Vacuum not handling YAML anchors correctly

[TristanSpeakEasy]

Consider the two attached OpenAPI docs. One is a yaml document with anchors and the other is the same document that I have just inlined the anchors by doing a roundtrip through https://github.com/go-yaml/yaml

The below reproducible code shows that the document with anchors returns incorrect yaml nodes when present (specifically I am getting a node with no content).

package main

import (
	"fmt"
	"log"
	"os"

	"github.com/daveshanley/vacuum/model"
	"github.com/daveshanley/vacuum/motor"
	"github.com/daveshanley/vacuum/rulesets"
	"github.com/pb33f/libopenapi"
	"github.com/pb33f/libopenapi/datamodel"
	libopenapiUtils "github.com/pb33f/libopenapi/utils"
	"gopkg.in/yaml.v3"
)

type testRule struct{}

func (r *testRule) GetSchema() model.RuleFunctionSchema {
	return model.RuleFunctionSchema{
		Name: "test",
	}
}

func (r *testRule) RunRule(nodes []*yaml.Node,
	context model.RuleFunctionContext,
) []model.RuleFunctionResult {
	results := []model.RuleFunctionResult{}

	for _, schema := range context.Index.GetAllSchemas() {
		for _, nodeType := range []string{"anyOf", "allOf", "oneOf"} {
			keyNode, valNode := libopenapiUtils.FindKeyNode(nodeType, schema.Node.Content)
			if valNode == nil {
				continue
			}

			if len(valNode.Content) == 0 {
				results = append(results, model.RuleFunctionResult{
					Message:      "empty keyword found",
					Path:         schema.Path + "." + nodeType,
					RuleId:       context.Rule.Id,
					StartNode:    keyNode,
					EndNode:      valNode,
					RuleSeverity: context.Rule.Severity,
				})
			}
		}
	}

	return results
}

func (r *testRule) GetCategory() string {
	return "validation"
}

func main() {
	docConf := &datamodel.DocumentConfiguration{
		AllowRemoteReferences:               true,
		AllowFileReferences:                 true,
		IgnorePolymorphicCircularReferences: true,
		IgnoreArrayCircularReferences:       true,
		ExtractRefsSequentially:             true,
	}

	// data, err := os.ReadFile("openapi.yaml")
	data, err := os.ReadFile("openapi-inlined.yaml")
	if err != nil {
		log.Fatalf("error: %v", err)
	}

	d, err := libopenapi.NewDocumentWithConfiguration(data, docConf)
	if err != nil {
		log.Fatalf("error: %v", err)
	}

	ex := &motor.RuleSetExecution{
		RuleSet: &rulesets.RuleSet{
			Rules: map[string]*model.Rule{
				"test": {
					Name:         "test",
					Id:           "test",
					Given:        "$",
					Resolved:     false,
					Severity:     "error",
					Formats:      model.OAS3AllFormat,
					RuleCategory: model.RuleCategories[model.CategoryValidation],
					Type:         rulesets.Validation,
					Then: model.RuleAction{
						Function: "test",
					},
				},
			},
		},
		Document: d,
		PanicFunction: func(err any) {
			log.Fatalf("error: %v", err)
		},
		CustomFunctions: map[string]model.RuleFunction{
			"test": &testRule{},
		},
		AllowLookup: true,
	}

	results := motor.ApplyRulesToRuleSet(ex)

	for _, result := range results.Results {
		log.Printf("result: %v", result)
	}

	if len(results.Results) > 0 {
		log.Fatalf("errors found")
	}

	fmt.Println("done")
}

The code returns errors found in the version with anchors and just returns done in the inlined version

openapi.zip

[Jakousa]

This bug makes vacuum unusable for any real world use cases. Here's another example:

Given file:

openapi: 3.0.3

x-a: &anchor
  important-field: true

x-b:
  <<: *anchor

and rule set

rules:
  test-rule:
    description: Important field must be defined on all levels
    message: "important-field must be defined"
    severity: error
    given: $.x-b
    then:
      field: important-field
      function: defined

Spectral works as expected

$ spectral lint config.yaml --ruleset ruleset.yaml
No results with a severity of 'error' found!

Vacuum does not:

$ vacuum -r ruleset.yaml lint config.yaml -d
Location                           | Severity | Message                         | Rule      | Category   | Path
config.yaml:7:3                    | error    | important-field must be defined | test-rule | Validation | $.x-b

          Linting file 'config.yaml' failed with 1 errors, 0 warnings and 0 informs