> ## Documentation Index > Fetch the complete documentation index at: https://docs.solved.gg/llms.txt > Use this file to discover all available pages before exploring further. # ES phases > ES-0 through ES-9 build sequence for scripty ECMAScript engine completeness. # ES phases Kernel growth is **sequential**. Do not skip values before evaluation completeness, or built-ins before a stable value model. ## Phase table ### ES-0 — Spec pin + oracle | | | | -------------- | ------------------------------------------------------------------------------------------------------------ | | **Work** | Pin ECMA-262 edition; vendor or submodule Test262; runner harness; CI job on Linux; publish pass/fail counts | | **Exit** | Every main CI run produces a Test262 report artifact; baseline X/Y known | | **Depends on** | — | ### ES-1 — Syntax | | | | -------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Work** | Lexer/parser coverage for modern syntax: classes, modules, async functions, generators, private elements, logical assignment, numeric separators, BigInt literals, import/export forms, etc. | | **Exit** | Dedicated syntax fixtures + early Test262 **parse** subset; fail closed on unsupported syntax with clear errors | | **Depends on** | ES-0 | ### ES-2 — Values and objects | | | | -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | **Work** | Complete value tags (Symbol, BigInt, …); property attributes (writable/enumerable/configurable); prototype chains; ordinary object internal methods path toward exotic objects | | **Exit** | Core object model tests; no silent attribute loss | | **Depends on** | ES-1 | ### ES-3 — Evaluation model | | | | -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Work** | Lexical environments, variable environments, `this`, `new.target`, super, completion records, try/catch/finally, loops, labeled statements, strict mode rules as required | | **Exit** | Control-flow and scope Test262 subsets green | | **Depends on** | ES-2 | ### ES-4 — GC for long runs | | | | -------------- | ------------------------------------------------------------------------------------------------------------ | | **Work** | Precise roots (frames, jobs, handles); mark–sweep freelist correct under suite; no host-held dangling Values | | **Exit** | Multi-file Test262 runs without UAF / false free; GC stress mode optional | | **Depends on** | ES-3 (can overlap late ES-3) | | **Design** | Internal `docs/vm-gc.md` in the scripty repo | ### ES-5 — Built-ins wave 1 | | | | -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Work** | `Object`, `Function`, `Array`, `String`, `Number`, `Boolean`, `Math`, `Date`, `Error` hierarchy, `JSON`, fundamental `Reflect` pieces as needed by wave 1 | | **Exit** | Corresponding [built-ins](/scripty/v0.0.1-dev/es/builtins) rows `supported` | | **Depends on** | ES-4 | ### ES-6 — Built-ins wave 2 | | | | -------------- | --------------------------------------------------------------------------------------------------------------------------- | | **Work** | `Promise`, `Symbol`, `Map`/`Set`/`WeakMap`/`WeakSet`, `RegExp`, `ArrayBuffer`/`DataView`/TypedArrays, `Atomics` if in-scope | | **Exit** | Wave 2 rows `supported` | | **Depends on** | ES-5 | ### ES-7 — Built-ins wave 3 + edition deltas | | | | -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Work** | `Proxy`/`Reflect` complete; generators/async generators; Iterator helpers; Set methods; other ES2025–ES2026 normative additions; `Intl` **only if** kept in-scope (otherwise explicit refuse) | | **Exit** | Edition feature matrix in-scope rows no longer blocked on built-ins | | **Depends on** | ES-6 | ### ES-8 — Modules (language) | | | | -------------- | -------------------------------------------------------------------------------------------------------------------------------------------- | | **Work** | Module records, linking, cyclic evaluation, top-level await ordering, import attributes as required by pin, `import.meta` host hooks minimal | | **Exit** | Module Test262 green for in-scope set | | **Depends on** | ES-5+ (practical: after ES-6) | | **Detail** | [Module system](/scripty/v0.0.1-dev/es/module-system) | ### ES-9 — Hardening | | | | -------------- | ---------------------------------------------------------------------------------- | | **Work** | Triage remaining Test262 failures; edge cases; error messages; conformance cleanup | | **Exit** | **Zero open blockers** on in-scope suite → **I1 language gate met** | | **Depends on** | ES-1…ES-8 complete for in-scope features | ## Tracking | Artifact | Update when | | ------------------------------------------------------- | ----------------------------------- | | [Feature matrix](/scripty/v0.0.1-dev/es/feature-matrix) | Feature lands or regresses | | [Built-ins](/scripty/v0.0.1-dev/es/builtins) | Built-in methods land | | [Test262](/scripty/v0.0.1-dev/es/test262) | Harness or pass-rate policy changes | | CI badge / report | Every mainline build | ## Parallelism rules | Allowed in parallel | Not allowed | | -------------------------------------------------------- | ---------------------------------------------------------------------------- | | Docs + harness while parser grows | Marking ES-9 done with open blockers | | Built-in implementations across files once ES-2/3 stable | Skipping property attributes | | Exclusive API **inventories** (I2/I3) | Claiming Bun/Deno exclusive `supported` without ES kernel for that code path | ## Related topics - [ES built-ins](/scripty/v0.0.1-dev/es/builtins.md) - [Roadmap](/scripty/v0.0.1-dev/roadmap.md) - [ES module system](/scripty/v0.0.1-dev/es/module-system.md) - [I1 — ES Engine](/scripty/v0.0.1-dev/es/index.md) - [Pre-v0.0.1 program](/scripty/v0.0.1-dev/index.md)