make getting expiration better

Author: Emilgardis

CHANGELOG.md

@@ -19,6 +19,7 @@
 * Made scope take `Cow<&'static str>`
 * Made fields `access_token` and `refresh_token` `pub` on `UserToken`
 * Fixed wrong scope `user:read:stream_key` -> `channel:read:stream_key`
+* BREAKING: changed `TwitchToken::expires` -> `TwitchToken::expires_in` to calculate current lifetime of token
 
 ## End of Changelog 
 

src/lib.rs

@@ -164,7 +164,7 @@ pub async fn refresh_token<RE, C, F>(
 ) -> Result<
     (
         AccessToken,
-        Option<std::time::Instant>,
+        Option<std::time::Duration>,
         Option<RefreshToken>,
     ),
     RefreshTokenError<RE>,
@@ -174,8 +174,6 @@ where
     C: FnOnce(HttpRequest) -> F,
     F: Future<Output = Result<HttpResponse, RE>>,
 {
-    let now = std::time::Instant::now();
-
     let client = TwitchClient::new(
         client_id.clone(),
         Some(client_secret.clone()),
@@ -190,7 +188,7 @@ where
         .await
         .map_err(RefreshTokenError::RequestError)?;
     let refresh_token = res.refresh_token().cloned();
-    let expires = res.expires_in().map(|dur| now + dur);
+    let expires = res.expires_in();
     let access_token = res.access_token;
     Ok((access_token, expires, refresh_token))
 }

src/tokens.rs

@@ -34,8 +34,8 @@ pub trait TwitchToken {
         RE: std::error::Error + Send + Sync + 'static,
         C: FnOnce(HttpRequest) -> F,
         F: Future<Output = Result<HttpResponse, RE>>;
-    /// Get instant when token will expire.
-    fn expires(&self) -> Option<std::time::Instant>;
+    /// Get current lifetime of token.
+    fn expires_in(&self) -> Option<std::time::Duration>;
     /// Retrieve scopes attached to the token
     fn scopes(&self) -> Option<&[Scope]>;
     /// Validate this token. Should be checked on regularly, according to <https://dev.twitch.tv/docs/authentication#validating-requests>
@@ -81,7 +81,7 @@ impl<T: TwitchToken> TwitchToken for Box<T> {
         (**self).refresh_token(http_client).await
     }
 
-    fn expires(&self) -> Option<std::time::Instant> { (**self).expires() }
+    fn expires_in(&self) -> Option<std::time::Duration> { (**self).expires_in() }
 
     fn scopes(&self) -> Option<&[Scope]> { (**self).scopes() }
 }
@@ -99,4 +99,14 @@ pub struct ValidatedToken {
     pub user_id: Option<String>,
     /// Scopes attached to the token.
     pub scopes: Option<Vec<Scope>>,
+    /// Lifetime of the token
+    #[serde(deserialize_with = "seconds_to_duration")]
+    pub expires_in: Option<std::time::Duration>,
+}
+
+fn seconds_to_duration<'a, D: serde::de::Deserializer<'a>>(
+    d: D,
+) -> Result<Option<std::time::Duration>, D::Error> {
+    let seconds = Option::<u64>::deserialize(d)?;
+    Ok(seconds.map(std::time::Duration::from_secs))
 }

src/tokens/app_access_token.rs

@@ -10,9 +10,14 @@ use std::future::Future;
 /// An App Access Token from the [OAuth client credentials flow](https://dev.twitch.tv/docs/authentication/getting-tokens-oauth#oauth-client-credentials-flow)
 #[derive(Debug, Clone)]
 pub struct AppAccessToken {
-    access_token: AccessToken,
-    refresh_token: Option<RefreshToken>,
-    expires: Option<std::time::Instant>,
+    /// The access token used to authenticate requests with
+    pub access_token: AccessToken,
+    /// The refresh token used to extend the life of this user token
+    pub refresh_token: Option<RefreshToken>,
+    /// Expiration from when the response was generated.
+    expires_in: Option<std::time::Duration>,
+    /// When this struct was created, not when token was created.
+    struct_created: std::time::Instant,
     client_id: ClientId,
     client_secret: ClientSecret,
     login: Option<String>,
@@ -36,19 +41,22 @@ impl TwitchToken for AppAccessToken {
         C: FnOnce(HttpRequest) -> F,
         F: Future<Output = Result<HttpResponse, RE>>,
     {
-        let (access_token, expires, refresh_token) = if let Some(token) = self.refresh_token.take()
+        let (access_token, expires_in, refresh_token) = if let Some(token) =
+            self.refresh_token.take()
         {
             crate::refresh_token(http_client, token, &self.client_id, &self.client_secret).await?
         } else {
             return Err(RefreshTokenError::NoRefreshToken);
         };
         self.access_token = access_token;
-        self.expires = expires;
+        self.expires_in = expires_in;
         self.refresh_token = refresh_token;
         Ok(())
     }
 
