Chart full TypeScript toolchain compatibility

[metaphorics]

Destination

An approved, implementation-ready compatibility program for a pure-Rust TypeScript 7.0.2 toolchain: current accepted language history, TypeScript-compatible Node API shim, Node 24 LTS host support, 100% of applicable official TypeScript tests, and behavioral diagnostic/runtime parity delivered as vertical conformance slices.

Notes

Planning only. Consult ground-latest, source-driven, research, explore, and spine. Treat .reference/ as study-only and never copy implementation code. The official TypeScript suite is the compatibility oracle. Existing verified compiler work must be preserved and shipped as a clean prerequisite stack.

Decisions so far

• Set the compatibility destination and proof contract — Full TypeScript 7.0.2 toolchain in pure Rust; current accepted history, Node API shim, Node 24, behavioral parity, 100% applicable-suite pass, vertical slices.
• Pin the TypeScript 7.0.2 conformance oracle — Pin typescript@7.0.2, typescript-go@2bd066d8…, tag typescript/v7.0.2, and the imported TypeScript suite at 4d4f005c…; classify applicability per observable facet.
• Inventory current compiler conformance coverage — The nine-crate Rust compiler has working frontend, bytecode, interpreter, JIT, AOT, Node host, corpus, and formal-gate layers, with partial semantic and toolchain coverage recorded in the research ledger.
• Map the TypeScript compiler and language-service API — Treat modular RPC, snapshots/projects/program/checker, filesystem hosts, LSP, watch/build, resolution, declaration emit, cancellation, and AST APIs as linked compatibility domains.
• Map the Node 24 host compatibility surface — Node 24 Krypton is the host baseline; loader/process/Buffer/timers/fs/path/url/events/assert/streams are mandatory, with conditional host domains classified in the research artifact.

Not yet specified

• Failure triage and compatibility-ledger ownership after the official suite and current gaps are known.
• Release staging, migration, and rollback policy after slice order and CI design settle.
• Whether compatibility-sensitive unstable TypeScript subpaths require exact version locking or a supported adapter policy.

Out of scope

• Recreating TypeScript behavior removed before 7.0.2.
• Browser/DOM host APIs beyond the chosen ECMAScript + Node 24 contract.
• Copying implementation code from .reference/ or upstream TypeScript.

[coderabbitai]

🔗 Related PRs

#2 - fix(formal): synchronize bytecode format version [open]
#3 - fix(runtime): clean up test helper allocations [open]

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[metaphorics]

Native transport replanning is charted in Chart the private napi-rs transport replacement for the Node facade, now linked as a child map.