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Malte UblandClaude Opus 5.5
48d524a321
D-2: Node resolves a name nothing declares at run time, and the read always
throws the catchable `ReferenceError: x is not defined` at the access. A
`.js` read of such a name now compiles to exactly that throw instead of
refusing the program, with Node's message and Node's catchability.
The read's value is checked-dynamic (the checker's error-any after the
relaxation in the previous commit, narrowed by the use site where one
provides context), and every path through it unwinds before a use observes
the value, so the dynamic slot never carries a wrong value. Shorthand
position (`{ x }`) needs its own declaration test: there the checker
answers the PROPERTY symbol, so the name is bound when
`getShorthandAssignmentValueSymbol` has no value for it.
`typeof` is the one operator that never touches its operand value, and Node
answers "undefined" for an undeclared name, so `lowerDynTypeofTest` folds
the test to a literal before the read is ever lowered — `typeof x ===
"undefined"` stays true and `typeof x` alone prints "undefined".
No name that Node serves from the global object reaches this branch: the
compiler models those as declared (that is how the corpus reads `process`,
`console` and friends), so this is the name Node itself would report
missing.
The corpus program pins every shape: bare read, call, member read,
arithmetic, comparison, shorthand, destructuring default, typeof test, a
guarded read that keeps running after the throw, and a declared control.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>