runtime: propagate ReferenceError, Symbol, BigInt, and ToPrimitive errors through addition

[andrewtdiz]

Summary

Abrupt completions from operand GetValue, ToPrimitive, Symbol-to-string, and mixed BigInt/Number addition propagate as the same error Node/Test262 expects.

Affected Test262 rows

• SIGTRAP crash when a program mixes Buffer-typed and Uint8Array-typed function parameters #169 language/expressions/addition/S11.6.1_A2.1_T2.js (runtime-fail: Uncaught exception: Support custom menu bar items #1.2: x + 1 throw ReferenceError. Actual: Test262Error: Support custom menu bar items #1.1: x + 1 throw ReferenceError. Actual: 1)
• perf(runtime): eliminate heap allocation in parseFloat; fix Infinity (#92) #170 language/expressions/addition/S11.6.1_A2.1_T3.js (runtime-fail: Uncaught exception: Support custom menu bar items #1.2: 1 + y throw ReferenceError. Actual: Test262Error: Support custom menu bar items #1.1: 1 + y throw ReferenceError. Actual: 1)
• Add integration test for Fastify server.listen() #174 language/expressions/addition/S11.6.1_A2.3_T1.js (runtime-fail: Uncaught exception: Support custom menu bar items #1.3: var x = { valueOf: function () { throw "x"; } }; var y = { valueOf: function () { throw "y"; } }; x + y throw "x". Actual: Test262Error: Support custom menu bar items #1.1: var x = { valueOf: function () { throw "x"; } }; var y = { valueOf: function () { throw "y"; } }; x + y throw "x". Actual: NaN)
• Wire codegen dispatch for perry/i18n format wrappers (Currency, Percent, FormatNumber, ShortDate, LongDate, FormatTime, Raw) #188 language/expressions/addition/bigint-and-number.js (runtime-fail: TypeError: Cannot read properties of undefined (reading 'name'))
• Wire TS-callable codegen dispatch for perry/plugin (21 runtime FFI functions currently unreachable from user code) #189 language/expressions/addition/symbol-to-string.js (runtime-fail: Uncaught exception: Expected a to be thrown but no exception was thrown at all)
• Wire Canvas widget into the LLVM codegen (currently web/wasm only) #190 language/expressions/addition/order-of-evaluation.js (runtime-fail: Uncaught exception: ?GetValue(lhs) throws. Expected a MyError but got a undefined)

Perry actual behavior from report

• 1 x runtime-fail: TypeError: Cannot read properties of undefined (reading 'name')
• 1 x runtime-fail: Uncaught exception: ?GetValue(lhs) throws. Expected a MyError but got a undefined
• 1 x runtime-fail: Uncaught exception: Support custom menu bar items #1.2: 1 + y throw ReferenceError. Actual: Test262Error: Support custom menu bar items #1.1: 1 + y throw ReferenceError. Actual: 1
• 1 x runtime-fail: Uncaught exception: Support custom menu bar items #1.2: x + 1 throw ReferenceError. Actual: Test262Error: Support custom menu bar items #1.1: x + 1 throw ReferenceError. Actual: 1
• 1 x runtime-fail: Uncaught exception: Support custom menu bar items #1.3: var x = { valueOf: function () { throw "x"; } }; var y = { valueOf: function () { throw "y"; } }; x + y throw "x". Actual: Test262Error: Support custom menu bar items #1.1: var x = { valueOf: function () { throw "x"; } }; var y = { valueOf: function () { throw "y"; } }; x + y throw "x". Actual: NaN
• 1 x runtime-fail: Uncaught exception: Expected a to be thrown but no exception was thrown at all

Node / ECMAScript expected behavior

Abrupt completions from operand GetValue, ToPrimitive, Symbol-to-string, and mixed BigInt/Number addition propagate as the same error Node/Test262 expects.

Likely subsystem

runtime completion records / error construction / operator lowering

Acceptance criteria

• ReferenceError and user-thrown values are not swallowed or replaced by computed numeric results.
• Symbol and BigInt/Number addition throw the expected TypeError shape.
• The affected rows report the expected thrown constructor/value under Test262.

Validation

Run the Test262 differential against the affected area and confirm these rows leave the gap report:

scripts/test262_subset.py --root vendor/test262 --dir language/expressions/addition --sample-cap 99999 --report /tmp/COERCION_ERROR_PROP.json

This is Perry language/runtime semantics triage, not a Node core API compatibility issue.

[proggeramlug]

Verified resolved against current main (built fresh from origin/main, 207 commits ahead of an older checkout) and compared byte-for-byte to node --experimental-strip-types. Addition error propagation matches node: undeclared-reference ReferenceError on either operand, valueOf-throw propagation, BigInt plus number TypeError, Symbol TypeError, and GetValue(lhs)-before-rhs ordering. Closing as resolved.