add RefreshToken method for Authenticator

[JunNishimura]

Overview

Existing code did not have a mechanism to update access tokens with refresh tokens.
So I added RefreshToken method which returns a new access token if it has expired.

Example of use

ctx := context.Background()
token := getToken() // get an existing token somehow
auth := spotifyauth.New()
newToken, err := auth.RefreshToken(ctx, token) // refresh token here
if err != nil {
  fmt.Println(err)
}
if token.AccessToken != newToken.AccessToken {
  saveToken(newToken) // save a new token
}
client := spotify.New(auth.Client(ctx, newToken))

Related

• Error getting current playing song: spotify: couldn't decode error: (46) [User not registered in the Developer Dashboard #232
• refresh token #221

[JunNishimura]

@strideynet
I added RefreshToken method.
I would appreciate it if you check this PR!

[Padi142]

I would love to see this merged. I get a lot of problems with my tokens not refreshing

[JunNishimura]

@Padi142
Unfortunately, this repo has been inactive recently.

If you need the refresh token functionality right now, you can import my forked repo in which I merged this PR.
https://github.com/JunNishimura/spotify

[strideynet]

I'm not sure calling this RefreshToken aligns with the GoDoc comment. Perhaps GetToken would be a clearer name - since the refreshing only occurs in certain circumstances.

[JunNishimura]

@strideynet
Thank you for you opinion, and I understand what you are saying.

One concern I have with naming it GetToken is that new users of this library may mistakenly think that they can get *oauth2.Token just by calling the GetToken function. (In fact, users need to call Authenticator Token method to get the token for the first time.)

What do you think about this?

[strideynet]

I see what you are saying - and agree. Let's move forwards with this.

[strideynet]

I see what you are saying - and agree. Let's move forwards with this.

[Padi142]

<3 <3