Issue #44: implement Rust client session values errors and CLI

clients/rust/src/error.rs

@@ -1,13 +1,161 @@
 use thiserror::Error as ThisError;
+use tonic::Code;
+
+use crate::generated::mxaccess_gateway::v1::{MxCommandReply, ProtocolStatusCode};
 
 #[derive(Debug, ThisError)]
 pub enum Error {
     #[error("invalid gateway endpoint `{endpoint}`: {detail}")]
     InvalidEndpoint { endpoint: String, detail: String },
 
+    #[error("invalid argument `{name}`: {detail}")]
+    InvalidArgument { name: String, detail: String },
+
     #[error("gateway transport error: {0}")]
     Transport(#[from] tonic::transport::Error),
 
+    #[error("authentication failed: {message}")]
+    Authentication {
+        message: String,
+        #[source]
+        status: Box<tonic::Status>,
+    },
+
+    #[error("authorization failed: {message}")]
+    Authorization {
+        message: String,
+        #[source]
+        status: Box<tonic::Status>,
+    },
+
+    #[error("gateway call timed out: {message}")]
+    Timeout {
+        message: String,
+        #[source]
+        status: Box<tonic::Status>,
+    },
+
+    #[error("gateway call cancelled: {message}")]
+    Cancelled {
+        message: String,
+        #[source]
+        status: Box<tonic::Status>,
+    },
+
     #[error("gateway status error: {0}")]
-    Status(#[from] tonic::Status),
+    Status(Box<tonic::Status>),
+
+    #[error("gateway command failed: {0}")]
+    Command(#[from] Box<CommandError>),
+}
+
+#[derive(Clone, Debug)]
+pub struct CommandError {
+    reply: MxCommandReply,
+}
+
+impl CommandError {
+    pub fn new(reply: MxCommandReply) -> Self {
+        Self { reply }
+    }
+
+    pub fn reply(&self) -> &MxCommandReply {
+        &self.reply
+    }
+
+    pub fn into_reply(self) -> MxCommandReply {
+        self.reply
+    }
+}
+
+impl std::fmt::Display for CommandError {
+    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let status = self.reply.protocol_status.as_ref();
+        let code = status
+            .and_then(|status| ProtocolStatusCode::try_from(status.code).ok())
+            .unwrap_or(ProtocolStatusCode::Unspecified);
+        let message = status.map(|status| status.message.as_str()).unwrap_or("");
+
+        if message.is_empty() {
+            write!(formatter, "{code:?}")
+        } else {
+            write!(formatter, "{code:?}: {message}")
+        }
+    }
+}
+
+impl std::error::Error for CommandError {}
+
+impl From<tonic::Status> for Error {
+    fn from(status: tonic::Status) -> Self {
+        let message = redact_credentials(status.message());
+        match status.code() {
+            Code::Unauthenticated => Self::Authentication {
+                message,
+                status: Box::new(status),
+            },
+            Code::PermissionDenied => Self::Authorization {
+                message,
+                status: Box::new(status),
+            },
+            Code::DeadlineExceeded => Self::Timeout {
+                message,
+                status: Box::new(status),
+            },
+            Code::Cancelled => Self::Cancelled {
+                message,
+                status: Box::new(status),
+            },
+            _ => Self::Status(Box::new(status)),
+        }
+    }
+}
+
+pub fn ensure_command_success(reply: MxCommandReply) -> Result<MxCommandReply, Error> {
+    let code = reply
+        .protocol_status
+        .as_ref()
+        .and_then(|status| ProtocolStatusCode::try_from(status.code).ok())
+        .unwrap_or(ProtocolStatusCode::Unspecified);
+
+    if code == ProtocolStatusCode::Ok {
+        Ok(reply)
+    } else {
+        Err(Box::new(CommandError::new(reply)).into())
+    }
+}
+
+fn redact_credentials(message: &str) -> String {
+    message
+        .split_whitespace()
+        .map(|part| {
+            if part.starts_with("mxgw_") || part.eq_ignore_ascii_case("bearer") {
+                "<redacted>"
+            } else {
+                part
+            }
+        })
+        .collect::<Vec<_>>()
+        .join(" ")
+}
+
+#[cfg(test)]
+mod tests {
+    use tonic::{Code, Status};
+
+    use super::Error;
+
+    #[test]
+    fn classifies_authentication_status() {
+        let error = Error::from(Status::new(
+            Code::Unauthenticated,
+            "invalid API key mxgw_visible_secret",
+        ));
+
+        let message = error.to_string();
+
+        assert!(matches!(error, Error::Authentication { .. }));
+        assert!(message.contains("<redacted>"));
+        assert!(!message.contains("visible_secret"));
+    }
 }