Make ApiError::code optional

RUST_LOG=trace,hyper=warn cargo test -- --ignored api::v2::clock::tests::request_clock_with_invalid_credentials --nocapture

src/client.rs

@@ -376,7 +376,7 @@ mod tests {
     match err {
       RequestError::Endpoint(GetNotFoundError::UnexpectedStatus(status, message)) => {
         let expected = ApiError {
-          code: 40410000,
+          code: Some(40410000),
           message: "endpoint not found".to_string(),
         };
         assert_eq!(message, Ok(expected));

src/data/v2/bars.rs

@@ -434,7 +434,11 @@ mod tests {
     let err = client.issue::<Get>(&request).await.unwrap_err();
     match err {
       // 42210000 is the error code reported for "invalid symbol".
-      RequestError::Endpoint(GetError::InvalidInput(Ok(message))) if message.code == 42210000 => (),
+      RequestError::Endpoint(GetError::InvalidInput(Ok(message)))
+        if message.code == Some(42210000) =>
+      {
+        ()
+      },
       _ => panic!("Received unexpected error: {err:?}"),
     };
   }

src/data/v2/quotes.rs

@@ -172,7 +172,11 @@ mod tests {
     let err = client.issue::<Get>(&request).await.unwrap_err();
     match err {
       // 42210000 is the error code reported for "invalid symbol".
-      RequestError::Endpoint(GetError::InvalidInput(Ok(message))) if message.code == 42210000 => (),
+      RequestError::Endpoint(GetError::InvalidInput(Ok(message)))
+        if message.code == Some(42210000) =>
+      {
+        ()
+      },
       _ => panic!("Received unexpected error: {err:?}"),
     };
   }

src/data/v2/trades.rs

@@ -297,7 +297,11 @@ mod tests {
     let err = client.issue::<Get>(&request).await.unwrap_err();
     match err {
       // 42210000 is the error code reported for "invalid symbol".
-      RequestError::Endpoint(GetError::InvalidInput(Ok(message))) if message.code == 42210000 => (),
+      RequestError::Endpoint(GetError::InvalidInput(Ok(message)))
+        if message.code == Some(42210000) =>
+      {
+        ()
+      },
       _ => panic!("Received unexpected error: {err:?}"),
     };
   }

src/endpoint.rs

@@ -19,17 +19,24 @@ pub enum ConversionError {
   UrlEncode(#[from] UrlEncodeError),
 }
 
+fn format_code(code: &Option<u64>) -> String {
+  if let Some(code) = code {
+    format!(" ({code})")
+  } else {
+    String::new()
+  }
+}
 
 /// An error as reported by API endpoints.
 // Note that actually this type should probably be specific to the API
 // version in question. However, at this point we only support v2, so we
 // luck out here.
 #[derive(Clone, Debug, Deserialize, Error, Eq, PartialEq)]
-#[error("{message} ({code})")]
+#[error("{message}{}", format_code(.code))]
 pub struct ApiError {
   /// An error code as provided by Alpaca.
   #[serde(rename = "code")]
-  pub code: u64,
+  pub code: Option<u64>,
   /// A message as provided by Alpaca.
   #[serde(rename = "message")]
   pub message: String,