use 'thiserror' to derive errors (#20)

* use thiserror to define errors

* simplify error handling

Cargo.toml

@@ -10,6 +10,7 @@ bytes = "1.1.0"
 prost = "0.8.0"
 
 futures-util = { version = "0.3", default-features = false }
+thiserror = "1.0.30"
 
 [dev-dependencies]
 tokio = { version = "1.12.0", features = ["rt-multi-thread", "macros", "time"] }

examples/info.rs

@@ -1,8 +1,8 @@
-use libmavsdk::{info, RequestError, System};
+use libmavsdk::System;
 use std::io::{self, Write};
 
 #[tokio::main]
-async fn main() {
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let args: Vec<String> = std::env::args().skip(1).collect();
 
     if args.len() > 1 {
@@ -14,22 +14,11 @@ async fn main() {
 
     let url = args.get(0).cloned();
 
-    let mut system = match System::connect(url).await {
-        Ok(system) => system,
-        Err(err) => {
-            println!("Connection error: {:?}", err);
-            return;
-        }
-    };
+    let mut system = System::connect(url).await?;
 
-    match system.info.get_version().await {
-        Ok(v) => println!("Version received: {:?}", v),
-        Err(RequestError::MavErr(info::InfoError::Unknown(s))) => {
-            println!("Unknown MAVLink error ({:?})", s);
-        }
-        Err(RequestError::MavErr(info::InfoError::InformationNotReceivedYet(s))) => {
-            println!("{}", s);
-        }
-        Err(RequestError::RpcErr(rpc_err)) => println!("RPC error: {:?}", rpc_err),
-    };
+    let version = system.info.get_version().await?;
+
+    println!("Version received: {:?}", version);
+
+    Ok(())
 }

examples/mocap.rs

@@ -1,9 +1,9 @@
-use libmavsdk::{mocap, RequestError, System};
+use libmavsdk::{mocap, System};
 use std::io::{self, Write};
 use std::time::Duration;
 
 #[tokio::main]
-async fn main() {
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let args: Vec<String> = std::env::args().skip(1).collect();
 
     if args.len() > 1 {
@@ -15,32 +15,17 @@ async fn main() {
 
     let url = args.get(0).cloned();
 
-    let mut system = match System::connect(url).await {
-        Ok(system) => system,
-        Err(err) => {
-            println!("Connection error: {:?}", err);
-            return;
-        }
-    };
+    let mut system = System::connect(url).await?;
 
     let mut vision_position_estimate = mocap::VisionPositionEstimate::default();
     vision_position_estimate.pose_covariance.covariance_matrix = vec![std::f32::NAN];
 
-    let mut counter: i32 = 500;
-
-    while counter > 0 {
-        if let Err(error) = system
+    for _ in 0..500 {
+        system
             .mocap
             .set_vision_position_estimate(vision_position_estimate.clone())
-            .await
-        {
-            match error {
-                RequestError::MavErr(mav_err) => println!("MAVLink error: {:?}", mav_err),
-                RequestError::RpcErr(rpc_err) => println!("RPC error: {:?}", rpc_err.message()),
-            }
-            return;
-        };
-        counter -= 1;
+            .await?;
+
         vision_position_estimate.position_body.x_m += 0.1;
         vision_position_estimate.position_body.y_m -= 0.1;
         vision_position_estimate.position_body.z_m -= 0.01;
@@ -49,4 +34,6 @@ async fn main() {
     }
 
     println!("All sended successfully!");
+
+    Ok(())
 }

examples/telemetry.rs

@@ -3,7 +3,7 @@ use libmavsdk::System;
 use std::io::{self, Write};
 
 #[tokio::main]
-async fn main() {
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let args: Vec<String> = std::env::args().skip(1).collect();
 
     if args.len() > 1 {
@@ -15,23 +15,12 @@ async fn main() {
 
     let url = args.get(0).cloned();
 
-    let mut system = match System::connect(url).await {
-        Ok(system) => system,
-        Err(err) => {
-            println!("Connection error: {:?}", err);
-            return;
-        }
-    };
+    let mut system = System::connect(url).await?;
 
-    let mut stream_odometry = system.telemetry.subscribe_odometry().await.unwrap();
+    let mut stream_odometry = system.telemetry.subscribe_odometry().await?;
     while let Some(odometry) = stream_odometry.next().await {
-        match odometry {
-            Ok(odometry) => println!("Received: {:?}", odometry),
-            Err(err) => {
-                println!("Break: {:?}", err);
-                break;
-            }
-        }
+        println!("Received: {:?}", odometry?);
     }
     println!("Exit");
+    Ok(())
 }

src/generated/info/mod.rs

@@ -1,5 +1,5 @@
 use super::super::FromRpcResponse;
-use super::super::RequestError::{MavErr, RpcErr};
+use super::super::RequestError;
 use super::super::RequestResult;
 use super::super::TonicResult;
 
