deepseek-harness/packages/sandbox/sandbox-windows-acl/tests/failure-paths.spec.ts

/**
 * Failure-path unit tests with minimal stub binding tables: the spawn
 * helpers must close every handle they created before throwing, and
 * getTempPath must refuse to decode a buffer GetTempPathW never wrote.
 * Pure stubs — no real Win32 calls, so these run on every platform.
 */

import { describe, expect, it, vi } from 'vitest'
import koffi from 'koffi'

import { PROCESS_INFORMATION, getTempPath } from '../src/ffi.ts'
import type { NativePtr, Win32Bindings } from '../src/ffi.ts'
import { Win32Error } from '../src/errors.ts'
import { spawnSandboxed, spawnSandboxedInherited } from '../src/spawn.ts'

const PVOID = koffi.pointer('void')

/** The stub the CreateProcessAsUserW failure branch needs: pipes "succeed", the spawn fails with Win32 5. */
function pipeFailureApi(): { api: Win32Bindings; closed: bigint[]; closeHandle: ReturnType<typeof vi.fn> } {
  const closed: bigint[] = []
  let next = 1n
  const closeHandle = vi.fn((handle: NativePtr) => {
    closed.push(handle)
    return 1
  })
  const api = {
    createPipe: vi.fn((readSlot: NativePtr, writeSlot: NativePtr) => {
      koffi.encode(readSlot, PVOID, next++)
      koffi.encode(writeSlot, PVOID, next++)
      return 1
    }),
    setHandleInformation: vi.fn(() => 1),
    createProcessAsUserW: vi.fn(() => 0),
    getLastError: vi.fn(() => 5), // ERROR_ACCESS_DENIED: the failure the branch reports
    closeHandle,
    formatMessageW: vi.fn(() => 0),
  } as unknown as Win32Bindings
  return { api, closed, closeHandle }
}

/** The stub the ResumeThread failure branch needs: everything succeeds until ResumeThread returns 0xFFFFFFFF. */
function resumeFailureApi(): { api: Win32Bindings; closed: bigint[]; closeHandle: ReturnType<typeof vi.fn> } {
  const closed: bigint[] = []
  let std = 50n
  const closeHandle = vi.fn((handle: NativePtr) => {
    closed.push(handle)
    return 1
  })
  const api = {
    createJobObjectW: vi.fn(() => 100n),
    setInformationJobObject: vi.fn(() => 1),
    getStdHandle: vi.fn(() => std++),
    setHandleInformation: vi.fn(() => 1),
    createProcessAsUserW: vi.fn((
      _token: unknown, _app: unknown, _cmd: unknown, _pa: unknown, _ta: unknown,
      _inherit: unknown, _flags: unknown, _env: unknown, _cwd: unknown, _si: unknown, processInfo: NativePtr,
    ) => {
      koffi.encode(processInfo, PROCESS_INFORMATION, { hProcess: 200n, hThread: 201n, dwProcessId: 1234, dwThreadId: 5678 })
      return 1
    }),
    assignProcessToJobObject: vi.fn(() => 1),
    resumeThread: vi.fn(() => 0xFFFFFFFF),
    getLastError: vi.fn(() => 5),
    closeHandle,
    formatMessageW: vi.fn(() => 0),
  } as unknown as Win32Bindings
  return { api, closed, closeHandle }
}

describe('spawn failure paths close their handles', () => {
  // A dummy token value; the stubbed spawn never reads it.
  const token = 1n as NativePtr

  it('spawnSandboxed closes all six pipe handles before throwing when CreateProcessAsUserW fails', () => {
    const { api, closed, closeHandle } = pipeFailureApi()
    let caught: unknown
    try {
      spawnSandboxed(api, token, { command: 'probe.exe', args: [], cwd: 'C:\\' })
    } catch (error) {
      caught = error
    }
    expect(caught).toBeInstanceOf(Win32Error)
    expect((caught as Win32Error).api).toBe('CreateProcessAsUserW')
    expect((caught as Win32Error).win32Code).toBe(5)
    expect(closeHandle).toHaveBeenCalledTimes(6)
    expect(closed).toEqual([1n, 2n, 3n, 4n, 5n, 6n])
  })

  it('spawnSandboxedInherited closes thread, process, and kill-on-close job before throwing when ResumeThread fails', () => {
    const { api, closed, closeHandle } = resumeFailureApi()
    let caught: unknown
    try {
      spawnSandboxedInherited(api, token, { command: 'probe.exe', args: [], cwd: 'C:\\' })
    } catch (error) {
      caught = error
    }
    expect(caught).toBeInstanceOf(Win32Error)
    expect((caught as Win32Error).api).toBe('ResumeThread')
    expect((caught as Win32Error).win32Code).toBe(5)
    // thread, process, job — closing the job triggers kill-on-close so the
    // suspended child dies instead of hanging until this process exits.
    expect(closeHandle).toHaveBeenCalledTimes(3)
    expect(closed).toEqual([201n, 200n, 100n])
  })
})

describe('getTempPath buffer defense', () => {
  it('throws a clear error instead of decoding a buffer GetTempPathW never wrote', () => {
    const api = { getTempPathW: vi.fn(() => 300) } as unknown as Win32Bindings // 300 > the 261-char buffer
    expect(() => getTempPath(api)).toThrow(/GetTempPathW failed \(Win32 122\): required 300/u)
  })
})