[cramforce]

Stacked on #1903. Seventh of nine Node islands PRs.

What it does

• Fences make islands. Runtime and object-model fences (by the NI-2 report class) and module-init fences pick islands. If the island build fails, the build retries with only the packages whose fences surely fire. If that also fails, the native build carries SC8023 naming the packages and the island build's first error, instead of silently keeping a build that dies at module init. --npm-static=<pkg> keeps a package native. A failed lowering retries with the report-marked packages as islands.
• A native package requiring an island package. Top-level const x = require("<island>") in a compiled module binds module.exports.
• Routing follows the value. The nodeIsland.get/set/invoke/apply/construct adapters take the checked-dynamic path when the receiver is not an island handle. Examples: a native object typed by an island interface, or a native error in an island .catch. scr_dyn_invoke.c is now linked for island programs.
• Object literals with spreads, methods, accessors or computed keys cross by reference. string | Buffer reads count as copies, and .toString("utf8") on that union is lowered. CommonJS namespace members are snapshotted.
• util.types.* and Array.isArray answer for island values.
• Uncaught island errors print Node's report: the source line and arrow (from Exception::CreateMessage), the stack and Node.js v<version>. This adds ErrorInfo.arrow, bridge ABI 9. The error is released after the report.
• Severity: SC8020 renders as a warning, and SC8001/SC8021 as notes. Pure CommonJS helper packages are duplicated without a warning.
• util.types is released at exit (RC audit).

Evidence

• Corpus programs, byte-identical with Node:
  • 6818-node-island-mixed: a native importer, island interfaces on native objects, spread and method options, string|Buffer, a .catch read.
  • 6819-node-island-fenced: an esbuild getter prologue as an auto island.
  • 6825-node-island-init-fence: a module-init fence that picks an island; with --node-islands=off the program dies at init.
  • 6826-node-island-undefined-args: undefined arguments and fields, native number[], ?. on island-typed native objects, cwd and env changed natively.
• npm harness: about fifteen cases that were deferred refusals now run as islands and match Node. Examples: misc-shims, node24-deep-equality, node24-env, node24-mime(-errors), node24-parseargs, node24-util-types, stream-shims, util-shims, bytes-exit, dotfolder, fetch-destructure, node24-esm-metadata. Island stderr now compares exactly, except that each run of stack frames is cut to the frames Node and native share.

Note on jose

The report-class rule picks jose (6331), run-node (6610) and fs.realpath (6570) as islands, because each has object-model markers and some fences. 6331 and 6610 then differ from Node; 6570 matches. This contradicts the decision that jose stays native. Those two corpus programs now pin their packages with "native" in a corpus package.json. A follow-up should decide the default: per-function reachability, or no report-class rule for builds that succeed natively.

Known shortcut

• hot-shots-udp is now picked as an island (it has runtime fences), and it diverges: output stops after the socket-not-running error. It is marked as a known divergence. Compile chalk 5 and hot-shots 8 from built-in shims with callable class instances #1836's built-in hot-shots shim compiles the package natively, and that PR should drop the mark.
• instanceof <native builtin class> and Buffer.isBuffer on island handles are not mapped.

Gate results

• Island set in a Vercel Sandbox, with the libnode dev pack rebuilt from this branch's bridge (node-island*.test.ts, npm.test.ts, packages/compiler/src/node-islands, differential 68xx): plain 223/223 + diff 68/68; sanitized 222/223 (node24-deep-equality exits 1 at exit, the TLS exit race that Exit cleanly with Node loaded and keep nested entries on Node's stack (NI-7c, NI-3b) #1905 fixes) + 68/68.
• pnpm lint, pnpm format:check and pnpm test:ts7 --baselines-only pass.
• The self-hosted compiler (packages/compiler/src/native/cli.ts --emit=llvm) builds.
• Zero-cost gate: 2835 identical. The DIFFERS is the same nondeterministic corpus/fs-extra-package. Three npm corpus programs change by design under auto routing: 6331 (jose) and 6610 (run-node) are pinned native in their corpus package.json on this branch and stay identical, and 6570 (fs.realpath) now runs as an island and matches Node.

CI on the first push found failures outside the focused island set: the ABI in bridge.test.ts, the runtime ABI header declarations, the effect gate on the ts7 allowlist, weak collections in the compiler, the pipeline scout and the Node version line. The fixes are folded into the PRs that introduce each piece, and they are re-checked in a Sandbox on the final tree.

Stack

#1898
#1899
#1900
#1901
#1902
#1903
→ #1904
#1905
#1906
#1907
#1908

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Project	Deployment	Actions	Updated
scriptc	Ready	Preview, v0	Oct 27, 2026 12:43pm UTC