Unmarshal JSON

We can decode JSON bytes (or strings) into a Go struct using json.Unmarshal or a json.Decoder.

The Decode method of json.Decoder streams data from an io.Reader into a Go struct, while json.Unmarshal works with data that's already in []byte format. Using a json.Decoder can be more memory-efficient because it doesn't load all the data into memory at once. json.Unmarshal is ideal for small JSON data you already have in memory. When dealing with HTTP requests and responses, you will likely use json.Decoder since it works directly with an io.Reader.

// res is an http.Response
defer res.Body.Close()

data, err := io.ReadAll(res.Body)
if err != nil {
	return nil, err
}

var issues []Issue
if err := json.Unmarshal(data, &issues); err != nil {
    return nil, err
}