Buy the grammar, own the execution: @yarnpkg/parsers parses the command
line - aliased at bundle time to its shell entry so the root barrel's
syml/js-yaml closure stays out of the worker - and a VFS-backed evaluator
with a coreutils command table runs it inside the worker host. Each shell
process is a real child WebWorker spawned from the same bundle (the first
frame decides the role), so the TERM-then-KILL ladder is real - TERM
requests, KILL terminates the worker - and the file face stays
asynchronous end to end, since the deployment target serves no COOP/COEP
headers and SharedArrayBuffer never exists there. node:child_process
reports through the ChildProcess surface the subprocess service consumes;
execSync, execFileSync and fork refuse, and node-pty stays stubbed.
Two private experimental packages run the whole harness tree inside one
dedicated Web Worker. dsh-experimental-webworker-runtime owns the in-memory
VFS (BigInt stats with per-path identity and strictly increasing mtimes),
the CommonJS wrapper loader over a lazily-evaluated builtin table whose
shims typecheck against Node's own module types, the postMessage tunnel
speaking plain HTTP, the AsyncLocalStorage runtime, and the worker
assembly. dsh-experimental-webworker-packer lowers every module body at
pack time against the shared wrapper contract, sweeps the profile closure
by static reachability, and writes a deterministically gzip-compressed tar
the worker inflates through the browser's native DecompressionStream while
it downloads.
imccyu