Fields of type time.Duration should fail when the input is an integer

[arieltorti]

The duration parser provided by the standard library fails when it's input doesn't include a time unit. As expected, fig also fails in such a case, but it doesn't when the input is not wrapped in quotes because it's interpreted as an integer and not a string.

For example, given:

// config.yaml
timeout: 1

// main.go
package main

import (
	"fmt"
	"log"
	"time"

	"github.com/kkyr/fig"
)

type Config struct {
	Timeout time.Duration `fig:"timeout" validate:"required"`
}

func main() {
	var cfg Config
	if err := fig.Load(&cfg); err != nil {
		log.Fatal(err)
	}

	fmt.Printf("%+v\n", cfg)
}

I would expect it to fail because timeout: 1 doesn't have a time unit, instead the config is parsed without errors and the set value is 1ns.

Maybe this could be fixed by adding a check of Int (and maybe float?) values in StringToTimeDurationHookFunc, although I may be missing some other cases.

[kkyr]

time.Duration is an alias to int64 and represents an elapsed time in nanoseconds, so converting an integer to a time.Duration directly using a typecast, e.g. time.Duration(1000), is a valid use case.

I agree that it's not very intuitive to do so but it's not wrong, therefore I don't think parsing should fail when the input is an integer.