Added MarshalJSON to high level schema.

When building the doctor and rending APIs, I realized that schemas were not being serialized properly when rendering JSON output, this change fixes that.

datamodel/high/base/schema.go

@@ -4,6 +4,7 @@
 package base
 
 import (
+	"encoding/json"
 	"github.com/pb33f/libopenapi/datamodel/high"
 	lowmodel "github.com/pb33f/libopenapi/datamodel/low"
 	"github.com/pb33f/libopenapi/datamodel/low/base"
@@ -492,6 +493,29 @@ func (s *Schema) MarshalYAML() (interface{}, error) {
 	return nb.Render(), nil
 }
 
+// MarshalJSON will create a ready to render JSON representation of the Schema object.
+func (s *Schema) MarshalJSON() ([]byte, error) {
+	nb := high.NewNodeBuilder(s, s.low)
+
+	// determine index version
+	idx := s.GoLow().Index
+	if idx != nil {
+		if idx.GetConfig().SpecInfo != nil {
+			nb.Version = idx.GetConfig().SpecInfo.VersionNumeric
+		}
+	}
+	// render node
+	node := nb.Render()
+	var renderedJSON map[string]interface{}
+
+	// marshal into struct
+	_ = node.Decode(&renderedJSON)
+
+	// return JSON bytes
+	return json.Marshal(renderedJSON)
+}
+
+// MarshalYAMLInline will render out the Schema pointer as YAML, and all refs will be inlined fully
 func (s *Schema) MarshalYAMLInline() (interface{}, error) {
 	nb := high.NewNodeBuilder(s, s.low)
 	nb.Resolve = true
@@ -504,3 +528,25 @@ func (s *Schema) MarshalYAMLInline() (interface{}, error) {
 	}
 	return nb.Render(), nil
 }
+
+// MarshalJSONInline will render out the Schema pointer as JSON, and all refs will be inlined fully
+func (s *Schema) MarshalJSONInline() ([]byte, error) {
+	nb := high.NewNodeBuilder(s, s.low)
+	nb.Resolve = true
+	// determine index version
+	idx := s.GoLow().Index
+	if idx != nil {
+		if idx.GetConfig().SpecInfo != nil {
+			nb.Version = idx.GetConfig().SpecInfo.VersionNumeric
+		}
+	}
+	// render node
+	node := nb.Render()
+	var renderedJSON map[string]interface{}
+
+	// marshal into struct
+	_ = node.Decode(&renderedJSON)
+
+	// return JSON bytes
+	return json.Marshal(renderedJSON)
+}

datamodel/high/base/schema_test.go

@@ -844,6 +844,82 @@ allOf:
 	assert.Equal(t, testSpec, string(schemaBytes))
 }
 
+func TestNewSchemaProxy_RenderSchema_JSON(t *testing.T) {
+	testSpec := `type: object
+description: something object
+`
+
+	var compNode yaml.Node
+	_ = yaml.Unmarshal([]byte(testSpec), &compNode)
+
+	sp := new(lowbase.SchemaProxy)
+
+	// add a config
+	idxConfig := index.CreateOpenAPIIndexConfig()
+	idxConfig.SpecInfo = &datamodel.SpecInfo{
+		VersionNumeric: 3,
+	}
+	idx := index.NewSpecIndexWithConfig(nil, idxConfig)
+
+	err := sp.Build(context.Background(), nil, compNode.Content[0], idx)
+	assert.NoError(t, err)
+
+	lowproxy := low.NodeReference[*lowbase.SchemaProxy]{
+		Value:     sp,
+		ValueNode: compNode.Content[0],
+	}
+
+	schemaProxy := NewSchemaProxy(&lowproxy)
+	compiled := schemaProxy.Schema()
+
+	assert.Equal(t, schemaProxy, compiled.ParentProxy)
+
+	assert.NotNil(t, compiled)
+	assert.Nil(t, schemaProxy.GetBuildError())
+
+	// now render it out, it should be identical, but in JSON
+	schemaBytes, _ := compiled.MarshalJSON()
+	assert.Equal(t, `{"description":"something object","type":"object"}`, string(schemaBytes))
+}
+
+func TestNewSchemaProxy_RenderSchema_JSONInline(t *testing.T) {
+	testSpec := `type: object
+description: something object
+`
+
+	var compNode yaml.Node
+	_ = yaml.Unmarshal([]byte(testSpec), &compNode)
+
+	sp := new(lowbase.SchemaProxy)
+
+	// add a config
+	idxConfig := index.CreateOpenAPIIndexConfig()
+	idxConfig.SpecInfo = &datamodel.SpecInfo{
+		VersionNumeric: 3,
+	}
+	idx := index.NewSpecIndexWithConfig(nil, idxConfig)
+
+	err := sp.Build(context.Background(), nil, compNode.Content[0], idx)
+	assert.NoError(t, err)
+
+	lowproxy := low.NodeReference[*lowbase.SchemaProxy]{
+		Value:     sp,
+		ValueNode: compNode.Content[0],
+	}
+
+	schemaProxy := NewSchemaProxy(&lowproxy)
+	compiled := schemaProxy.Schema()
+
+	assert.Equal(t, schemaProxy, compiled.ParentProxy)
+
+	assert.NotNil(t, compiled)
+	assert.Nil(t, schemaProxy.GetBuildError())
+
+	// now render it out, it should be identical, but in JSON
+	schemaBytes, _ := compiled.MarshalJSONInline()
+	assert.Equal(t, `{"description":"something object","type":"object"}`, string(schemaBytes))
+}
+
 func TestNewSchemaProxy_RenderSchemaWithMultipleObjectTypes(t *testing.T) {
 	testSpec := `type: object
 description: something object