generators: Make sure default value is a possible enum value

pkg/generators/enum.go

@@ -75,6 +75,17 @@ func (et *enumType) ValueStrings() []string {
 	return values
 }
 
+// IsValue returns true if the given value is one of the possible enum
+// values.
+func (et *enumType) IsValid(val string) bool {
+	for _, value := range et.Values {
+		if val == fmt.Sprintf("%q", value.Value) {
+			return true
+		}
+	}
+	return false
+}
+
 // DescriptionLines returns a description of the enum in this format:
 //
 // Possible enum values:

pkg/generators/openapi.go

@@ -585,26 +585,27 @@ func mustEnforceDefault(t *types.Type, omitEmpty bool) (interface{}, error) {
 	}
 }
 
-func (g openAPITypeWriter) generateDefault(comments []string, t *types.Type, omitEmpty bool) error {
+func (g openAPITypeWriter) generateDefault(comments []string, t *types.Type, omitEmpty bool) (*string, error) {
 	t = resolveAliasAndEmbeddedType(t)
 	def, err := defaultFromComments(comments)
 	if err != nil {
-		return err
+		return nil, err
 	}
 	if enforced, err := mustEnforceDefault(t, omitEmpty); err != nil {
-		return err
+		return nil, err
 	} else if enforced != nil {
 		if def == nil {
 			def = enforced
 		} else if !reflect.DeepEqual(def, enforced) {
 			enforcedJson, _ := json.Marshal(enforced)
-			return fmt.Errorf("invalid default value (%#v) for non-pointer/non-omitempty. If specified, must be: %v", def, string(enforcedJson))
+			return nil, fmt.Errorf("invalid default value (%#v) for non-pointer/non-omitempty. If specified, must be: %v", def, string(enforcedJson))
 		}
 	}
 	if def != nil {
-		g.Do("Default: $.$,\n", fmt.Sprintf("%#v", def))
+		val := fmt.Sprintf("%#v", def)
+		return &val, nil
 	}
-	return nil
+	return nil, nil
 }
 
 func (g openAPITypeWriter) generateDescription(CommentLines []string) {
@@ -676,9 +677,16 @@ func (g openAPITypeWriter) generateProperty(m *types.Member, parent *types.Type)
 		return nil
 	}
 	omitEmpty := strings.Contains(reflect.StructTag(m.Tags).Get("json"), "omitempty")
-	if err := g.generateDefault(m.CommentLines, m.Type, omitEmpty); err != nil {
+	def, err := g.generateDefault(m.CommentLines, m.Type, omitEmpty)
+	if err != nil {
 		return fmt.Errorf("failed to generate default in %v: %v: %v", parent, m.Name, err)
 	}
+	if def != nil {
+		g.Do("Default: $.$,\n", *def)
+		if enumType, isEnum := g.enumContext.EnumType(m.Type); isEnum && !enumType.IsValid(*def) {
+			return fmt.Errorf("Default value is not a valid enum value: %v not in %v", *def, enumType.ValueStrings())
+		}
+	}
 	t := resolveAliasAndPtrType(m.Type)
 	// If we can get a openAPI type and format for this type, we consider it to be simple property
 	typeString, format := openapi.OpenAPITypeFormat(t.String())
@@ -762,9 +770,13 @@ func (g openAPITypeWriter) generateMapProperty(t *types.Type) error {
 
 	g.Do("Type: []string{\"object\"},\n", nil)
 	g.Do("AdditionalProperties: &spec.SchemaOrBool{\nAllows: true,\nSchema: &spec.Schema{\nSchemaProps: spec.SchemaProps{\n", nil)
-	if err := g.generateDefault(t.Elem.CommentLines, t.Elem, false); err != nil {
+	def, err := g.generateDefault(t.Elem.CommentLines, t.Elem, false)
+	if err != nil {
 		return err
 	}
+	if def != nil {
+		g.Do("Default: $.$,\n", *def)
+	}
 	typeString, format := openapi.OpenAPITypeFormat(elemType.String())
 	if typeString != "" {
 		g.generateSimpleProperty(typeString, format)
@@ -795,9 +807,13 @@ func (g openAPITypeWriter) generateSliceProperty(t *types.Type) error {
 	elemType := resolveAliasAndPtrType(t.Elem)
 	g.Do("Type: []string{\"array\"},\n", nil)
 	g.Do("Items: &spec.SchemaOrArray{\nSchema: &spec.Schema{\nSchemaProps: spec.SchemaProps{\n", nil)
-	if err := g.generateDefault(t.Elem.CommentLines, t.Elem, false); err != nil {
+	def, err := g.generateDefault(t.Elem.CommentLines, t.Elem, false)
+	if err != nil {
 		return err
 	}
+	if def != nil {
+		g.Do("Default: $.$,\n", *def)
+	}
 	typeString, format := openapi.OpenAPITypeFormat(elemType.String())
 	if typeString != "" {
 		g.generateSimpleProperty(typeString, format)

pkg/generators/openapi_test.go

@@ -1633,8 +1633,8 @@ const EnumB EnumType = "b"
 // +k8s:openapi-gen=x-kubernetes-type-tag:type_test
 type Blah struct {
 	// Value is the value.
-	Value EnumType
-	NoCommentEnum EnumType
+	// +default="b"
+	Value *EnumType
 	// +optional
 	OptionalEnum *EnumType
 }`)
@@ -1655,16 +1655,7 @@ Properties: map[string]spec.Schema{
 "Value": {
 SchemaProps: spec.SchemaProps{
 Description: "Value is the value.\n\nPossible enum values:\n - `+"`"+`\"a\"`+"`"+` is a.\n - `+"`"+`\"b\"`+"`"+` is b.",
-Default: "",
-Type: []string{"string"},
-Format: "",
-Enum: []interface{}{"a", "b"},
-},
-},
-"NoCommentEnum": {
-SchemaProps: spec.SchemaProps{
-Description: "Possible enum values:\n - `+"`"+`\"a\"`+"`"+` is a.\n - `+"`"+`\"b\"`+"`"+` is b.",
-Default: "",
+Default: "b",
 Type: []string{"string"},
 Format: "",
 Enum: []interface{}{"a", "b"},
@@ -1679,7 +1670,7 @@ Enum: []interface{}{"a", "b"},
 },
 },
 },
-Required: []string{"Value","NoCommentEnum"},
+Required: []string{"Value"},
 },
 VendorExtensible: spec.VendorExtensible{
 Extensions: spec.Extensions{

test/integration/testdata/enumtype/enum.go

@@ -18,7 +18,8 @@ const FruitRiceBall FruitType = "onigiri"
 // FruitsBasket is the type that contains the enum type.
 // +k8s:openapi-gen=true
 type FruitsBasket struct {
-	Content FruitType `json:"content"`
+	// +optional
+	Content FruitType `json:"content,omitempty"`
 
 	// +default=0
 	Count int `json:"count"`