vfs: add --vfs-load to run modules from a mount - #8
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Builds on --vfs-mount to make a mount a real execution environment, resolving require()/import inside it. Adds --vfs-load, which runs the entry point (process.argv[1]) and all subsequent require()/import resolution against the last --vfs-mount rather than the real file system. process.argv[1] becomes that mount's root, as if `node <mountPoint>` had been run, so the mount's own package.json "main"/index.js selects the entry point and positional arguments are the program's own. A self-mounting shebang (`#!/usr/bin/env -S node --vfs-load --vfs-mount`) therefore makes an archive directly executable. --vfs-load requires at least one --vfs-mount, and workers inherit it alongside the mounts. Making resolution VFS-aware requires four of the CJS/ESM loader's resolution primitives - package.json reading, nearest-parent/scope lookup, legacy main resolution, and extensionless-file format sniffing - to stop bypassing the public fs module and call it instead, since that bypass is what let them ignore a mount. Each defers to the real native binding unchanged for anything outside an active mount. A lean mount registry (internal/vfs/registry) is extracted from internal/vfs/setup so the resolution fast path can answer "is this path under a mount?" without loading the heavier setup/provider machinery. Provider selection - and, for a --vfs-load entry, its resolution - is deferred until after -r and --import preload modules have run, so a provider registered from either backs the mount. Native addons are supported: a directory-backed mount dlopens the real underlying file directly (RealFSProvider.toRealPath); an archive-backed mount extracts the addon to a content-hashed temp file first, scoped per pid so processes don't clobber each other's extractions. Signed-off-by: Philipp Dunkel <pip@pipobscure.com>
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Builds on --vfs-mount to make a mount a real execution environment, resolving require()/import inside it.
Adds --vfs-load, which runs the entry point (process.argv[1]) and all subsequent require()/import resolution against the last --vfs-mount rather than the real file system. process.argv[1] becomes that mount's root, as if
node <mountPoint>had been run, so the mount's own package.json "main"/index.js selects the entry point and positional arguments are the program's own. A self-mounting shebang (#!/usr/bin/env -S node --vfs-load --vfs-mount) therefore makes an archive directly executable. --vfs-load requires at least one --vfs-mount, and workers inherit it alongside the mounts.Making resolution VFS-aware requires four of the CJS/ESM loader's resolution primitives - package.json reading, nearest-parent/scope lookup, legacy main resolution, and extensionless-file format sniffing - to stop bypassing the public fs module and call it instead, since that bypass is what let them ignore a mount. Each defers to the real native binding unchanged for anything outside an active mount. A lean mount registry (internal/vfs/registry) is extracted from internal/vfs/setup so the resolution fast path can answer "is this path under a mount?" without loading the heavier setup/provider machinery.
Provider selection - and, for a --vfs-load entry, its resolution - is deferred until after -r and --import preload modules have run, so a provider registered from either backs the mount.
Native addons are supported: a directory-backed mount dlopens the real underlying file directly (RealFSProvider.toRealPath); an archive-backed mount extracts the addon to a content-hashed temp file first, scoped per pid so processes don't clobber each other's extractions.