fetch's input under @types/node is string | URL | Request. A union with a
checked-dynamic arm collapses to the checked-dynamic representation only
when every sibling survives the collapse; URL did not qualify, so the type
(and anything typed as typeof globalThis.fetch, such as a custom fetch cast
through unknown) did not compile. URL's handle boxes by reference, keeps its
accessors and setters, answers instanceof URL and checks back out to the
typed value, so URL arms now join the collapse. A fetch() input typed
string | URL also converts through the checked-dynamic input path instead
of being narrowed to a string, which threw on the URL arm.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The net unit drained its poller every time the loop came back to the I/O
station, including the restarts that drain microtasks. I/O that became
ready during the iteration's own callbacks (a loopback connect started by
one of them) was delivered before the check phase, so setImmediate
callbacks queued earlier ran after it; Node delivers it in the next
iteration's poll phase. The poller now drains once per iteration (a full
batch keeps draining), reopening after the check phase. Back-to-back
undici requests now reuse connections like Node, so the fixtures drop
their setImmediate turn between requests.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@types/node's fetch declarations (undici-types) spell the Headers methods
and the body mixin as function-typed properties (readonly append: (...) =>
void), where scriptc's own declarations use methods. The receiver call
lowering treated such a standard-library property as a stored callback:
Headers.forEach was refused at build time and append/get/set/... compiled
to a runtime 'is not a function'. Standard-library members now take the
shared receiver dispatch either way.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
#1399 removed CheckerFacade.declarationsOf and valueDeclarationOf. #1407 and
#1351 merged after it with calls to them, so main does not type-check. Read
symbol.declarations and symbol.valueDeclaration instead, as the rest of the
compiler does.
A construction through a plain function stamps the prototype with the
name of the function in its `constructor` property, for util.inspect.
The stamp pointed at the function's name. A bound function's name
("bound " and the target's name) is a string the bound function owns,
so after the `constructor` property was replaced and the bound function
released, inspecting an instance read freed memory. The stamp now holds
a copy of the name, freed with the stamp at exit.
The corpus program constructs through functions whose prototype's
`constructor` is a bound function (and a bound function of one), then
replaces the property and inspects the instances.
A TypeScript implementation over node:net, node:tls and node:events:
Dispatcher, Client (HTTP/1.1 with keep-alive), Pool, Agent,
buildConnector, request(), errors, the global dispatcher, fetch, Headers
and the diagnostics_channel publications, with per-version behavior.
Differential npm cases run the vendored real undici under Node.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
package-shims.ts registers implementation modules shipped with the
compiler per package and major version (chosen by the importer's
installed version) and reads the project's never-loaded packages from
"scriptc": { "packages": { "<name>": "unloaded" } }. Module edges go
through resolveProjectImport; the npm resolution, the npm-edge walk and
the --npm-static set skip such packages; the tsgo host reads a shimmed
package's index.d.ts as a re-export of its implementation; an unloaded
package's require() throws Node's not-installed MODULE_NOT_FOUND.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
@types/node 20 and older declare NodeJS.Timeout and NodeJS.Immediate as
classes; 22+ (and scriptc's own declarations) declare interfaces. Accept
both as the native timer handle.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A statement-level require() of a package nothing installed threw a plain
Error; the expression form already carried Node's MODULE_NOT_FOUND code.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Relational string operators (`<`, `<=`, `>`, `>=`) compared the UTF-8
bytes, which is code-point order. Node compares UTF-16 code units, so the
results differed for characters above U+FFFF against U+E000..U+FFFF and
for lone surrogates against surrogate pairs. The default `sort()`
comparator, `util.inspect` with `sorted: true` and dynamic comparisons
already used UTF-16 order; the default comparator of a dynamic array's
`sort()` did not.
