chore: address Rust 1.73 clippy lints (#2474)

crates/router/src/connector/checkout.rs

@@ -110,7 +110,7 @@ impl ConnectorCommon for Checkout {
         };
 
         router_env::logger::info!(error_response=?response);
-        let errors_list = response.error_codes.clone().unwrap_or(vec![]);
+        let errors_list = response.error_codes.clone().unwrap_or_default();
         let option_error_code_message = conn_utils::get_error_code_error_message_based_on_priority(
             self.clone(),
             errors_list

crates/router/src/connector/cybersource.rs

@@ -101,7 +101,7 @@ impl ConnectorCommon for Cybersource {
             .response
             .parse_struct("Cybersource ErrorResponse")
             .change_context(errors::ConnectorError::ResponseDeserializationFailed)?;
-        let details = response.details.unwrap_or(vec![]);
+        let details = response.details.unwrap_or_default();
         let connector_reason = details
             .iter()
             .map(|det| format!("{} : {}", det.field, det.reason))

crates/router/src/connector/paypal.rs

@@ -1,5 +1,5 @@
 pub mod transformers;
-use std::fmt::Debug;
+use std::fmt::{Debug, Write};
 
 use base64::Engine;
 use common_utils::ext_traits::ByteSliceExt;
@@ -169,12 +169,26 @@ impl ConnectorCommon for Paypal {
             .parse_struct("Paypal ErrorResponse")
             .change_context(errors::ConnectorError::ResponseDeserializationFailed)?;
 
-        let error_reason = response.details.map(|error_details| {
-            error_details
-                .iter()
-                .map(|error| format!("description - {} ; ", error.description))
-                .collect::<String>()
-        });
+        let error_reason = response
+            .details
+            .map(|error_details| {
+                error_details
+                    .iter()
+                    .try_fold::<_, _, CustomResult<_, errors::ConnectorError>>(
+                        String::new(),
+                        |mut acc, error| {
+                            write!(acc, "description - {} ;", error.description)
+                                .into_report()
+                                .change_context(
+                                    errors::ConnectorError::ResponseDeserializationFailed,
+                                )
+                                .attach_printable("Failed to concatenate error details")
+                                .map(|_| acc)
+                        },
+                    )
+            })
+            .transpose()?;
+
         Ok(ErrorResponse {
             status_code: res.status_code,
             code: response.name,

crates/router/src/connector/paypal/transformers.rs

@@ -1655,7 +1655,7 @@ fn get_headers(
     key: &'static str,
 ) -> CustomResult<String, errors::ConnectorError> {
     let header_value = header
-        .get(key.clone())
+        .get(key)
         .map(|value| value.to_str())
         .ok_or(errors::ConnectorError::MissingRequiredField { field_name: key })?
         .into_report()

crates/router/src/core/payment_methods/cards.rs

@@ -977,9 +977,7 @@ pub async fn list_payment_methods(
                     .0
                     .get(&payment_method_type)
                     .map(|required_fields_hm_for_each_connector| {
-                        required_fields_hm
-                            .entry(payment_method)
-                            .or_insert(HashMap::new());
+                        required_fields_hm.entry(payment_method).or_default();
                         required_fields_hm_for_each_connector
                             .fields
                             .get(&connector_variant)

crates/router/src/core/payments/customers.rs

@@ -121,7 +121,7 @@ pub async fn update_connector_customer_in_customers(
         .and_then(|customer| customer.connector_customer.as_ref())
         .and_then(|connector_customer| connector_customer.as_object())
         .map(ToOwned::to_owned)
-        .unwrap_or(serde_json::Map::new());
+        .unwrap_or_default();
 
     let updated_connector_customer_map =
         connector_customer_id.as_ref().map(|connector_customer_id| {

crates/router/src/core/payments/transformers.rs

@@ -423,7 +423,7 @@ where
                 status_code.to_string(),
             )]
         })
-        .unwrap_or(vec![]);
+        .unwrap_or_default();
     if let Some(payment_confirm_source) = payment_intent.payment_confirm_source {
         headers.push((
             "payment_confirm_source".to_string(),

crates/router/src/core/payouts.rs

@@ -1205,10 +1205,7 @@ pub async fn payout_create_db_entries(
         .set_recurring(req.recurring.unwrap_or(false))
         .set_auto_fulfill(req.auto_fulfill.unwrap_or(false))
         .set_return_url(req.return_url.to_owned())
-        .set_entity_type(
-            req.entity_type
-                .unwrap_or(api_enums::PayoutEntityType::default()),
-        )
+        .set_entity_type(req.entity_type.unwrap_or_default())
         .set_metadata(req.metadata.to_owned())
         .set_created_at(Some(common_utils::date_time::now()))
         .set_last_modified_at(Some(common_utils::date_time::now()))

crates/router/src/services/api.rs

@@ -472,11 +472,9 @@ pub async fn send_request(
                 match request.content_type {
                     Some(ContentType::Json) => client.json(&request.payload),
 
-                    Some(ContentType::FormData) => client.multipart(
-                        request
-                            .form_data
-                            .unwrap_or_else(reqwest::multipart::Form::new),
-                    ),
+                    Some(ContentType::FormData) => {
+                        client.multipart(request.form_data.unwrap_or_default())
+                    }
 
                     // Currently this is not used remove this if not required
                     // If using this then handle the serde_part

crates/router/src/types/transformers.rs

@@ -453,7 +453,6 @@ impl ForeignTryFrom<api_models::webhooks::IncomingWebhookEvent> for storage_enum
 
 impl ForeignFrom<storage::Config> for api_types::Config {
     fn foreign_from(config: storage::Config) -> Self {
-        let config = config;
         Self {
             key: config.key,
             value: config.config,
@@ -472,7 +471,6 @@ impl<'a> ForeignFrom<&'a api_types::ConfigUpdate> for storage::ConfigUpdate {
 
 impl<'a> From<&'a domain::Address> for api_types::Address {
     fn from(address: &domain::Address) -> Self {
-        let address = address;
         Self {
             address: Some(api_types::AddressDetails {
                 city: address.city.clone(),