Fine-tune passing errors from the server to the client

app/src/api.rs

@@ -1,4 +1,4 @@
-use anyhow::{anyhow, Error};
+use anyhow::Result;
 use lldap_model::*;
 
 use yew::callback::Callback;
@@ -9,21 +9,32 @@ use yew::services::fetch::{FetchService, FetchTask, Request, Response};
 pub struct HostService {}
 
 impl HostService {
-        pub fn list_users(&mut self, request: ListUsersRequest, callback: Callback<Result<Vec<User>, Error>>) -> Result<FetchTask, Error> {
+    pub fn list_users(
+        &mut self,
+        request: ListUsersRequest,
+        callback: Callback<Result<Vec<User>>>,
+    ) -> Result<FetchTask> {
         let url = format!("/api/users");
-        let handler = move |response: Response<Json<Result<Vec<User>, Error>>>| {
-            let (meta, Json(data)) = response.into_parts();
-            if meta.status.is_success() {
-                callback.emit(data)
-            } else {
-                callback.emit(Err(anyhow!(
-                    "{}: error getting users from /api/users",
-                    meta.status
-                )))
-            }
-        };
-        let request = Request::post(url.as_str()).header("Content-Type", "application/json").body(Json(&request)).unwrap();
+        let handler =
+            move |response: Response<Result<String>>| {
+                let (meta, maybe_data) = response.into_parts();
+                match maybe_data {
+                    Ok(data) => {
+                        if meta.status.is_success() {
+                            callback.emit(serde_json::from_str(&data).map_err(|e| {
+                                anyhow::format_err!("Could not parse response: {}", e)
+                            }))
+                        } else {
+                            callback.emit(Err(anyhow::anyhow!("[{}]: {}", meta.status, data)))
+                        }
+                    }
+                    Err(e) => callback.emit(Err(anyhow::anyhow!("Could not fetch: {}", e))),
+                }
+            };
+        let request = Request::post(url.as_str())
+            .header("Content-Type", "application/json")
+            .body(Json(&request))
+            .unwrap();
         FetchService::fetch(request, handler.into())
     }
 }
-

app/src/app.rs

@@ -41,9 +41,7 @@ impl Component for App {
                     Ok(task) => self.task = Some(task),
                     Err(e) => {
                         self.task = None;
-                        ConsoleService::log(
-                            format!("Error trying to fetch users: {:?}", e).as_str(),
-                        )
+                        ConsoleService::log(format!("Error trying to fetch users: {}", e).as_str())
                     }
                 }
             }
@@ -53,7 +51,7 @@ impl Component for App {
             }
             Msg::ListUsersResponse(Err(e)) => {
                 self.task = None;
-                ConsoleService::log(format!("Error listing users: {:?}", e).as_str())
+                ConsoleService::log(format!("Error listing users: {}", e).as_str())
             }
         }
         true

model/src/lib.rs

@@ -1,4 +1,4 @@
-use serde::{Serialize, Deserialize};
+use serde::{Deserialize, Serialize};
 
 #[derive(PartialEq, Eq, Debug, Serialize, Deserialize, Clone)]
 pub struct BindRequest {

src/infra/ldap_handler.rs

@@ -100,16 +100,10 @@ fn map_field(field: &str) -> Result<String> {
 fn convert_filter(filter: &LdapFilter) -> Result<RequestFilter> {
     match filter {
         LdapFilter::And(filters) => Ok(RequestFilter::And(
-            filters
-                .iter()
-                .map(convert_filter)
-                .collect::<Result<_>>()?,
+            filters.iter().map(convert_filter).collect::<Result<_>>()?,
         )),
         LdapFilter::Or(filters) => Ok(RequestFilter::Or(
-            filters
-                .iter()
-                .map(convert_filter)
-                .collect::<Result<_>>()?,
+            filters.iter().map(convert_filter).collect::<Result<_>>()?,
         )),
         LdapFilter::Not(filter) => Ok(RequestFilter::Not(Box::new(convert_filter(&*filter)?))),
         LdapFilter::Equality(field, value) => {

src/infra/tcp_server.rs

@@ -1,4 +1,4 @@
-use crate::domain::handler::*;
+use crate::domain::{error::Error, handler::*};
 use crate::infra::configuration::Configuration;
 use actix_files::{Files, NamedFile};
 use actix_http::HttpServiceBuilder;
@@ -16,6 +16,16 @@ async fn index(req: HttpRequest) -> actix_web::Result<NamedFile> {
     Ok(NamedFile::open(path)?)
 }
 
+fn error_to_http_response<T>(error: Error) -> ApiResult<T> {
+    ApiResult::Right(
+        match error {
+            Error::AuthenticationError(_) => HttpResponse::Unauthorized(),
+            Error::DatabaseError(_) => HttpResponse::InternalServerError(),
+        }
+        .body(error.to_string()),
+    )
+}
+
 type ApiResult<M> = actix_web::Either<web::Json<M>, HttpResponse>;
 
 async fn user_list_handler<Backend>(
@@ -26,10 +36,11 @@ where
     Backend: BackendHandler + 'static,
 {
     let req: ListUsersRequest = info.clone();
-    match data.backend_handler.list_users(req).await {
-        Ok(res) => ApiResult::Left(web::Json(res)),
-        Err(_) => ApiResult::Right(HttpResponse::InternalServerError().finish()),
-    }
+    data.backend_handler
+        .list_users(req)
+        .await
+        .map(|res| ApiResult::Left(web::Json(res)))
+        .unwrap_or_else(error_to_http_response)
 }
 
 fn api_config<Backend>(cfg: &mut web::ServiceConfig)
@@ -41,9 +52,10 @@ where
         .error_handler(|err, _req| {
             // create custom error response
             log::error!("API error: {}", err);
+            let msg = err.to_string();
             actix_web::error::InternalError::from_response(
                 err,
-                HttpResponse::Conflict().finish().into(),
+                HttpResponse::BadRequest().body(msg).into(),
             )
             .into()
         });