test: cover user enumeration failures

src/users.spec.ts

@@ -0,0 +1,63 @@
+import { execSync } from 'node:child_process'
+
+import { beforeEach, describe, expect, it, type Mock, vi } from 'vitest'
+
+vi.mock('node:child_process', () => ({
+  execSync: vi.fn(),
+}))
+
+vi.mock('node:fs', () => ({
+  readdirSync: vi.fn(),
+}))
+
+vi.mock('./logger.js', () => ({
+  log: { error: vi.fn(), info: vi.fn(), warn: vi.fn() },
+}))
+
+vi.mock('./platform.js', () => ({
+  getPlatform: vi.fn(),
+}))
+
+import { getPlatform } from './platform.js'
+import { enumerateUsers } from './users'
+
+const mockExecSync = execSync as Mock
+const mockGetPlatform = getPlatform as Mock
+
+beforeEach(() => {
+  vi.clearAllMocks()
+})
+
+describe('enumerateUsers failure behavior', () => {
+  it('throws when the macOS user list command fails', () => {
+    mockGetPlatform.mockReturnValue('darwin')
+    mockExecSync.mockImplementation((command: string) => {
+      if (command === 'dscl . -list /Users UniqueID') throw new Error('dscl failed')
+      return ''
+    })
+
+    expect(() => enumerateUsers()).toThrow('dscl failed')
+  })
+
+  it('throws when the Linux passwd lookup fails', () => {
+    mockGetPlatform.mockReturnValue('linux')
+    mockExecSync.mockImplementation((command: string) => {
+      if (command === 'getent passwd') throw new Error('getent failed')
+      return ''
+    })
+
+    expect(() => enumerateUsers()).toThrow('getent failed')
+  })
+
+  it('skips a macOS user when PrimaryGroupID cannot be read', () => {
+    mockGetPlatform.mockReturnValue('darwin')
+    mockExecSync.mockImplementation((command: string) => {
+      if (command === 'dscl . -list /Users UniqueID') return 'alice 501\n'
+      if (command === 'dscl . -read /Users/alice NFSHomeDirectory') return 'NFSHomeDirectory: /Users/alice\n'
+      if (command === 'dscl . -read /Users/alice PrimaryGroupID') throw new Error('gid failed')
+      throw new Error(`unexpected command: ${command}`)
+    })
+
+    expect(enumerateUsers()).toEqual([])
+  })
+})