bson.RawValue Marshal/Unmarshal

main.go

package main

import (
	"fmt"

	"go.mongodb.org/mongo-driver/bson"
)

func main() {
	// Create an original exmaple document
	originalDoc, err := bson.Marshal(bson.D{
		{"status", "status1"},
		{"fieldA", 10},
		{"fieldB", 20},
	})
	if err != nil {
		panic(err)
	}
	fmt.Printf("original doc: %s\n\n", bson.Raw(originalDoc))

	// Unmarshal into intermediary type
	var temp map[string]bson.RawValue
	if err = bson.Unmarshal(originalDoc, &temp); err != nil {
		panic(err)
	}

	// Decode individual fields for inspection
	var status string
	if err = temp["status"].Unmarshal(&status); err != nil {
		panic(err)
	}
	fmt.Printf("original status: %s\n\n", status)

	// Change the status based on its original value
	newStatus := fmt.Sprintf("new%s", status)
	newStatusType, newStatusData, err := bson.MarshalValue(newStatus)
	if err != nil {
		panic(err)
	}
	temp["status"] = bson.RawValue{
		Type:  newStatusType,
		Value: newStatusData,
	}

	// Marshal new document and compare
	changedDoc, err := bson.Marshal(temp)
	if err != nil {
		panic(err)
	}
	fmt.Printf("new doc: %s\n", bson.Raw(changedDoc))
}