fix: preserve unicode in Windows clipboard fallback (#388)

* fix: preserve unicode in Windows clipboard fallback

* fix: avoid Windows clipboard stdin codepage issues

* test: fix Windows clipboard temp path fixture

src/ink/termio/osc.test.ts

@@ -0,0 +1,134 @@
+import { afterEach, beforeEach, describe, expect, mock, test } from 'bun:test'
+import { join } from 'node:path'
+
+const originalEnv = { ...process.env }
+const originalPlatform = process.platform
+const mockedClipboardPath = join(process.cwd(), 'openclaude-clipboard.txt')
+
+const generateTempFilePathMock = mock(() => mockedClipboardPath)
+
+const execFileNoThrowMock = mock(
+  async () => ({ code: 0, stdout: '', stderr: '' }),
+)
+
+mock.module('../../utils/execFileNoThrow.js', () => ({
+  execFileNoThrow: execFileNoThrowMock,
+}))
+
+mock.module('../../utils/tempfile.js', () => ({
+  generateTempFilePath: generateTempFilePathMock,
+}))
+
+async function importFreshOscModule() {
+  return import(`./osc.ts?ts=${Date.now()}-${Math.random()}`)
+}
+
+async function flushClipboardCopy(): Promise<void> {
+  await new Promise(resolve => setTimeout(resolve, 0))
+}
+
+describe('Windows clipboard fallback', () => {
+  beforeEach(() => {
+    execFileNoThrowMock.mockClear()
+    generateTempFilePathMock.mockClear()
+    process.env = { ...originalEnv }
+    delete process.env['SSH_CONNECTION']
+    delete process.env['TMUX']
+    Object.defineProperty(process, 'platform', { value: 'win32' })
+  })
+
+  afterEach(() => {
+    process.env = { ...originalEnv }
+    Object.defineProperty(process, 'platform', { value: originalPlatform })
+  })
+
+  test('uses PowerShell instead of clip.exe for local Windows copy', async () => {
+    const { setClipboard } = await importFreshOscModule()
+
+    await setClipboard('Привет мир')
+    await flushClipboardCopy()
+
+    expect(execFileNoThrowMock.mock.calls.some(([cmd]) => cmd === 'clip')).toBe(
+      false,
+    )
+    expect(
+      execFileNoThrowMock.mock.calls.some(([cmd]) => cmd === 'powershell'),
+    ).toBe(true)
+  })
+
+  test('passes Windows clipboard text through a UTF-8 temp file instead of stdin', async () => {
+    const { setClipboard } = await importFreshOscModule()
+
+    await setClipboard('Привет мир')
+    await flushClipboardCopy()
+
+    const windowsCall = execFileNoThrowMock.mock.calls.find(
+      ([cmd]) => cmd === 'powershell',
+    )
+
+    expect(windowsCall?.[2]).toMatchObject({
+      stdin: 'ignore',
+    })
+    expect(windowsCall?.[2]).not.toMatchObject({ input: 'Привет мир' })
+    expect(windowsCall?.[2]).not.toMatchObject({
+      env: expect.objectContaining({
+        OPENCLAUDE_CLIPBOARD_TEXT_B64: expect.any(String),
+      }),
+    })
+    expect(windowsCall?.[1]).toContain(
+      `$text = [System.IO.File]::ReadAllText('${mockedClipboardPath.replace(/'/g, "''")}', [System.Text.Encoding]::UTF8); Set-Clipboard -Value $text`,
+    )
+  })
+})
+
+describe('clipboard path behavior remains stable', () => {
+  beforeEach(() => {
+    execFileNoThrowMock.mockClear()
+    process.env = { ...originalEnv }
+    delete process.env['SSH_CONNECTION']
+    delete process.env['TMUX']
+  })
+
+  afterEach(() => {
+    process.env = { ...originalEnv }
+    Object.defineProperty(process, 'platform', { value: originalPlatform })
+  })
+
+  test('getClipboardPath stays native on local macOS', async () => {
+    Object.defineProperty(process, 'platform', { value: 'darwin' })
+    const { getClipboardPath } = await importFreshOscModule()
+
+    expect(getClipboardPath()).toBe('native')
+  })
+
+  test('getClipboardPath stays tmux-buffer when TMUX is set', async () => {
+    Object.defineProperty(process, 'platform', { value: 'linux' })
+    process.env['TMUX'] = '/tmp/tmux-1000/default,123,0'
+    const { getClipboardPath } = await importFreshOscModule()
+
+    expect(getClipboardPath()).toBe('tmux-buffer')
+  })
+
+  test('Windows clipboard fallback is skipped over SSH', async () => {
+    Object.defineProperty(process, 'platform', { value: 'win32' })
+    process.env['SSH_CONNECTION'] = '1 2 3 4'
+    const { setClipboard } = await importFreshOscModule()
+
+    await setClipboard('Привет мир')
+
+    expect(execFileNoThrowMock.mock.calls.some(([cmd]) => cmd === 'powershell')).toBe(
+      false,
+    )
+  })
+
+  test('local macOS clipboard fallback still uses pbcopy', async () => {
+    Object.defineProperty(process, 'platform', { value: 'darwin' })
+    const { setClipboard } = await importFreshOscModule()
+
+    await setClipboard('hello')
+
+    expect(execFileNoThrowMock.mock.calls.some(([cmd]) => cmd === 'pbcopy')).toBe(
+      true,
+    )
+  })
+})