thrift-gen-validator

thrift-gen-validator

thrift-gen-validator is a thriftgo plugin to generate struct validators.
Users can define validation rule for struct-like(struct/union/exception) in Thrift file, then the generator will generate IsValid() error method for those structs.

for example:

enum MapKey {
    A, B, C, D, E, F
}

struct Example {
    1: string Message (vt.min_size = "30") // length of Message should be greater than or equal to 30
    2: i32 ID (vt.ge = "10000") // ID must be greater than or euqal to 10000
    3: list<double> Values (vt.elem.gt = "0.25") // element of Values must be greater than 0.25
    4: map<MapKey, string> KeyValues (vt.key.defined_only = "true") // value of KeyValues'key must be defined in MapKey
}

generated method:

func (p *Example) IsValid() error {
	if len(p.Message) < int(30) {
		return fmt.Errorf("field Message min_len rule failed, current value: %d", len(p.Message))
	}
	if p.ID < int32(10000) {
		return fmt.Errorf("field ID ge rule failed, current value: %v", p.ID)
	}
	for i := 0; i < len(p.Values); i++ {
		_elem := p.Values[i]
		if _elem <= float64(0.25) {
			return fmt.Errorf("field _elem gt rule failed, current value: %v", _elem)
		}
	}
	for k := range p.KeyValues {
		if k.String() == "<UNSET>" {
			return fmt.Errorf("field k defined_only rule failed")
		}
	}
	return nil
}

Install

go install github.com/cloudwego/thrift-gen-validator

Usage

Thriftgo

thriftgo -g go -p validator my.thrift

Kitex

kitex --thrift-plugin validator -service a.b.c my.thrift

Feature Matrix

prefix vt, short for "validation" Numeric(i8/i16/i32/i64/double):

Bool:

String/Binary:

Bool:

Enum:

Set/List:

Map:

Struct

Special Value:

1. Field Reference. We can use another field as a validation value.
2. Validation Function. We can use those functions to provide extensive validation ability.

Field Reference Example:

struct Example {
    1: string StringFoo (vt.max_size = "$MaxStringSize")
    2: i32 MaxStringSize
}

Validation Function:

struct Example {
    1: string MaxString
    2: list<string> StringList (vt.elem.max_size = "@len($MaxString)")
}

for now, only len function is available.