fix(postgres): decode PgDatabaseError for ErrorResponse

Author: abonander

sqlx-postgres/src/connection/stream.rs

@@ -98,7 +98,7 @@ impl PgStream {
             match message.format {
                 BackendMessageFormat::ErrorResponse => {
                     // An error returned from the database server.
-                    return Err(PgDatabaseError(message.decode()?).into());
+                    return Err(message.decode::<PgDatabaseError>()?.into());
                 }
 
                 BackendMessageFormat::NotificationResponse => {

sqlx-postgres/src/error.rs

@@ -3,10 +3,10 @@ use std::fmt::{self, Debug, Display, Formatter};
 
 use atoi::atoi;
 use smallvec::alloc::borrow::Cow;
-
+use sqlx_core::bytes::Bytes;
 pub(crate) use sqlx_core::error::*;
 
-use crate::message::{Notice, PgSeverity};
+use crate::message::{BackendMessage, BackendMessageFormat, Notice, PgSeverity};
 
 /// An error returned from the PostgreSQL database.
 pub struct PgDatabaseError(pub(crate) Notice);
@@ -219,6 +219,16 @@ impl DatabaseError for PgDatabaseError {
     }
 }
 
+// ErrorResponse is the same structure as NoticeResponse but a different format code.
+impl BackendMessage for PgDatabaseError {
+    const FORMAT: BackendMessageFormat = BackendMessageFormat::ErrorResponse;
+
+    #[inline(always)]
+    fn decode_body(buf: Bytes) -> std::result::Result<Self, Error> {
+        Ok(Self(Notice::decode_body(buf)?))
+    }
+}
+
 /// For reference: <https://www.postgresql.org/docs/current/errcodes-appendix.html>
 pub(crate) mod error_codes {
     /// Caused when a unique or primary key is violated.