Optional parameter on endpoint level is categorised as breaking change

[mencnert]

When parameter is added as required: false I would expect it to be non breaking change.

version: github.com/pb33f/libopenapi v0.22.3

code sample:

package main

import (
	"fmt"
	"testing"

	"github.com/pb33f/libopenapi"
)

func TestBreakingChanges(t *testing.T) {

	prev := []byte(`openapi: 3.0.3
paths:
  test:
    get: {}
    parameters:
      - in: query
        name: test
        required: true 
        schema:
          type: string
`)

	curr := []byte(`openapi: 3.0.3
paths:
  test:
    get: {}
    parameters:
      - in: query
        name: test
        required: true
        schema:
          type: string
      - in: query
        name: test2
        required: false
        schema:
          type: string
`)

	prevDoc, err := libopenapi.NewDocument(prev)

	if err != nil {
		panic(fmt.Sprintf("cannot create prev document: %e", err))
	}

	currDoc, err := libopenapi.NewDocument(curr)

	if err != nil {
		panic(fmt.Sprintf("cannot create curr document: %e", err))
	}

	documentChanges, errs := libopenapi.CompareDocuments(prevDoc, currDoc)

	if len(errs) > 0 {
		for i := range errs {
			fmt.Printf("error: %e\n", errs[i])
		}
		panic(fmt.Sprintf("cannot compare documents: %d errors reported", len(errs)))
	}

	if documentChanges.TotalBreakingChanges() > 0 {
		t.Errorf("expected no breaking changes, but found %d", documentChanges.TotalBreakingChanges())
	}
}

[obechny]

Same here; the optional query parameter is evaluated as a breaking change.

[milan-vondra]

Yes, I encountered the same issue recently, very annoying.

[daveshanley]

The fix has been approved, it will make it into the next release, which has a number of changes going in.