package main

import (
	"context"

	"gocloud.dev/blob"

	_ "gocloud.dev/blob/gcsblob"
)

func main() {
	ctx := context.Background()
	bucket, err := blob.OpenBucket(ctx, "gs://my-bucket")
	if err != nil {
		panic(err)
	}

	exists, err := bucket.Exists(ctx, "valid.tar.gz")
	if err != nil {
		panic(err)
	}
	if !exists {
		panic("the file should have existed")
	}

	exists, err = bucket.Exists(ctx, "invalid.tar.gz")
	if err != nil {
		panic(err)
	}
	if exists {
		panic("the file should not have existed")
	}
}