Error handling with thiserror (#494)

* feat(db): add indexes for foreign key reference columns

* fix(db): index naming and missing semicolons

* dep(backend): update axum

* fix(backend): remove testing jwt handlers

* feat(backend): Add custom jwt validator and header

* feat(backend): basic error handling enum

* fix(backend): ran cargo fmt

* fix(backend): remove unused imports

* Change to using `thiserror`

* remove 'Error' from logic error names

backend/server/Cargo.toml

@@ -14,6 +14,7 @@ sqlx = { version = "0.7", features = ["runtime-tokio-rustls", "postgres", "time"
 
 # Important secondary crates
 anyhow = "1.0"
+thiserror = "1.0"
 serde = { version = "1.0", features = ["derive"] }
 reqwest = { version = "0.11", features = ["json"] }
 serde_json = "1.0"

backend/server/src/models/auth.rs

@@ -91,6 +91,7 @@ where
 
         let claims =
             decode_auth_token(token, decoding_key, jwt_validator).ok_or(ChaosError::NotLoggedIn)?;
+
         let pool = &app_state.db;
         let possible_user = is_super_user(claims.sub, pool).await;
 
@@ -102,6 +103,6 @@ where
             }
         }
 
-        Err(ChaosError::NotLoggedIn)
+        Err(ChaosError::Unauthorized)
     }
 }

backend/server/src/models/error.rs

@@ -3,31 +3,42 @@ use axum::response::{IntoResponse, Redirect, Response};
 
 /// Custom error enum for Chaos.
 ///
-/// Handles all anyhow errors (when `?` is used) alongside
+/// Handles all errors thrown by libraries (when `?` is used) alongside
 /// specific errors for business logic.
+#[derive(thiserror::Error, Debug)]
 pub enum ChaosError {
+    #[error("Not logged in")]
     NotLoggedIn,
+
+    #[error("Not authorized")]
     Unauthorized,
+
+    #[error("Forbidden operation")]
     ForbiddenOperation,
-    ServerError(anyhow::Error),
+
+    #[error("SQLx error")]
+    DatabaseError(#[from] sqlx::Error),
+
+    #[error("Reqwest error")]
+    ReqwestError(#[from] reqwest::Error),
+
+    #[error("OAuth2 error")]
+    OAuthError(#[from] oauth2::RequestTokenError<oauth2::reqwest::Error<reqwest::Error>, oauth2::StandardErrorResponse<oauth2::basic::BasicErrorResponseType>>)
 }
 
+/// Implementation for converting errors into responses. Manages error code and message returned.
 impl IntoResponse for ChaosError {
     fn into_response(self) -> Response {
         match self {
             ChaosError::NotLoggedIn => Redirect::temporary("/auth/google").into_response(),
             ChaosError::Unauthorized => (StatusCode::UNAUTHORIZED, "Unauthorized").into_response(),
             ChaosError::ForbiddenOperation => (StatusCode::FORBIDDEN, "Forbidden operation").into_response(),
-            ChaosError::ServerError(e) => (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()).into_response()
+            ChaosError::DatabaseError(db_error) => match db_error {
+                // We only care about the RowNotFound error, as others are miscellaneous DB errors.
+                sqlx::Error::RowNotFound => (StatusCode::NOT_FOUND, "Not found").into_response(),
+                _ => (StatusCode::INTERNAL_SERVER_ERROR, "Internal server error").into_response(),
+            },
+            _ => (StatusCode::INTERNAL_SERVER_ERROR, "Internal server error").into_response()
         }
     }
 }
-
-impl<E> From<E> for ChaosError
-where
-    E: Into<anyhow::Error>,
-{
-    fn from(err: E) -> Self {
-        ChaosError::ServerError(err.into())
-    }
-}