A top-level require binding that earlier code could reach was refused
(SC1013). The reachability scan now follows Node's evaluation order:
hoisted functions and classes run only when reachable code names them, a
class statement runs only its heritage, computed keys, decorators and
static initializers, timer and promise callbacks run after the module
body, and publishing a value through module.exports, exports.n,
Object.defineProperty(exports, ...) or F.prototype.m runs nothing until
reachable code reads it back. This admits the export-first layouts of
semver, glob@7, fs.realpath, on-finished, readable-stream and
tsc-emitted CommonJS.
A const or let binding that code can still reach before its require now
compiles with an initialization flag set right after the require and a
module.tdzCheck before the outermost expression of every reference that
can run earlier, so an early read throws Node's ReferenceError before
any argument evaluates. A reference whose lowering leaves no expression
to check, a var binding (Node reads undefined there) and createRequire
bindings keep SC1013.
require() of a JSON document now answers one parsed object per document,
created in the requiring module's %init prelude unless another module
already created it, so repeated requires return the same object and
mutations are visible to every requirer. Require bindings of JSON
documents are ordinary storage, so destructuring (nested patterns,
defaults, missing keys) copies at the require as in Node.
Nested destructuring of a builtin require binds the members of the
sub-module the key names (const { types: { isPromise } } =
require('util')).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Compiler caches keyed by programs and lowering passes move onto the
objects that own their lifetime, and the field-creation pass recognizes
its own writes by their receiver temporaries. A source test keeps weak
collections out of the compiler. Records and arrays that reach an
untyped slot through a union now keep their identity, and empty object
literals are keyed by their native object, so both work as WeakMap and
WeakSet keys instead of failing at runtime.
- Share native parsing, declaration projection, and npm capability analysis through explicit frontend services.
- Scope module analysis caches and parser connections to their owning program lifecycle.
- Preserve global fetch reads in destructuring defaults across embedded npm modules.
