Emit DEFAULT without parens for simple identifiers

The DEFAULT_GENERATED path wraps the translated expression in parens
unconditionally. Real SQLite's PRAGMA strips outer parens round-trip;
Turso keeps them. For simple identifier defaults (CURRENT_TIMESTAMP,
etc.) SQLite accepts the unwrapped form; emit without parens so
Turso's PRAGMA matches SQLite's.

Fixes testCreateTableWithDefaultNowFunction. testCreateTableWithDefaultExpressions
still fails because 1 + 2 needs parens for SQLite syntax.

Author: JanJakes

.github/workflows/phpunit-tests-turso.yml

@@ -1240,6 +1240,41 @@ jobs:
           open(path, 'w').write(src.replace(old, new, 1))
           print('patched CHECK TABLE missing-table check')
 
+          # 15. DEFAULT_GENERATED path wraps the translated expression in parens
+          #     unconditionally: `DEFAULT (<expr>)`. Real SQLite strips the outer
+          #     parens on round-trip through PRAGMA; Turso keeps them. For simple
+          #     identifiers (e.g. CURRENT_TIMESTAMP), SQLite accepts the unwrapped
+          #     form too, so emit without parens there.
+          path = 'src/sqlite/class-wp-pdo-mysql-on-sqlite.php'
+          src = open(path).read()
+          old = (
+              "\t\t\t\t} elseif ( str_contains( $column['EXTRA'], 'DEFAULT_GENERATED' ) ) {\n"
+              "\t\t\t\t\t// Handle DEFAULT values with expressions (DEFAULT_GENERATED).\n"
+              "\t\t\t\t\t// Translate the default clause from MySQL to SQLite.\n"
+              "\t\t\t\t\t$ast            = $this->create_parser( 'SELECT ' . $column['COLUMN_DEFAULT'] )->parse();\n"
+              "\t\t\t\t\t$expr           = $ast->get_first_descendant_node( 'selectItem' )->get_first_child_node();\n"
+              "\t\t\t\t\t$default_clause = $this->translate( $expr );\n"
+              "\t\t\t\t\t$query         .= sprintf( ' DEFAULT (%s)', $default_clause );\n"
+              "\t\t\t\t}"
+          )
+          new = (
+              "\t\t\t\t} elseif ( str_contains( $column['EXTRA'], 'DEFAULT_GENERATED' ) ) {\n"
+              "\t\t\t\t\t$ast            = $this->create_parser( 'SELECT ' . $column['COLUMN_DEFAULT'] )->parse();\n"
+              "\t\t\t\t\t$expr           = $ast->get_first_descendant_node( 'selectItem' )->get_first_child_node();\n"
+              "\t\t\t\t\t$default_clause = $this->translate( $expr );\n"
+              "\t\t\t\t\tif ( preg_match( '/^[A-Za-z_][A-Za-z_0-9]*$/', trim( $default_clause ) ) ) {\n"
+              "\t\t\t\t\t\t// Simple identifier (e.g. CURRENT_TIMESTAMP): omit parens\n"
+              "\t\t\t\t\t\t// so Turso's PRAGMA round-trip matches SQLite.\n"
+              "\t\t\t\t\t\t$query .= ' DEFAULT ' . $default_clause;\n"
+              "\t\t\t\t\t} else {\n"
+              "\t\t\t\t\t\t$query .= sprintf( ' DEFAULT (%s)', $default_clause );\n"
+              "\t\t\t\t\t}\n"
+              "\t\t\t\t}"
+          )
+          assert old in src, 'DEFAULT_GENERATED block not found'
+          open(path, 'w').write(src.replace(old, new, 1))
+          print('patched DEFAULT_GENERATED simple-identifier unwrap')
+
           # 14. Update Translation_Tests::testHexadecimalLiterals to match
           #     the hex-literal alias force patch (which needs to stay so
           #     Turso doesn't mangle x'417a' into 17a' at runtime).