type is modified when float64 has zero value

[Evilolipop]

package main

import (
	"fmt"

	"github.com/dop251/goja"
)

var (
	value float64
	i     interface{}
)

func main() {
	value = 0
	i = value
	vm := goja.New()
	o := vm.NewObject()
	o.Set("a", i)
	fmt.Printf("o.Get(\"a\").ExportType(): %v\n", o.Get("a").ExportType())
}

And I got o.Get("a").ExportType(): int64

[Dmitry Panov]

Not just zero, any number representable as int64 is converted into int64. If you need to preserve the original type, the only option is to use a custom float64 type.