populate my throw object with error message in json response

Question

I want to populate my error object {'status': response.status, 'msg': ''} with the error message present in the JSON Response of the API if there is any, otherwise throw the error object without any message. But throw {'status': response.status, 'msg': ''} statement is hit before the json_response promise is evaluated and everytime i get the empty message.

How can I populate the message attribute in my error object?

    return await fetch(url.toString(), {
        method: 'post',
        headers: get_headers(url, request_body),
        body: JSON.stringify(request_body)
    })
        .then((response) => {
            console.log(`API Status: ${response.status} API ${url.toString()}`)

            if (!response.ok) {
                // response.json()
                //     .then(json_response => {
                //         console.log(json_response)
                //         logger.error(json_response)
                //         throw {'status': response.status, 'msg': json_response?.errorMessage?.message}
                //     })
                //     .catch((e)=>{
                //         throw e
                //     })
                throw {'status': response.status, 'msg': ''}
            }

            return response.json()
        })
        .then((json_response) => {
            return json_response

        })
}

Answer 1

But throw {'status': response.status, 'msg': ''} statement is hit before the json_response promise is evaluated and everytime i get the empty message.

Well you can't have both at once! Also you'll need to return the promise with the error response:

.then((response) => {
    console.log(`API Status: ${response.status} API ${url.toString()}`)

    if (!response.ok) {
        return response.json()
//      ^^^^^^
           .then(json_response => {
               console.log(json_response)
               logger.error(json_response)
               throw {'status': response.status, 'msg': json_response?.errorMessage?.message}
           });
    }

    return response.json()
})

Btw, when inspecting a http error response, I would recommend to always check the Content-Type header before parsing it as JSON. Many error responses are still html pages or plain text, even for JSON APIs.