clean-up: fix most clippy warnings

src/application_default_credentials.rs

@@ -2,15 +2,11 @@ use crate::error::Error;
 use crate::types::TokenInfo;
 
 /// Provide options for the Application Default Credential Flow, mostly used for testing
+#[derive(Default, Clone, Debug)]
 pub struct ApplicationDefaultCredentialsFlowOpts {
     /// Used as base to build the url during token request from GCP metadata server
     pub metadata_url: Option<String>,
 }
-impl Default for ApplicationDefaultCredentialsFlowOpts {
-    fn default() -> Self {
-        Self { metadata_url: None }
-    }
-}
 
 pub struct ApplicationDefaultCredentialsFlow {
     metadata_url: String,

src/authenticator.rs

@@ -113,7 +113,7 @@ where
             (Some(t), _) if !t.is_expired() && !force_refresh => {
                 // unexpired token found
                 log::debug!("found valid token in cache: {:?}", t);
-                Ok(t.into())
+                Ok(t)
             }
             (
                 Some(TokenInfo {

src/authorized_user.rs

@@ -10,7 +10,7 @@ use hyper::header;
 use serde::{Deserialize, Serialize};
 use url::form_urlencoded;
 
-const TOKEN_URI: &'static str = "https://accounts.google.com/o/oauth2/token";
+const TOKEN_URI: &str = "https://accounts.google.com/o/oauth2/token";
 
 /// JSON schema of authorized user secret. You can obtain it by
 /// running on the client: `gcloud auth application-default login`.

src/device.rs

@@ -82,7 +82,7 @@ impl DeviceFlow {
         loop {
             tokio::time::sleep(interval).await;
             interval = match Self::poll_token(
-                &app_secret,
+                app_secret,
                 hyper_client,
                 &device_auth_resp.device_code,
                 grant_type,

src/service_account.rs

@@ -142,7 +142,7 @@ impl JWTSigner {
     fn sign_claims(&self, claims: &Claims) -> Result<String, rustls::TLSError> {
         let mut jwt_head = Self::encode_claims(claims);
         let signature = self.signer.sign(jwt_head.as_bytes())?;
-        jwt_head.push_str(".");
+        jwt_head.push('.');
         append_base64(&signature, &mut jwt_head);
         Ok(jwt_head)
     }
@@ -152,7 +152,7 @@ impl JWTSigner {
     fn encode_claims(claims: &Claims) -> String {
         let mut head = String::new();
         append_base64(GOOGLE_RS256_HEAD, &mut head);
-        head.push_str(".");
+        head.push('.');
         append_base64(&serde_json::to_string(&claims).unwrap(), &mut head);
         head
     }
@@ -190,7 +190,7 @@ impl ServiceAccountFlow {
         T: AsRef<str>,
         C: hyper::client::connect::Connect + Clone + Send + Sync + 'static,
     {
-        let claims = Claims::new(&self.key, scopes, self.subject.as_ref().map(|x| x.as_str()));
+        let claims = Claims::new(&self.key, scopes, self.subject.as_deref());
         let signed = self.signer.sign_claims(&claims).map_err(|_| {
             Error::LowLevelError(io::Error::new(
                 io::ErrorKind::Other,

src/storage.rs

@@ -343,7 +343,7 @@ impl JSONTokens {
                     hash,
                     filter,
                 };
-                entry.insert(json_token.clone());
+                entry.insert(json_token);
             }
         }
         Ok(())