Prove that rest-layer/schema accepts empty Validators.

main.go

package main

import (
	"context"
	"fmt"
	"os"

	"github.com/rs/rest-layer/schema"
)

var taskSchema = &schema.Schema{
	Fields: schema.Fields{
		"id": schema.IDField,
		"task": {
			Description: "A valid task name",
			Validator:   &schema.String{MinLen: 3},
			Required:    true,
		},
		"priority": {
			Description: "The queue priority of the task, 0 is highest",
			Default:     9,
			Validator: &schema.Integer{
				Boundaries: &schema.Boundaries{Min: 0, Max: 10},
			},
		},
		"parameters": {
			Description: "valid parameters depend on the selected task, and are validated when the task starts",
		},
	},
}

func main() {
	if err := taskSchema.Compile(); err != nil {
		fmt.Println("ERROR:", err.Error())
		os.Exit(1)
	}
	task1 := map[string]interface{}{
		"task":       "factorial",
		"priority":   2,
		"parameters": 5,
	}
	task2 := map[string]interface{}{
		"task":       "sortDict",
		"priority":   2,
		"parameters": map[string]interface{}{"three": 3, "two": 2, "five": 5},
	}
	c1, b1 := taskSchema.Prepare(context.TODO(), task1, nil, false)
	fmt.Println("task 1 base:", b1)
	fmt.Println("task 1 change:", c1)
	vt1, errs := taskSchema.Validate(c1, b1)
	if len(errs) > 0 {
		fmt.Println("ERROR:", "task 1 validate", errs)
		os.Exit(1)
	}
	fmt.Println("Validated task 1:", vt1)

	c2, b2 := taskSchema.Prepare(context.TODO(), task2, nil, false)
	fmt.Println("task 2 base:", b2)
	fmt.Println("task 2 change:", c2)
	vt2, errs := taskSchema.Validate(c2, b2)
	if len(errs) > 0 {
		fmt.Println("ERROR:", "task 2 validate", errs)
		os.Exit(1)
	}
	fmt.Println("Validated task 2:", vt2)
}

Output is:

% go run main.go                                                                                                     :(
task 1 base: map[id:b1kp5ntcsrv25cu5khpg]
task 1 change: map[priority:2 parameters:5 task:factorial]
Validated task 1: map[priority:2 parameters:5 id:b1kp5ntcsrv25cu5khpg task:factorial]
task 2 base: map[id:b1kp5ntcsrv25cu5khq0]
task 2 change: map[task:sortDict priority:2 parameters:map[five:5 three:3 two:2]]
Validated task 2: map[priority:2 parameters:map[three:3 two:2 five:5] id:b1kp5ntcsrv25cu5khq0 task:sortDict]