How to check file `name` (with any extension) does exist in the directory in Golang?

I know I could check the file does exist or not in Golang by the answers of the following questions.

• How to check whether a file or directory denoted by a path exists in Golang?
• How to check if a file exists in Go?
• Gist - Check if file or directory exists in Golang

The code looks like this.

_, err := os.Stat(path)
if err == nil {
    log.Printf("File %s exists.", path)
} else if os.IsNotExist(err) {
    log.Printf("File %s not exists.", path)
} else {
    log.Printf("File %s stat error: %v", path, err)
}

But here's my real question, how do I check the filename does exist (has been used) in the specified directory? For example if I have a file tree like this:

--- uploads
       |- foo.png
       |- bar.mp4

I wanted to check if there's any file is using the specified name..

used := filenameUsed("uploads/foo")
fmt.Println(used) // Output: true

used = filenameUsed("uploads/hello")
fmt.Println(used) // Output: false

How do I implement the filenameUsed function?

Google gave me a path/filepath package as the result but I have no clue about how to use it.