Show a better message for SET/RESET/SHOW over SQL native protocol (#8056

)

edb/pgsql/resolver/dispatch.py

@@ -108,7 +108,7 @@ def _raise_unsupported(expr: pgast.Base) -> typing.Never:
     # title case to spaces
     pretty_name = re.sub(r'(?<!^)(?=[A-Z])', ' ', pretty_name).upper()
 
-    raise errors.QueryError(
+    raise errors.UnsupportedFeatureError(
         f'not supported: {pretty_name}',
         span=expr.span,
         pgext_code=pgerror.ERROR_FEATURE_NOT_SUPPORTED,

edb/server/compiler/compiler.py

@@ -568,7 +568,7 @@ def compile_sql(
             apply_access_policies_sql=apply_access_policies_sql,
             disambiguate_column_names=False,
             backend_runtime_params=self.state.backend_runtime_params,
-            protocol_version=(-3, 0),  # emulated PG binary protocol version
+            protocol_version=defines.POSTGRES_PROTOCOL,
         )
 
     def compile_serialized_request(

edb/server/compiler/sql.py

@@ -100,6 +100,10 @@ def compile_sql(
         )
 
         if isinstance(stmt, (pgast.VariableSetStmt, pgast.VariableResetStmt)):
+            if protocol_version != defines.POSTGRES_PROTOCOL:
+                from edb.pgsql import resolver as pg_resolver
+                pg_resolver.dispatch._raise_unsupported(stmt)
+
             value: Optional[dbstate.SQLSetting]
             if isinstance(stmt, pgast.VariableSetStmt):
                 value = pg_arg_list_to_python(stmt.args)
@@ -137,6 +141,10 @@ def compile_sql(
                 unit.capabilities |= enums.Capability.SESSION_CONFIG
 
         elif isinstance(stmt, pgast.VariableShowStmt):
+            if protocol_version != defines.POSTGRES_PROTOCOL:
+                from edb.pgsql import resolver as pg_resolver
+                pg_resolver.dispatch._raise_unsupported(stmt)
+
             unit.get_var = stmt.name
             unit.frontend_only = (
                 stmt.name in FE_SETTINGS_MUTABLE
@@ -146,6 +154,10 @@ def compile_sql(
                 unit.command_complete_tag = dbstate.TagPlain(tag=b"SHOW")
 
         elif isinstance(stmt, pgast.SetTransactionStmt):
+            if protocol_version != defines.POSTGRES_PROTOCOL:
+                from edb.pgsql import resolver as pg_resolver
+                pg_resolver.dispatch._raise_unsupported(stmt)
+
             if stmt.scope == pgast.OptionsScope.SESSION:
                 unit.set_vars = {
                     f"default_{name}": (

edb/server/defines.py

@@ -86,6 +86,9 @@
 MIN_PROTOCOL: ProtocolVersion = (1, 0)
 CURRENT_PROTOCOL: ProtocolVersion = (3, 0)
 
+# Emulated PG binary protocol
+POSTGRES_PROTOCOL: ProtocolVersion = (-3, 0)
+
 MIN_SUGGESTED_CLIENT_POOL_SIZE = 10
 MAX_SUGGESTED_CLIENT_POOL_SIZE = 100
 

edb/server/protocol/pg_ext.pyx

@@ -428,7 +428,12 @@ cdef class PgConnection(frontend.FrontendConnection):
                 str(exc), detail=exc.details, severity="FATAL"
             )
         elif isinstance(exc, errors.UnsupportedFeatureError):
-            exc = pgerror.FeatureNotSupported(str(exc))
+            exc = pgerror.new(
+                pgerror.ERROR_FEATURE_NOT_SUPPORTED,
+                str(exc),
+                L=str(exc.line) if exc.line >= 0 else None,
+                P=str(exc.position + 1) if exc.position >= 0 else None,
+            )
         elif isinstance(exc, errors.EdgeDBError):
             args = dict(hint=exc.hint, detail=exc.details)
             if exc.line >= 0:

tests/test_sql_query.py

@@ -2720,3 +2720,32 @@ async def test_native_sql_query_15(self):
             'SELECT title FROM "Content" ORDER BY title',
             [{'title': 'Forrest Gump'}]
         )
+
+    async def test_native_sql_query_16(self):
+        with self.assertRaisesRegex(
+            edgedb.UnsupportedFeatureError,
+            "not supported: VARIABLE SET",
+            _position=14,  # this point to `1`, but hey, better than nothing
+        ):
+            await self.assert_sql_query_result(
+                'SET my_var TO 1',
+                []
+            )
+
+        with self.assertRaisesRegex(
+            edgedb.UnsupportedFeatureError,
+            "not supported: VARIABLE RESET",
+        ):
+            await self.assert_sql_query_result(
+                'RESET my_var',
+                []
+            )
+
+        with self.assertRaisesRegex(
+            edgedb.UnsupportedFeatureError,
+            "not supported: VARIABLE SHOW",
+        ):
+            await self.assert_sql_query_result(
+                'SHOW my_var',
+                []
+            )