-    fn expires(&self) -> Option<std::time::Instant> { self.expires }
+    fn expires_in(&self) -> Option<std::time::Duration> {
+        self.expires_in.map(|e| e - self.struct_created.elapsed())
+    }
 
     fn scopes(&self) -> Option<&[Scope]> { self.scopes.as_deref() }
 }
@@ -68,7 +76,8 @@ impl AppAccessToken {
             client_id: client_id.into(),
             client_secret: client_secret.into(),
             login,
-            expires: None,
+            expires_in: None,
+            struct_created: std::time::Instant::now(),
             scopes,
         }
     }
@@ -107,7 +116,6 @@ impl AppAccessToken {
         C: Fn(HttpRequest) -> F,
         F: Future<Output = Result<HttpResponse, RE>>,
     {
-        let now = std::time::Instant::now();
         let client = TwitchClient::new(
             client_id.clone(),
             Some(client_secret.clone()),
@@ -128,7 +136,8 @@ impl AppAccessToken {
         let app_access = AppAccessToken {
             access_token: response.access_token().clone(),
             refresh_token: response.refresh_token().cloned(),
-            expires: response.expires_in().map(|dur| now + dur),
+            expires_in: response.expires_in(),
+            struct_created: std::time::Instant::now(),
             client_id,
             client_secret,
             login: None,

src/tokens/user_token.rs

@@ -21,7 +21,10 @@ pub struct UserToken {
     login: Option<String>,
     /// The refresh token used to extend the life of this user token
     pub refresh_token: Option<RefreshToken>,
-    expires: Option<std::time::Instant>,
+    /// Expiration from when the response was generated.
+    expires_in: Option<std::time::Duration>,
+    /// When this struct was created, not when token was created.
+    struct_created: std::time::Instant,
     scopes: Vec<Scope>,
 }
 
@@ -34,14 +37,16 @@ impl UserToken {
         client_secret: impl Into<Option<ClientSecret>>,
         login: Option<String>,
         scopes: Option<Vec<Scope>>,
+        expires_in: Option<std::time::Duration>,
     ) -> UserToken {
         UserToken {
             access_token: access_token.into(),
             client_id: client_id.into(),
             client_secret: client_secret.into(),
             login,
             refresh_token: refresh_token.into(),
-            expires: None,
+            expires_in,
+            struct_created: std::time::Instant::now(),
             scopes: scopes.unwrap_or_else(Vec::new),
         }
     }
@@ -66,6 +71,7 @@ impl UserToken {
             client_secret,
             validated.login,
             validated.scopes,
+            validated.expires_in,
         ))
     }
 
@@ -105,15 +111,17 @@ impl TwitchToken for UserToken {
                 return Err(RefreshTokenError::NoRefreshToken);
             };
             self.access_token = access_token;
-            self.expires = expires;
+            self.expires_in = expires;
             self.refresh_token = refresh_token;
             Ok(())
         } else {
             return Err(RefreshTokenError::NoClientSecretFound);
         }
     }
 
-    fn expires(&self) -> Option<std::time::Instant> { None }
+    fn expires_in(&self) -> Option<std::time::Duration> {
+        self.expires_in.map(|e| e - self.struct_created.elapsed())
+    }
 
     fn scopes(&self) -> Option<&[Scope]> { Some(self.scopes.as_slice()) }
 }