​

I1 — ES Engine

Goal: ship a Zig-native JavaScript engine that is fully compatible with the latest ECMAScript edition.

​

Why this is first

Every other product surface — exclusive Bun/Deno APIs, Node-compat, frameworks, DX, desktop embed — assumes correct language semantics. Partial engines produce matrices that look green while real programs fail in surprising ways. Pre-v0.0.1 therefore gates the tag on language completeness, not on framework dogfood.

​

Success definition

You may claim ES edition compatibility for 0.0.1 only when all of the following hold:

1. Feature matrix in-scope rows are supported or dogfooded
2. Test262 CI runs on Linux for the in-scope set with zero open blockers
3. Fail-closed behavior outside the matrix (no silent wrong success)
4. Edition pin and Test262 pin are recorded in Sources

Exact in/out boundaries: Scope.

​

Current engine reality (honest)

scripty already has an early kernel: lexer/parser, bytecode interpreter, partial values, promises/microtasks, timers, local ESM, TS type strip, JSX transform. That is a starting point — not ES2026 completeness.

​

Work packages

​

Risks

​

Next

1. Read Scope
2. Track Phases
3. Update Feature matrix as work lands