import { type InitialFiles, InMemoryFs, MountableFs, type MountableFsOptions } from 'just-bash' interface ExtendedMountableFsOptions extends Omit { readOnly?: boolean initialFiles?: InitialFiles | undefined } /** * Extends MountableFs with sync method proxying and optional read-only mode. * * MountableFs doesn't proxy sync methods to its base fs, so just-bash's * initFilesystem skips creating /bin, /tmp, /dev, etc. and registerCommand * can't write command stubs. This subclass exposes the base InMemoryFs's * sync methods so the full Unix directory structure is initialized. * * When readOnly is true, all async mutation methods throw EROFS. */ export class ExtendedMountableFs extends MountableFs { #base: InMemoryFs #readOnly: boolean #readFiles: Set = new Set() #readDirs: Set = new Set() #observing = false constructor(opts?: ExtendedMountableFsOptions) { const { readOnly, initialFiles, ...rest } = opts ?? {} const base = new InMemoryFs(initialFiles) super({ ...rest, base }) this.#base = base this.#readOnly = readOnly ?? false } /** Start observing file and directory reads. Clears any previous observations. */ startObservingReads(): void { this.#readFiles.clear() this.#readDirs.clear() this.#observing = true } /** Stop observing and return the collected file/dir reads. */ stopObservingReads(): { files: string[]; dirs: string[] } { this.#observing = false const result = { files: [...this.#readFiles], dirs: [...this.#readDirs] } this.#readFiles.clear() this.#readDirs.clear() return result } override async readFile( p: string, ...a: Parameters extends [string, ...infer R] ? R : never ) { if (this.#observing) this.#readFiles.add(p) return super.readFile(p, ...a) } override async readdir(p: string) { if (this.#observing) this.#readDirs.add(p) return super.readdir(p) } mkdirSync(path: string, options?: { recursive?: boolean }) { return this.#base.mkdirSync(path, options) } writeFileSync(path: string, content: string | Uint8Array) { return this.#base.writeFileSync(path, content) } #assertWritable(op: string): void { if (this.#readOnly) { throw new Error(`EROFS: read-only file system, ${op}`) } } override async writeFile( p: string, ...a: Parameters extends [string, ...infer R] ? R : never ) { this.#assertWritable(`write '${p}'`) return super.writeFile(p, ...a) } override async appendFile( p: string, ...a: Parameters extends [string, ...infer R] ? R : never ) { this.#assertWritable(`append '${p}'`) return super.appendFile(p, ...a) } override async mkdir( p: string, ...a: Parameters extends [string, ...infer R] ? R : never ) { this.#assertWritable(`mkdir '${p}'`) return super.mkdir(p, ...a) } override async rm( p: string, ...a: Parameters extends [string, ...infer R] ? R : never ) { this.#assertWritable(`rm '${p}'`) return super.rm(p, ...a) } override async chmod( p: string, ...a: Parameters extends [string, ...infer R] ? R : never ) { this.#assertWritable(`chmod '${p}'`) return super.chmod(p, ...a) } override async symlink(...a: Parameters) { this.#assertWritable(`symlink '${a[1]}'`) return super.symlink(...a) } override async link(...a: Parameters) { this.#assertWritable(`link '${a[1]}'`) return super.link(...a) } override async cp( _s: string, p: string, ...a: Parameters extends [string, string, ...infer R] ? R : never ) { this.#assertWritable(`cp '${p}'`) return super.cp(_s, p, ...a) } override async mv(...a: Parameters) { this.#assertWritable(`mv '${a[1]}'`) return super.mv(...a) } override async utimes( p: string, ...a: Parameters extends [string, ...infer R] ? R : never ) { this.#assertWritable(`utimes '${p}'`) return super.utimes(p, ...a) } }