/**
 * test/desktop/shell.test.ts — unit tests for defaultShellForPlatform (B1).
 *
 * Covers every platform branch, with and without env.SHELL set.
 */

import { describe, test, expect } from 'vitest'
import { defaultShellForPlatform } from '../../desktop/src/shell.js'

describe('defaultShellForPlatform', () => {
  test('returns powershell.exe on win32 regardless of env.SHELL', () => {
    // Arrange / Act / Assert
    expect(defaultShellForPlatform('win32', {})).toBe('powershell.exe')
    expect(defaultShellForPlatform('win32', { SHELL: '/bin/zsh' })).toBe('powershell.exe')
  })

  test('returns env.SHELL on darwin when it is set', () => {
    // Arrange
    const env = { SHELL: '/opt/homebrew/bin/fish' }

    // Act
    const result = defaultShellForPlatform('darwin', env)

    // Assert
    expect(result).toBe('/opt/homebrew/bin/fish')
  })

  test('falls back to /bin/zsh on darwin when env.SHELL is unset', () => {
    expect(defaultShellForPlatform('darwin', {})).toBe('/bin/zsh')
  })

  test('returns env.SHELL on linux when it is set', () => {
    expect(defaultShellForPlatform('linux', { SHELL: '/usr/bin/bash' })).toBe('/usr/bin/bash')
  })

  test('falls back to /bin/bash on linux when env.SHELL is unset', () => {
    expect(defaultShellForPlatform('linux', {})).toBe('/bin/bash')
  })
})