Typed comparisons and the dynamic array sort now use `scr_str_cmp_u16`,
and the IR's `strCmp` node no longer has a `utf16` flag. The two orders
agree unless both of the first differing bytes are at least 0xED, so:
- the inline wrapper decides differing first words, or last words of
equal lengths up to 16 bytes, in byte order when neither word has a
byte of at least 0xED (a SWAR test). Other differing words, and the
first bytes of shorter strings, decide by their first differing byte:
in byte order when one of the two is below 0xED, and by plane when both
are lead bytes from 0xEE to 0xF4 (a supplementary character orders
below U+E000..U+FFFF);
- otherwise a proven-ASCII string on either side compares with `memcmp`
(`scr_str_cmp`), and other pairs call `scr_str_cmp_u16_bytes`. It finds
the first differing byte with words up to byte 32, then with 32-byte
SSE2 or NEON blocks where the target has them. The call is marked as
only reading its arguments, so repeated comparisons of one pair merge.
- `scr_str_cmp_u16` itself takes the same `memcmp` path for proven-ASCII
strings.
The native compiler sorts record fields with `<` and checks the order
with `sort()`, so it reported SC9001 for 5888-inspect-sorted.ts, whose
object has the keys "\u{1F600}" and "\uffff". 5888 runs in the
native-frontend self-host check. Adds corpus 6023.
`globalThis as { [KEY]?: State }` is the usual way for several modules
to share process-wide state. globalThis lowers to a checked-dynamic
value, and asserting a checked-dynamic value to a record or array type
took the checked conversion, which builds a new native value. A write
through the asserted value went to that copy, so other modules never
saw it; string-keyed and index-signature views threw "expected object".
- An assertion of the global object (globalThis, global, also through
`as unknown as`) keeps the checked-dynamic value when the conversion
would copy, so member reads and writes reach the global object.
- File-scope and local bindings of such an assertion hold the global
object (collectGlobals, lowerVarDecl), so an exported
`const state = globalThis as ...` works across modules.
- The divergence scan no longer reports these assertions as SC6001
width copies.
- Runtime: one global-object box per thread (scr_global_object), which
globalThis, global and globalThis.globalThis all answer, and direct
`globalThis[symbol]` accesses use that box's symbol-keyed properties,
so every spelling of the global object sees one property.
Other checked-dynamic values keep the checked conversion: a native
value held as unknown unwraps by identity there, and a checked-dynamic
tree is copied at the documented boundary.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
In a generic function, `node instanceof Identifier || node instanceof
PrivateIdentifier` narrows `node` to `T & PrivateIdentifier` when
Identifier has every member PrivateIdentifier has: TypeScript reduces the
union of the two intersections by structural subtyping. The read was
lowered as a downcast to PrivateIdentifier, and the narrowing guard
aborted when it held an Identifier. tsc-ts's NodeFactory.cloneNode has
this pattern, so declaration emit aborted.
When the checker types a read of a type-parameter intersection as a
subclass, and another class under the value's class is assignable to that
subclass without extending it, the read is now a class union over those
classes, and member reads and method calls on it dispatch over the union.
When this instantiation's class is unrelated to the narrowed class but
assignable to it (`T = Identifier`), member calls use the instantiation's
class. A union method helper whose body lowering is refused is no longer
left registered without a body.
paramShapes, which builds the parameters of an instantiated signature
(generic call instances and the erased instance that a method value or
a reflected prototype slot uses), refused an optional parameter unless
its type had an undefined union arm. An interface view implemented by a
class (`handle?: Handle | null`) and an erased type parameter map to the
checked-dynamic type, which holds undefined directly; paramShape, the
declared-signature path, already accepts it.
Direct calls of such a method failed with "optional parameters of type
'unknown'", and reflecting its class prototype from the dynamic-dispatch
fixpoint raised the same refusal outside any statement and crashed the
compiler with an uncaught PoisonError. paramShapes now treats the
parameter as omittable, so the instance lowers.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The native CLI built from main aborted on the record-boundaries and
value-objects benchmarks with "a narrowed value does not have the type its
narrowing proved". record-results.ts builds recordSet statements in a map
callback whose value field is a recordGet literal. Converting that array
into IrStmt[] chose the break/continue arm: the literal also fits the
shorter varRef-like expression arms, so its conversion into IrExpr was
ambiguous, and an ambiguous field conversion made widthLiftPlan drop every
arm that needed it. The one arm left was break/continue, reached by
dropping obj, shapeId, field and value. The record kept kind "recordSet"
under the break/continue tag, so mapStmtChildren's narrowing guard aborted.
