and Authorization are not allowed. To describe these headers, use the corresponding OpenAPI keywords - but what are they? According to this and this page it seems to be enough to specify a response of the given type but that is clearly not enough to tell Dredd to produce such a header.

Answer 1

You got an error because the value of the example key is meant to be a literal example value. So in your case it's treated as an object with the summary and value properties.

Change your definition to:

                    content:
                        text/csv:
                            schema:
                                type: string
                            example: 'cell1, cell2'

Or if you want to provide a summary/description for an example, use examples instead:

                    content:
                        text/csv:
                            schema:
                                type: string
                            examples:
                                csv table:
                                    summary: A CSV table with 2 cells
                                    value: 'cell1, cell2'