unmarshal fail. 【curl --request GET \ --url https://api.spotify.com/v1/artists/0TnOYISbd1XYRBk9myaseg】

[kristopher8]

json: cannot unmarshal number 1.1113535E7 into Go struct field Followers.followers.total of type uint

[leonid-ed]

Hi @kristopher8 , looks like this is an issue on Spotify side.

I've created a ticket there – would be great if you also add your comment there to make it more visible for the Spotify team.

[tmstn]

I've created a temporary workaround for this issue by adding custom Unmarshal methods to the structs that have inconsistencies.

// FullArtist (artists.go) 
func (f *FullArtist) UnmarshalJSON(data []byte) error {
    var v struct {
        SimpleArtist
        Popularity float64   `json:"popularity"`
        Genres     []string  `json:"genres"`
        Followers  Followers `json:"followers"`
        Images     []Image   `json:"images"`
    }

    if err := json.Unmarshal(data, &v); err != nil {
        return err
    }

    f.SimpleArtist = v.SimpleArtist
    f.Popularity = int(v.Popularity)
    f.Genres = v.Genres
    f.Followers = v.Followers
    f.Images = v.Images

    return nil
}

// Followers (spotify.go)
func (f *Followers) UnmarshalJSON(data []byte) error {
    var v struct {
        Count    float64 `json:"total"`
        Endpoint string  `json:"href"`
    }

    if err := json.Unmarshal(data, &v); err != nil {
        return err
    }

    f.Count = uint(v.Count)
    f.Endpoint = v.Endpoint

    return nil
}

// Image (spotify.go)
func (i *Image) UnmarshalJSON(data []byte) error {
    var v struct {
        Height float64 `json:"height"`
        Width  float64 `json:"width"`
        URL    string  `json:"url"`
    }

    if err := json.Unmarshal(data, &v); err != nil {
        return err
    }

    i.Height = int(v.Height)
    i.Width = int(v.Width)
    i.URL = v.URL

    return nil
}

This should be compatible with endpoints that return integer values as all json numbers are floats by default

[leonid-ed]

@tmstn I've applied your fix in my fork and it worked! Thanks a lot!

[wernerdweight]

I created a PR with the changes from @tmstn.

[wernerdweight]

The float numbers are now actually also in other fields on track structs (SimpleTrack, FullTrack, at least). A custom numeric type would probably be a better solution than custom unmarshaling in this PR. 🤔

[strideynet]

Thanks folks - apologies for not commenting on this. I've been keeping an eye on it and was hoping Spotify would address this, but in typical Spotify fashion, it looks like we won't be seeing a fix on their side.