A union may now hold one promise beside data members (`T | Promise<T>`,
`Promise<R | void> | R | void`). The union tag is the `instanceof Promise`
test, and every operation keeps Node's microtask timing: `await` awaits the
promise arm or takes the one non-thenable turn, an async `return` (block
bodies, concise arrows, then handlers) adopts the promise arm after the
function's own finally blocks, `Promise.resolve` returns the promise arm as
is, and `typeof (u as any).then` reads the tag. Data arms that declare
`then`, two promise arms, and function arms beside a promise stay refused
with diagnostics. Inferred JavaScript literals that mix promises and values
keep the checked-dynamic array.
Rest parameters typed `unknown[]` or `any[]` in TypeScript use the
checked-dynamic variadic ABI that JavaScript rest parameters already use,
including spread forwarding (`(...args) => handler(...args)`).
Functions are now Map values, Map keys and Set elements, compared by
closure identity.
Two pre-existing bugs in the same area are fixed: an async lambda in a
`Promise<void> | void` slot got a `Promise<union>` ABI and threw when called
through the slot, and `return cb()` of such a callback in an async function
dropped the promise instead of adopting it.
The retired-engine 2251 and 2790 diagnostics fixtures (tagged templates
with `any[]` rest tags) now compile and match Node, so they move to the
corpus as 6248 and 6249.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- Support boolean, bigint, and mixed value keys in native Maps and Sets.
- Reuse key hashes and copy collections directly into compact storage.
- Preserve collection identity, ordering, iteration, and ownership behavior.
- Run production scope and closure capture logic with native TypeScript 7 symbols.
- Give lowering caches explicit pass ownership and stable symbol identities.
- Support reference collection arrays and optional Set seeds on both native backends.
- Compile the memoizing TypeScript checker with project-owned caches and explicit disposal.
- Support nested Map and Set values with native identity and cycle tracing.
- Preserve synthetic AST fragments and isolate semantic answers across snapshots.
* feat(compiler): advance self-hosting with identity collections
- Support reference identity in Maps and Sets, including unions and cycle cleanup.
- Run production integer-range analysis natively with typed IR traversal.
- Add differential coverage for native analyses and collection behavior.
* chore: ignore generated output directories
- Exclude generated output directories from version control.
