Opt-in strict-types enforcement

Date: 2026-04-30 Area: runtime

Strict-types runtime enforcement is now an explicit --strict-types CLI / "strict-types" config flag (default off) that works in both interpreter and bytecode mode. Previously the bytecode VM implicitly enforced type annotations and the interpreter silently ignored them, with a read-only Goccia.strictTypes JS global advertising the mode. The new model: enforcement is opt-in regardless of execution mode, the bytecode compiler gates OP_CHECK_TYPE emission on the flag, the interpreter records type hints on lexical bindings (TLexicalBinding.TypeHint) and enforces them in AssignBinding / variable declaration / parameter binding via the shared Goccia.Types.Enforcement unit, and the Goccia.strictTypes global is removed in favour of directory-level goccia.json config (mirroring --asi / --compat-var). language.md § Types as Comments.