[cramforce]

Key weak collections by net sockets and servers, and carry the socket in undici client diagnostics

Summary

• WeakMap and WeakSet keys. net.Socket and net.Server values can now key weak collections by identity. Before, they failed at run time with "Weak collection keys of this native reference type have no weak lifetime lowering". Releasing a socket or server notifies the weak-dispose hook, so its entries go away with it. The hook is set only in programs that create a weak collection, so other net programs pay one predictable branch per release.
• Handles inside messages. A record holding a runtime handle, such as a socket in a diagnostics_channel message, now converts to a checked-dynamic value, with the handle boxed by reference. A bare handle already converted this way. Before, publishing { socket } was refused at compile time.
• undici client diagnostics. The built-in undici publishes socket on undici:client:connected and undici:client:sendHeaders. It is the same socket the connector returned. It also publishes connector on beforeConnect, connected and connectError, matching undici 5 and 7. As in undici, connectError carries no socket.

Evidence

Each program runs under Node and as a native binary, and the outputs must match.

• Corpus 6620-weak-keys-net-sockets covers:
  • WeakMap and WeakSet keyed by client sockets, server-side sockets and a server;
  • the same socket read back out of a published message;
  • delete;
  • the TypeError for a primitive key.
• npm cases undici5 and undici7 subscribe to the client channels and key a WeakMap<Socket, …> by each message's socket. Both under Node and natively, 12 messages carry the socket the wrapped connector returned and none carries another.
• The sanitized lane passes the new program and both undici cases. Lint and format are clean, and there is one new ts7 baseline.

Zero cost

Zero-cost gate against the base (3,498 programs: bench, self and the whole corpus):

• IR and LLVM are identical for every program, including the self-compile.
• The gate flagged one IR change, in fs-extra-package. That program compiles to identical IR, LLVM and executable when built directly from both trees, so the flag was build nondeterminism.
• Executable-only differences:
  • 133 net programs grow inside the socket and server release functions (the dispose branch);
  • 27 programs that link the weak-key check have a byte-level difference in it;
  • 1 program differs in a few bytes of scr_cyc_thread.
• Run time: bench geomean -0.27% and self +0.03%, both within tolerance.

🤖 Generated with Claude Code

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Project	Deployment	Actions	Updated
scriptc	Ready	Preview, v0	Oct 22, 2026 3:07am UTC