Default parameter changes are not detected as breaking changes in -check-breaking about oasdiff

[reuvenharrison]

@WillGunn good catch, but the behavior with required=false is the same.
There's a PR in the works to fix this with a new check.

[blva]

Thanks for the quick fix @reuvenharrison!

[reuvenharrison]

From the OpenAPI spec:

Default Parameter Values
Use the default keyword in the parameter schema to specify the default value for an optional parameter. The default value is the one that the server uses if the client does not supply the parameter value in the request.

According to the definition of a breaking-change, a change to the spec that could break a client is considered breaking.

So if a client is relying on a default value X and it changes to Y, this is breaking.

I'll provide a fix.

[WillGunn]

A required field with a default value doesn't make much sense, if you change the schema to be required: false, does the diff tool behave properly @blva ?

[blva]

great point @WillGunn, just updated the specs w/ required:false and got same result from breaking-only which makes sense and is aligned with the OpenAPI specs:

base

openapi: 3.0.1
info:
  title: Test
tags:
- name: Tests
  description: Test tag.
paths:
  /api/changeToDefaultParameterValues/{pathParam}:
    get:
      tags:
      - Tests
      summary: This is a test
      description: Test description.
      operationId: getTest
      parameters:
      - name: queryParam
        in: query
        description: Query param
        required: false
        schema:
          maxLength: 10
          minLength: 1
          type: string
          default: default
      - name: pathParam
        in: path
        description: Query param
        required: false
        schema:
          maxLength: 10
          minLength: 1
          type: string
          default: default
      - name: headerParam
        in: header
        description: Query param
        required: false
        schema:
          maxLength: 10
          minLength: 1
          type: string
          default: default
      requestBody:
        description: Request body
        content:
          application/text:
            schema:
              type: string
        required: false
      responses:
        "200":
          description: OK
          content:
            application/json:
              schema:
                type: string

revision

penapi: 3.0.1
info:
  title: Test
tags:
- name: Tests
  description: Test tag.
paths:
  /api/changeToDefaultParameterValues/{pathParam}:
    get:
      tags:
      - Tests
      summary: This is a test
      description: Test description.
      operationId: getTest
      parameters:
      - name: queryParam
        in: query
        description: Query param
        required: false
        schema:
          maxLength: 10
          minLength: 1
          type: string
          default: newDefault
      - name: pathParam
        in: path
        description: Query param
        required: false
        schema:
          maxLength: 10
          minLength: 1
          type: string
          default: newDefault
      - name: headerParam
        in: header
        description: Query param
        required: false
        schema:
          maxLength: 10
          minLength: 1
          type: string
          default: newDefault
      requestBody:
        description: Request body
        content:
          application/text:
            schema:
              type: string
        required: false
      responses:
        "200":
          description: OK
          content:
            application/json:
              schema:
                type: string

result

paths:
    modified:
        /api/changeToDefaultParameterValues/{pathParam}:
            operations:
                modified:
                    GET:
                        parameters:
                            modified:
                                header:
                                    headerParam:
                                        schema:
                                            default:
                                                from: default
                                                to: newDefault
                                path:
                                    pathParam:
                                        schema:
                                            default:
                                                from: default
                                                to: newDefault
                                query:
                                    queryParam:
                                        schema:
                                            default:
                                                from: default
                                                to: newDefault