@@ -45,42 +45,44 @@ impl From<&pb::Version> for Version {
     }
 }
 
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Clone, Debug, thiserror::Error)]
 pub enum InfoError {
+    #[error("Unknown error: {0}")]
     Unknown(String),
+    #[error("Information not yet received: {0}")]
     InformationNotReceivedYet(String),
 }
 
+impl From<InfoError> for RequestError<InfoError> {
+    fn from(e: InfoError) -> Self {
+        Self::Mav(e)
+    }
+}
+
 pub type GetVersionResult = RequestResult<Version, InfoError>;
 
 impl FromRpcResponse<pb::GetVersionResponse> for GetVersionResult {
     fn from_rpc_response(rpc_get_version_response: TonicResult<pb::GetVersionResponse>) -> Self {
-        let get_version_response = rpc_get_version_response.map_err(RpcErr)?.into_inner();
+        let get_version_response = rpc_get_version_response?.into_inner();
 
         let rpc_info_result = get_version_response
             .info_result
-            .ok_or_else(|| MavErr(InfoError::Unknown("InfoResult does not received".into())))?;
+            .ok_or_else(|| InfoError::Unknown("InfoResult does not received".into()))?;
 
-        let info_result =
-            pb::info_result::Result::from_i32(rpc_info_result.result).ok_or_else(|| {
-                MavErr(InfoError::Unknown(
-                    "Unsupported InfoResult.result value".into(),
-                ))
-            })?;
+        let info_result = pb::info_result::Result::from_i32(rpc_info_result.result)
+            .ok_or_else(|| InfoError::Unknown("Unsupported InfoResult.result value".into()))?;
 
         match info_result {
             pb::info_result::Result::Success => match get_version_response.version {
                 Some(ref rpc_version) => Ok(Version::from(rpc_version)),
-                None => Err(MavErr(InfoError::Unknown(
-                    "Version does not received".into(),
-                ))),
+                None => Err(InfoError::Unknown("Version does not received".into()).into()),
             },
             pb::info_result::Result::Unknown => {
-                Err(MavErr(InfoError::Unknown(rpc_info_result.result_str)))
+                Err(InfoError::Unknown(rpc_info_result.result_str).into())
+            }
+            pb::info_result::Result::InformationNotReceivedYet => {
+                Err(InfoError::InformationNotReceivedYet(rpc_info_result.result_str).into())
             }
-            pb::info_result::Result::InformationNotReceivedYet => Err(MavErr(
-                InfoError::InformationNotReceivedYet(rpc_info_result.result_str),
-            )),
         }
     }
 }

src/generated/mocap/mod.rs

@@ -1,5 +1,5 @@
 use super::super::FromRpcResponse;
-use super::super::RequestError::{MavErr, RpcErr};
+use super::super::RequestError;
 use super::super::RequestResult;
 use super::super::TonicResult;
 use std::convert::Into;
@@ -225,18 +225,28 @@ impl Into<pb::Quaternion> for Quaternion {
     }
 }
 
-#[derive(PartialEq, Clone, Debug)]
+#[derive(PartialEq, Clone, Debug, thiserror::Error)]
 pub enum MocapError {
     /// Unknown error
+    #[error("Unknown error: {0}")]
     Unknown(String),
     /// No system is connected
+    #[error("No system is connected: {0}")]
     NoSystem(String),
     /// Connection error
+    #[error("Connection error: {0}")]
     ConnectionError(String),
     /// Invalid request data
+    #[error("Invalid request: {0}")]
     InvalidRequestData(String),
 }
 
+impl From<MocapError> for RequestError<MocapError> {
+    fn from(e: MocapError) -> Self {
+        Self::Mav(e)
+    }
+}
+
 pub type SetVisionPositionEstimateResult = RequestResult<(), MocapError>;
 
 impl FromRpcResponse<pb::SetVisionPositionEstimateResponse> for SetVisionPositionEstimateResult {
@@ -245,33 +255,28 @@ impl FromRpcResponse<pb::SetVisionPositionEstimateResponse> for SetVisionPositio
             pb::SetVisionPositionEstimateResponse,
         >,
     ) -> Self {
-        let rpc_mocap_result = rpc_set_vision_position_estimate_response
-            .map_err(RpcErr)?
+        let rpc_mocap_result = rpc_set_vision_position_estimate_response?
             .into_inner()
             .mocap_result
-            .ok_or_else(|| MavErr(MocapError::Unknown("MocapResult does not received".into())))?;
+            .ok_or_else(|| MocapError::Unknown("MocapResult does not received".into()))?;
 
