Do not rely on message text when transforming exception.

CHANGELOG.md

@@ -12,13 +12,14 @@
   - `EncoderFn` value converter for generic Dart object -> Postgres-encoded bytes
     (for values where type is not specified).
   - `DatabaseInfo` tracks information about relations and oids (currently limited to `RelationMessage` caching).
-- **Behaviour / soft-breaking changes**:
+- **Behaviour changes**, may be breaking in some cases:
   - Preparing/executing a stamement on the main connection while in a `runTx` callback will throw an exception.
   - Setting `timeout` will try to actively cancel the current statement using a new connection.
+  - `ServerException` may be transformed into `_PgQueryCancelledException` which is both `PgException` and `TimeoutException` (but no longer `ServerException`).
+- **API deprecations**:
   - Deprecated `TupleDataColumn.data`, use `.value` instead (for binary protocol messages).
   - Deprecated some logical replication message parsing method.
   - Removed `@internal`-annotated methods from the public API of `ServerException` and `Severity`.
-  - `ServerException` may be transformed into `_PgTimeoutException` which is both `PgException` and `TimeoutException` (but no longer `ServerException`).
 
 ## 3.3.0
 

lib/src/exceptions.dart

@@ -190,27 +190,23 @@ ServerException buildExceptionFromErrorFields(List<ErrorField> errorFields) {
   );
 }
 
-PgException transformServerException(
-  ServerException ex, {
-  bool timeoutTriggered = false,
-}) {
-  if (ex.code == '57014' &&
-      ex.message == 'canceling statement due to statement timeout') {
-    return _PgTimeoutException(
-      ['${ex.code}:', ex.message, ex.trace].whereType<String>().join(' '),
-    );
-  }
-  if (ex.code == '57014' && timeoutTriggered) {
-    return _PgTimeoutException(
+PgException transformServerException(ServerException ex) {
+  if (ex.code == '57014') {
+    return _PgQueryCancelledException(
       ['${ex.code}:', ex.message, ex.trace].whereType<String>().join(' '),
+      severity: ex.severity,
     );
   }
   return ex;
 }
 
-class _PgTimeoutException extends PgException implements TimeoutException {
+class _PgQueryCancelledException extends PgException
+    implements TimeoutException {
   @override
   late final duration = null;
 
-  _PgTimeoutException(super.message) : super(severity: Severity.error);
+  _PgQueryCancelledException(
+    super.message, {
+    required super.severity,
+  });
 }

lib/src/v3/connection.dart

@@ -892,11 +892,9 @@ class _PgResultStreamSubscription
     required List<ResultRow> items,
     required Duration? timeout,
   }) async {
-    bool timeoutTriggered = false;
     final cancelTimer = timeout == null
         ? null
         : Timer(timeout, () async {
-            timeoutTriggered = true;
             await connection.cancelPendingStatement();
           });
     try {
@@ -906,11 +904,6 @@ class _PgResultStreamSubscription
         affectedRows: await affectedRows,
         schema: await schema,
       );
-    } on ServerException catch (e) {
-      if (timeoutTriggered) {
-        throw transformServerException(e, timeoutTriggered: timeoutTriggered);
-      }
-      rethrow;
     } finally {
       cancelTimer?.cancel();
     }

test/timeout_test.dart

@@ -22,7 +22,15 @@ void main() {
     test('Cancel current statement through a new connection', () async {
       final f = conn.execute('SELECT pg_sleep(2);');
       await (conn as PgConnectionImplementation).cancelPendingStatement();
-      await expectLater(f, throwsA(isA<ServerException>()));
+      await expectLater(
+        f,
+        throwsA(
+          allOf(
+            isA<PgException>(),
+            isA<TimeoutException>(),
+          ),
+        ),
+      );
       // connection is still usable
       final rs = await conn.execute('SELECT 1;');
       expect(rs[0][0], 1);