JavaScript POST request to Golang server error - Unexpected end of JSON input-CodePudding

I am making a POST request in JavaScript to my Go server to POST some JSON data. The backend recieves the data succesfully.
If I console log the result of the promise I get Unexpected end of JSON input error at line where fetchResponse.json() is called. I cant figure out why it is happening.

JavaScript

const sendScore = async () => {

    try {
        const fetchResponse = await fetch(`http://localhost:8000/sendscore`, {
            method: 'POST',
            headers: {
                'Accept': 'application/json',
                'Content-Type': 'application/json'
            },

            body: JSON.stringify({name:"kris"})
        });

        const data = await fetchResponse.json();
        return data;

    } catch (e) {
        return e;
    }
}

const sendScoreBtn = document.querySelector("#sendScoreBtn");
sendScoreBtn.addEventListener("click", () => {
    console.log("Sending score...")
    const res = sendScore()
    res.then(console.log)

})

Go /sendscore endpoint handler

func recieveScore(w http.ResponseWriter, r *http.Request) {
    var res playerScore
    if err := json.NewDecoder(r.Body).Decode(&res); err != nil {
        fmt.Println("Line 31", err)
    }

    fmt.Println("Res", res)
}

func main() {

    // Serve static files(js, css)
    http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("./static"))))
    http.HandleFunc("/", homePage)
    http.HandleFunc("/sendscore", recieveScore)

    fmt.Println("Server started. Listening on port :8000")
    log.Fatal(http.ListenAndServe(":8000", nil))
}

CodePudding user response：

My problem was not sending response back to the browser and therefore it couldnt parse any JSON. Updated Go handler, which made the process work.

func recieveScore(w http.ResponseWriter, r *http.Request) {
    var res playerScore
    if err := json.NewDecoder(r.Body).Decode(&res); err != nil {
        fmt.Println("Line 31", err)
    }

    fmt.Println("Res", res)
    
    w.Header().Set("Content-Type", "application/json")
    json.NewEncoder(w).Encode(res) // Writing the result to response
}