OpenAPI: parses the 'validate' struct tag

examples/full-app-gourmet/controller/ingredient.go

@@ -28,7 +28,7 @@ func (rs ingredientRessource) getAllIngredients(c fuego.ContextNoBody) ([]store.
 }
 
 type CreateIngredient struct {
-	Name        string `json:"name" validate:"required,min=3,max=20"`
+	Name        string `json:"name" validate:"required,min=3,max=20" example:"Tomato"`
 	Description string `json:"description"`
 }
 

openapi3/openapi3.go

@@ -100,9 +100,14 @@ type Schema struct {
 	Type       string            `json:"type,omitempty" yaml:"type"`
 	Format     string            `json:"format,omitempty" yaml:"format,omitempty"`
 	Required   []string          `json:"required,omitempty" yaml:"required,omitempty"`
+	Nullable   bool              `json:"nullable,omitempty" yaml:"nullable,omitempty"`
 	Example    string            `json:"example,omitempty" yaml:"example,omitempty"`
 	Properties map[string]Schema `json:"properties,omitempty" yaml:"properties,omitempty"`
 	Items      *Schema           `json:"items,omitempty" yaml:"items,omitempty"`
+	MinLength  int               `json:"minLength,omitempty" yaml:"minLength,omitempty"`
+	MaxLength  int               `json:"maxLength,omitempty" yaml:"maxLength,omitempty"`
+	Minimum    int               `json:"minimum,omitempty" yaml:"minimum,omitempty"`
+	Maximum    int               `json:"maximum,omitempty" yaml:"maximum,omitempty"`
 	Ref        string            `json:"$ref,omitempty" yaml:"$ref,omitempty"`
 }
 

openapi3/parse_validate.go

@@ -0,0 +1,29 @@
+package openapi3
+
+import (
+	"strconv"
+	"strings"
+)
+
+// parses the "validate" tag used by go-playground/validator and sets the schema accordingly
+func parseValidate(s *Schema, tag string) {
+	for _, item := range strings.Split(tag, ",") {
+		if strings.Contains(item, "min=") {
+			min := strings.Split(item, "min=")[1]
+			if s.Type == "integer" || s.Type == "number" {
+				s.Minimum, _ = strconv.Atoi(min)
+			} else if s.Type == "string" {
+				s.MinLength, _ = strconv.Atoi(min)
+			}
+		}
+
+		if strings.Contains(item, "max=") {
+			max := strings.Split(item, "max=")[1]
+			if s.Type == "integer" || s.Type == "number" {
+				s.Maximum, _ = strconv.Atoi(max)
+			} else if s.Type == "string" {
+				s.MaxLength, _ = strconv.Atoi(max)
+			}
+		}
+	}
+}

openapi3/parse_validate_test.go

@@ -0,0 +1,62 @@
+package openapi3
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseValidate(t *testing.T) {
+	t.Run("empty", func(t *testing.T) {
+		s := &Schema{}
+		parseValidate(s, "")
+	})
+
+	t.Run("required", func(t *testing.T) {
+		t.Skip("TODO")
+		s := &Schema{}
+		parseValidate(s, "required")
+		require.Equal(t, true, s.Required)
+	})
+
+	t.Run("min for int", func(t *testing.T) {
+		s := &Schema{
+			Type: "integer",
+		}
+		parseValidate(s, "min=10")
+		require.Equal(t, 10, s.Minimum)
+	})
+
+	t.Run("max for int", func(t *testing.T) {
+		s := &Schema{
+			Type: "integer",
+		}
+		parseValidate(s, "max=10")
+		require.Equal(t, 10, s.Maximum)
+	})
+
+	t.Run("min for string", func(t *testing.T) {
+		s := &Schema{
+			Type: "string",
+		}
+		parseValidate(s, "min=10")
+		require.Equal(t, 10, s.MinLength)
+	})
+
+	t.Run("max for string", func(t *testing.T) {
+		s := &Schema{
+			Type: "string",
+		}
+		parseValidate(s, "max=10")
+		require.Equal(t, 10, s.MaxLength)
+	})
+
+	t.Run("multiple", func(t *testing.T) {
+		s := &Schema{
+			Type: "string",
+		}
+		parseValidate(s, "required,min=10,max=20")
+		require.Equal(t, 10, s.MinLength)
+		require.Equal(t, 20, s.MaxLength)
+	})
+}

openapi3/to_schema.go

@@ -72,11 +72,15 @@ func ToSchema(v any) *Schema {
 				if strings.Contains(fieldType.Tag.Get("validate"), "required") {
 					s.Required = append(s.Required, fieldName)
 				}
-				s.Properties[fieldName] = Schema{
+
+				fieldSchema := Schema{
 					Type:    fieldTypeType,
 					Example: fieldType.Tag.Get("example"),
 					Format:  format,
 				}
+				parseValidate(&fieldSchema, fieldType.Tag.Get("validate"))
+				s.Properties[fieldName] = fieldSchema
+
 			}
 		}
 	}