-        let mocap_result =
-            pb::mocap_result::Result::from_i32(rpc_mocap_result.result).ok_or_else(|| {
-                MavErr(MocapError::Unknown(
-                    "Unsupported MocapResult.result value".into(),
-                ))
-            })?;
+        let mocap_result = pb::mocap_result::Result::from_i32(rpc_mocap_result.result)
+            .ok_or_else(|| MocapError::Unknown("Unsupported MocapResult.result value".into()))?;
 
         match mocap_result {
             pb::mocap_result::Result::Success => Ok(()),
             pb::mocap_result::Result::Unknown => {
-                Err(MavErr(MocapError::Unknown(rpc_mocap_result.result_str)))
+                Err(MocapError::Unknown(rpc_mocap_result.result_str).into())
             }
             pb::mocap_result::Result::NoSystem => {
-                Err(MavErr(MocapError::NoSystem(rpc_mocap_result.result_str)))
+                Err(MocapError::NoSystem(rpc_mocap_result.result_str).into())
+            }
+            pb::mocap_result::Result::ConnectionError => {
+                Err(MocapError::ConnectionError(rpc_mocap_result.result_str).into())
+            }
+            pb::mocap_result::Result::InvalidRequestData => {
+                Err(MocapError::InvalidRequestData(rpc_mocap_result.result_str).into())
             }
-            pb::mocap_result::Result::ConnectionError => Err(MavErr(MocapError::ConnectionError(
-                rpc_mocap_result.result_str,
-            ))),
-            pb::mocap_result::Result::InvalidRequestData => Err(MavErr(
-                MocapError::InvalidRequestData(rpc_mocap_result.result_str),
-            )),
         }
     }
 }

src/generated/telemetry/mod.rs

@@ -1,4 +1,4 @@
-use super::super::RequestError::{MavErr, RpcErr};
+use super::super::RequestError;
 use super::super::RequestResult;
 use futures_util::stream::{Stream, StreamExt};
 use std::pin::Pin;
@@ -212,15 +212,19 @@ impl Into<pb::Quaternion> for Quaternion {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, thiserror::Error)]
 pub enum TelemetryError {
     /// Unknown error
+    #[error("Unknown error: {0}")]
     Unknown(String),
     /// No system is connected
+    #[error("No system is connected: {0}")]
     NoSystem(String),
     /// Connection error
+    #[error("Connection error: {0}")]
     ConnectionError(String),
     /// Invalid request data
+    #[error("Invalid request: {0}")]
     InvalidRequestData(String),
 }
 
@@ -257,11 +261,11 @@ impl Stream for OdometryStream {
             Poll::Ready(Some(rpc_result)) => match rpc_result {
                 Ok(odometry_response) => match odometry_response.odometry {
                     Some(rpc_odometry) => Poll::Ready(Some(Ok(Odometry::from(rpc_odometry)))),
-                    None => Poll::Ready(Some(Err(MavErr(TelemetryError::Unknown(
+                    None => Poll::Ready(Some(Err(RequestError::Mav(TelemetryError::Unknown(
                         "Unexpected value".into(),
                     ))))),
                 },
-                Err(err) => Poll::Ready(Some(Err(RpcErr(err)))),
+                Err(err) => Poll::Ready(Some(Err(RequestError::Rpc(err)))),
             },
         }
     }

src/lib.rs

@@ -8,10 +8,15 @@ pub use generated::info;
 pub use generated::mocap;
 pub use generated::telemetry;
 
-#[derive(Debug)]
-pub enum RequestError<PluginMavErr> {
-    MavErr(PluginMavErr),
-    RpcErr(tonic::Status),
+#[derive(Debug, thiserror::Error)]
+pub enum RequestError<PluginMavErr>
+where
+    PluginMavErr: std::error::Error,
+{
+    #[error("MAVLink error: {0}")]
+    Mav(PluginMavErr),
+    #[error("RPC error: {0}")]
+    Rpc(#[from] tonic::Status),
 }
 
 pub type RequestResult<SuccessType, PluginMavErr> = Result<SuccessType, RequestError<PluginMavErr>>;