Fix static evaluation TypeCast str->bool bug (#8113)

`<bool>'false'` was evaluated as `True`.

edb/ir/staeval.py

@@ -420,10 +420,35 @@ def cast_const_to_python(ir: irast.TypeCast, schema: s_schema.Schema) -> Any:
     schema, stype = irtyputils.ir_typeref_to_type(schema, ir.to_type)
     pytype = scalar_type_to_python_type(stype, schema)
     sval = evaluate_to_python_val(ir.expr, schema=schema)
-    if sval is None:
-        return None
-    elif isinstance(sval, tuple):
-        return tuple(pytype(elem) for elem in sval)
+    return python_cast(sval, pytype)
+
+
+@functools.singledispatch
+def python_cast(sval: Any, pytype: type) -> Any:
+    return pytype(sval)
+
+
+@python_cast.register(type(None))
+def python_cast_none(sval: None, pytype: type) -> None:
+    return None
+
+
+@python_cast.register(tuple)
+def python_cast_tuple(sval: Tuple[Any, ...], pytype: type) -> Any:
+    return tuple(python_cast(elem, pytype) for elem in sval)
+
+
+@python_cast.register(str)
+def python_cast_str(sval: str, pytype: type) -> Any:
+    if pytype is bool:
+        if sval.lower() == 'true':
+            return True
+        elif sval.lower() == 'false':
+            return False
+        else:
+            raise errors.InvalidValueError(
+                f"invalid input syntax for type bool: {sval!r}"
+            )
     else:
         return pytype(sval)
 

edb/lib/_testmode.edgeql

@@ -132,6 +132,11 @@ ALTER TYPE cfg::AbstractConfig {
         SET default := cfg::TestEnum.One;
     };
 
+    CREATE PROPERTY boolprop -> std::bool {
+        CREATE ANNOTATION cfg::internal := 'true';
+        SET default := true;
+    };
+
     CREATE PROPERTY __pg_max_connections -> std::int64 {
         CREATE ANNOTATION cfg::internal := 'true';
         CREATE ANNOTATION cfg::backend_setting := '"max_connections"';

tests/test_server_config.py

@@ -1066,6 +1066,45 @@ async def test_server_proto_configure_08(self):
                 CONFIGURE INSTANCE RESET _pg_prepared_statement_cache_size;
             ''')
 
+    async def test_server_proto_configure_09(self):
+        con2 = await self.connect(database=self.con.dbname)
+        default_value = await con2.query_single(
+            'SELECT assert_single(cfg::Config).boolprop'
+        )
+        try:
+            for value in [True, False, True, False]:
+                await self.con.execute(f'''
+                    CONFIGURE SESSION SET boolprop := <bool>'{value}';
+                ''')
+                # The first immediate query is likely NOT syncing in-memory
+                # state to the backend connection, so this will test that
+                # the state in the SQL temp table is correctly set.
+                await self.assert_query_result(
+                    '''
+                    SELECT cfg::Config.boolprop
+                    ''',
+                    [value],
+                )
+                # Now change the state on the backend connection, hopefully,
+                # by running a query with con2 with different state.
+                self.assertEqual(
+                    await con2.query_single(
+                        'SELECT assert_single(cfg::Config).boolprop'
+                    ),
+                    default_value,
+                )
+                # The second query shall sync in-memory state to the backend
+                # connection, so this tests if the statically evaluated bool
+                # value is correct.
+                await self.assert_query_result(
+                    '''
+                    SELECT cfg::Config.boolprop
+                    ''',
+                    [value],
+                )
+        finally:
+            await con2.aclose()
+
     async def test_server_proto_configure_describe_system_config(self):
         try:
             conf1 = "CONFIGURE INSTANCE SET singleprop := '1337';"