Copy better error handling over from rauth.

src/util/mod.rs

@@ -2,8 +2,9 @@ use rand::{distributions::Alphanumeric, Rng};
 use std::collections::HashSet;
 use std::iter::FromIterator;
 
-pub mod captcha;
 pub mod email;
+pub mod result;
+pub mod captcha;
 pub mod variables;
 
 pub fn vec_to_set<T: Clone + Eq + std::hash::Hash>(data: &[T]) -> HashSet<T> {

src/util/result.rs

@@ -0,0 +1,66 @@
+use rocket::response::{self, Responder, Response};
+use rocket::http::{ContentType, Status};
+use rocket::request::Request;
+use serde::Serialize;
+use std::io::Cursor;
+use snafu::Snafu;
+use json;
+
+#[derive(Serialize, Debug, Snafu)]
+#[serde(tag = "type")]
+pub enum Error {
+    #[snafu(display("This error has not been labelled."))]
+    #[serde(rename = "unlabelled_error")]
+    LabelMe,
+    /* #[snafu(display("Failed to validate fields."))]
+    #[serde(rename = "failed_validation")]
+    FailedValidation { error: ValidationErrors },
+    #[snafu(display("Encountered a database error."))]
+    #[serde(rename = "database_error")]
+    DatabaseError,
+    #[snafu(display("Encountered an internal error."))]
+    #[serde(rename = "internal_error")]
+    InternalError,
+    #[snafu(display("Operation did not succeed."))]
+    #[serde(rename = "operation_failed")]
+    OperationFailed,
+    #[snafu(display("Missing authentication headers."))]
+    #[serde(rename = "missing_headers")]
+    MissingHeaders,
+    #[snafu(display("Invalid session information."))]
+    #[serde(rename = "invalid_session")]
+    InvalidSession,
+    #[snafu(display("User account has not been verified."))]
+    #[serde(rename = "unverified_account")]
+    UnverifiedAccount,
+    #[snafu(display("This user does not exist!"))]
+    #[serde(rename = "unknown_user")]
+    UnknownUser,
+    #[snafu(display("Email is use."))]
+    #[serde(rename = "email_in_use")]
+    EmailInUse,
+    #[snafu(display("Wrong password."))]
+    #[serde(rename = "wrong_password")]
+    WrongPassword, */
+}
+
+pub type Result<T, E = Error> = std::result::Result<T, E>;
+
+/// HTTP response builder for Error enum
+impl<'r> Responder<'r, 'static> for Error {
+    fn respond_to(self, _: &'r Request<'_>) -> response::Result<'static> {
+        let status = match self {
+            Error::LabelMe => Status::InternalServerError
+        };
+
+        // Serialize the error data structure into JSON.
+        let string = json!(self).to_string();
+
+        // Build and send the request.
+        Response::build()
+            .sized_body(string.len(), Cursor::new(string))
+            .header(ContentType::new("application", "json"))
+            .status(status)
+            .ok()
+    }
+}