How do run custom validation functions on embedded structs using go-playground validator

Question

I'm attempting to register custom validation for a struct using go-playgrounds validator package.

The problem I'm having is that the custom validator function I register isn't being called for the embedded struct.

Here is a complete working example: https://play.golang.org/p/r7oaSo890q_L

So, how do I run struct level validations on an embedded struct?

EDIT*

Just to be specific - I don't want to use general struct validation, as I want to have multiple tags for the same type.

What I mean is that using:

validator.RegisterStructValidation(SomeFunc, decimal.Decimal)

won't work for me as I want the flexibility of having multiple tags for the same type. Sometimes I want the decimal to be pos, sometimes neg etc

EDIT2* Here is the code in the link:

package main

import (
    "fmt"
    "github.com/shopspring/decimal"
    "gopkg.in/go-playground/validator.v9"
)


type decimalPosRequest struct {
    MoneyAmount decimal.Decimal `validate:"decimalpos"` // trying to validate this
}

func main() {
    val := validator.New()
    val.RegisterValidation(`decimalpos`,ValidateDecimalPositive)

    request := decimalPosRequest{MoneyAmount: decimal.NewFromFloat(-1.0)}
    err := val.Struct(&request)
    if err == nil {
        fmt.Println("Error! Should have failed but didn't")
    }
}

func ValidateDecimalPositive(fl validator.FieldLevel) bool { // this function is never called for some reason
    // get decimal
    value := fl.Field().Interface().(decimal.Decimal)
    // check is positive
    return value.IsPositive()
}

Answer 1

It looks like validator skip over types that are not registered. We'd have to register the type before registering a custom validation function.

Here's how you could do it: https://go.dev/play/p/o7HrSTGFDxt