fix drilling down additionalProperties in the boolean case

.github/workflows/go.yml

@@ -69,6 +69,7 @@ jobs:
         cd openapi3/testdata
         go get -u -v github.com/getkin/kin-openapi
         go test -tags with_embed ./...
+        git --no-pager diff && git checkout -- .
         cd -
       if: matrix.go != '1.14'
     - if: runner.os == 'Linux'

openapi3/issue376_test.go

@@ -1,6 +1,7 @@
 package openapi3
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -40,3 +41,62 @@ info:
 
 	require.Equal(t, "string", doc.Components.Schemas["schema2"].Value.Properties["prop"].Value.Type)
 }
+
+func TestMultijsonTagSerialization(t *testing.T) {
+	spec := []byte(`
+openapi: 3.0.0
+components:
+  schemas:
+    unset:
+      type: number
+    #empty-object:
+    # TODO additionalProperties: {}
+    object:
+      additionalProperties: {type: string}
+    boolean:
+      additionalProperties: false
+paths: {}
+info:
+  title: An API
+  version: 1.2.3.4
+`)
+
+	loader := NewLoader()
+
+	doc, err := loader.LoadFromData(spec)
+	require.NoError(t, err)
+
+	err = doc.Validate(loader.Context)
+	require.NoError(t, err)
+
+	for propName, propSchema := range doc.Components.Schemas {
+		ap := propSchema.Value.AdditionalProperties
+		apa := propSchema.Value.AdditionalPropertiesAllowed
+
+		encoded, err := propSchema.MarshalJSON()
+		require.NoError(t, err)
+		require.Equal(t, string(encoded), map[string]string{
+			"unset": `{"type":"number"}`,
+			// TODO: "empty-object":`{"additionalProperties":{}}`,
+			"object":  `{"additionalProperties":{"type":"string"}}`,
+			"boolean": `{"additionalProperties":false}`,
+		}[propName])
+
+		if propName == "unset" {
+			require.True(t, ap == nil && apa == nil)
+			continue
+		}
+
+		apStr := ""
+		if ap != nil {
+			apStr = fmt.Sprintf("{Ref:%s Value.Type:%v}", (*ap).Ref, (*ap).Value.Type)
+		}
+		apaStr := ""
+		if apa != nil {
+			apaStr = fmt.Sprintf("%v", *apa)
+		}
+
+		require.Truef(t, (ap != nil && apa == nil) || (ap == nil && apa != nil),
+			"%s: isnil(%s) xor isnil(%s)", propName, apaStr, apStr)
+	}
+}

openapi3/loader.go

@@ -351,10 +351,10 @@ func (loader *Loader) resolveComponent(
 func drillIntoField(cursor interface{}, fieldName string) (interface{}, error) {
 	// Special case due to multijson
 	if s, ok := cursor.(*SchemaRef); ok && fieldName == "additionalProperties" {
-		if ap := s.Value.AdditionalProperties; ap != nil {
-			return ap, nil
+		if ap := s.Value.AdditionalPropertiesAllowed; ap != nil {
+			return *ap, nil
 		}
-		return s.Value.AdditionalPropertiesAllowed, nil
+		return s.Value.AdditionalProperties, nil
 	}
 
 	switch val := reflect.Indirect(reflect.ValueOf(cursor)); val.Kind() {

openapi3/schema.go

@@ -109,8 +109,6 @@ type Schema struct {
 	Example      interface{}   `json:"example,omitempty" yaml:"example,omitempty"`
 	ExternalDocs *ExternalDocs `json:"externalDocs,omitempty" yaml:"externalDocs,omitempty"`
 
-	// Object-related, here for struct compactness
-	AdditionalPropertiesAllowed *bool `multijson:"additionalProperties,omitempty" json:"-" yaml:"-"`
 	// Array-related, here for struct compactness
 	UniqueItems bool `json:"uniqueItems,omitempty" yaml:"uniqueItems,omitempty"`
 	// Number-related, here for struct compactness
@@ -141,12 +139,13 @@ type Schema struct {
 	Items    *SchemaRef `json:"items,omitempty" yaml:"items,omitempty"`
 
 	// Object
-	Required             []string       `json:"required,omitempty" yaml:"required,omitempty"`
-	Properties           Schemas        `json:"properties,omitempty" yaml:"properties,omitempty"`
-	MinProps             uint64         `json:"minProperties,omitempty" yaml:"minProperties,omitempty"`
-	MaxProps             *uint64        `json:"maxProperties,omitempty" yaml:"maxProperties,omitempty"`
-	AdditionalProperties *SchemaRef     `multijson:"additionalProperties,omitempty" json:"-" yaml:"-"`
-	Discriminator        *Discriminator `json:"discriminator,omitempty" yaml:"discriminator,omitempty"`
+	Required                    []string       `json:"required,omitempty" yaml:"required,omitempty"`
+	Properties                  Schemas        `json:"properties,omitempty" yaml:"properties,omitempty"`
+	MinProps                    uint64         `json:"minProperties,omitempty" yaml:"minProperties,omitempty"`
+	MaxProps                    *uint64        `json:"maxProperties,omitempty" yaml:"maxProperties,omitempty"`
+	AdditionalPropertiesAllowed *bool          `multijson:"additionalProperties,omitempty" json:"-" yaml:"-"` // In this order...
+	AdditionalProperties        *SchemaRef     `multijson:"additionalProperties,omitempty" json:"-" yaml:"-"` // ...for multijson
+	Discriminator               *Discriminator `json:"discriminator,omitempty" yaml:"discriminator,omitempty"`
 }
 
 var _ jsonpointer.JSONPointable = (*Schema)(nil)