IR record shapes keep the discriminant as a plain string, so a record's
layout alone cannot pick its arm. When a record that carries a
discriminated union's discriminant field fits several arms, widthLiftPlan
now plans a route through every arm it converts into, selected at run time
by the discriminant's value, as JavaScript does (a value no arm names
throws the catchable TypeError). Conversions that resolved before are
unchanged; the zero-cost gate shows identical IR, LLVM and executables for
the benchmarks and the corpus, and the native CLI now compiles every
benchmark workload.
The test used `const { length } = [1, 2] as number[]` as its coverage
blocker. That compiles now, so no diagnostic was left to replay. The blocker
destructures a `number[] | string` union instead, which keeps the SC1031
object-pattern fence. The comment-only replay and code-edit relower
assertions are unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
jose 6.2.12 now compiles natively through its root entry (`import { jwtVerify,
errors } from "jose"`), from TypeScript and JavaScript, with chained SignJWT
builders and string durations:
- A discarded `a && b;` / `a || b;` statement whose value form fails on its own
result type (jose's secs(): `(!m || m[4] && m[1]) && invalid()`) lowers as
`if (a) b;` / `if (!a) b;`. The value form still lowers first, so statements
that compiled before are unchanged.
- In JavaScript, a number-keyed read on a `T[] | null | undefined` value outside
an optional chain (`m[2]` after a statement ruled `m` non-null) reads the
array arm like any element read: a group that did not participate is
undefined instead of a trap.
- A JavaScript fluent method whose returns all end in `this` (including comma
sequences) narrows a used call result back to the receiver's subclass. A
receiver lowered at an ancestor of the class a call needs is bridged with a
verified downcast instead of an upcast the validator rejected (the
"upcast JWTClaimsBuilder does not extend SignJWT" internal error).
- `typeof navigator` is "object" and `navigator.userAgent` is "Node.js/24", as
in Node 24, for the free name in JavaScript and under @types/node. Both fold
to literals; other members refuse by name.
- TypeScript object destructuring of an `any` result of a JavaScript function
(jose's jwtVerify) reads its members like the member reads that already
compiled.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
tests/coverage-fixtures/mixed.ts used `const { length: firstItem } = items`
as its SC1031 example. Object patterns of positions and length over arrays
compile now, so coverage counted 13/13 static. The example now destructures
a union source (array | string), which keeps the SC1031 object-pattern fence
at the same line and column; only the message's source kind changes, from
array-typed to union-typed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A JavaScript `var` binding hoists to its function, and its slot was
created with the checker's type before the initializer lowered. When the
initializer was an existing checked-dynamic object (an element of an
array built with push, a find result, the object a function returns),
the record-typed slot held a converted copy: writes through the binding
missed the object that the array or the function's caller still held,
and `===` against it was false. `let` and `const` already lowered the
initializer first and kept such a value checked-dynamic.
A `var` initialized with an existing value now lowers the initializer
before creating the slot, and a checked-dynamic value gets a
checked-dynamic slot. The same applies to `for (var x of ...)`, to array
destructuring with `var`, `let` and `const`, and to file-scope bindings,
whose module-entry `undefined` store follows the slot's final type. A
literal holding such an object builds checked-dynamic for a `var` as it
already did for `let`. TypeScript files and annotated bindings are
unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
fs-shims now gets past Buffer.isBuffer on a Uint8Array (fszoo/index.js:35),
which this branch lowers; its first deferred refusal is the existing
SC1101 for a closure passed into an unknown slot (fszoo/index.js:44), so
the expectation records SC1101.
The branch's new corpus programs (1112 and 6200 to 6210) get per-program
cost files in tests/harness/corpus-costs, taken from the differential and
llvm-differential case durations in this branch's Linux CI shards.
Chris Tate