TUI clipboard CJK/UTF-8 encoding fixes for PowerShell/WSL2

Fixes on record

Merged to main. A stamp counts the issues a fix is linked to.

• #35222 fix(tui): preserve UTF-8 in PowerShell clipboard writes (CJK/emoji)

  merged to main

  files: ui-tui/src/__tests__/clipboard.test.ts, ui-tui/src/lib/clipboard.ts

  Show the diff

  • ui-tui/src/__tests__/clipboard.test.ts

    @@ -269,7 +269,14 @@ describe('writeClipboardText', () => {
           expect.arrayContaining(['-NoProfile', '-NonInteractive']),
           expect.anything()
         )
    -    expect(stdin.end).toHaveBeenCalledWith('wsl text')
    +    // PowerShell uses base64-encoded UTF-8 via command argument, not stdin
    +    expect(stdin.end).not.toHaveBeenCalled()
    +    const calledArgs = start.mock.calls[0][1] as string[]
    +    const commandIdx = calledArgs.indexOf('-Command')
    +    expect(commandIdx).toBeGreaterThan(-1)
    +    const script = calledArgs[commandIdx + 1]
    +    expect(script).toContain('FromBase64String')
    +    expect(script).toContain(Buffer.from('wsl text', 'utf8').toString('base64'))
       })
     
       it('prefers the Windows clipboard path over wl-copy inside WSLg', async () => {
    @@ -300,7 +307,13 @@ describe('writeClipboardText', () => {
           expect.arrayContaining(['-NoProfile', '-NonInteractive']),
           expect.anything()
         )
    -    expect(stdin.end).toHaveBeenCalledWith('wslg text')
    +    // PowerShell uses base64-encoded UTF-8 via command argument, not stdin
    +    expect(stdin.end).not.toHaveBeenCalled()
    +    const calledArgs = start.mock.calls[0][1] as string[]
    +    const commandIdx = calledArgs.indexOf('-Command')
    +    const script = calledArgs[commandIdx + 1]
    +    expect(script).toContain('FromBase64String')
    +    expect(script).toContain(Buffer.from('wslg text', 'utf8').toString('base64'))
       })
     
       it('uses PowerShell on Windows', async () => {
    @@ -325,5 +338,32 @@ describe('writeClipboardText', () => {
           expect.arrayContaining(['-NoProfile', '-NonInteractive']),
           expect.anything()
         )
    +    // PowerShell uses base64-encoded UTF-8 via command argument, not stdin
    +    expect(stdin.end).not.toHaveBeenCalled()
    +  })
    +
    +  it('preserves CJK text via base64 encoding in PowerShell on WSL', async () => {
    +    const stdin = { end: vi.fn() }
    +
    +    const child = {
    +      once: vi.fn((event: string, cb: (code?: number) => void) => {
    +        if (event === 'close') {
    +          cb(0)
    +        }
    +
    +        return child
    +      }),
    +      stdin
    +    }
    +
    +    const start = vi.fn().mockReturnValue(child)
    +    const cjkText = '你好世界，测试中文 🎉'
    +
    +    await expect(writeClipboardText(cjkText, 'linux', start as any, { WSL_INTEROP: '/tmp/socket' })).resolves.toBe(true)
    +    const calledArgs = start.mock.calls[0][1] as string[]
    +    const commandIdx = calledArgs.indexOf('-Command')
    +    const script = calledArgs[commandIdx + 1]
    +    expect(script).toContain(Buffer.from(cjkText, 'utf8').toString('base64'))
    +    expect(script).toContain('UTF8.GetString')
       })
     })

  • ui-tui/src/lib/clipboard.ts

    @@ -91,33 +91,42 @@ export async function readClipboardText(
       return null
     }
     
    +// PowerShell on Windows/WSL decodes piped stdin with the system ANSI code
    +// page (e.g. CP936), not UTF-8, so $input-based writes mangle CJK/emoji. We
    +// instead base64-encode the UTF-8 bytes and pass them as a -Command argument,
    +// decoding with UTF8.GetString — this removes the stdin-encoding variable
    +// entirely (also immune to BOM injection on redirect). PowerShell entries set
    +// stdin=false; every other backend reads UTF-8 stdin natively.
    +type WriteCmd = { args: readonly string[]; cmd: string; stdin: boolean }
    +
    +function _powershellWriteScript(b64: string): string {
    +  return `Set-Clipboard -Value ([System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String('${b64}')))`
    +}
    +
     function writeClipboardCommands(
       platform: NodeJS.Platform,
       env: NodeJS.ProcessEnv
    -): Array<{ args: readonly string[]; cmd: string }> {
    +): WriteCmd[] {
       if (platform === 'darwin') {
    -    return [{ cmd: 'pbcopy', args: [] }]
    +    return [{ cmd: 'pbcopy', args: [], stdin: true }]
       }
     
       if (platform === 'win32') {
    -    return [{ cmd: 'powershell', args: ['-NoProfile', '-NonInteractive', '-Command', 'Set-Clipboard -Value $input'] }]
    +    return [{ cmd: 'powershell', args: ['-NoProfile', '-NonInteractive'], stdin: false }]
       }
     
    -  const attempts: Array<{ args: readonly string[]; cmd: string }> = []
    +  const attempts: WriteCmd[] = []
     
       if (env.WSL_INTEROP || env.WSL_DISTRO_NAME) {
    -    attempts.push({
    -      cmd: 'powershell.exe',
    -      args: ['-NoProfile', '-NonInteractive', '-Command', 'Set-Clipboard -Value $input']
    -    })
    +    attempts.push({ cmd: 'powershell.exe', args: ['-NoProfile', '-NonInteractive'], stdin: false })
       }
     
       if (env.WAYLAND_DISPLAY) {
    -    attempts.push({ cmd: 'wl-copy', args: ['--type', 'text/plain'] })
    +    attempts.push({ cmd: 'wl-copy', args: ['--type', 'text/plain'], stdin: true })
       }
     
    -  attempts.push({ cmd: 'xclip', args: ['-selection', 'clipboard', '-in'] })
    -  attempts.push({ cmd: 'xsel', args: ['--clipboard', '--input'] })
    +  attempts.push({ cmd: 'xclip', args: ['-selection', 'clipboard', '-in'], stdin: true })
    +  attempts.push({ cmd: 'xsel', args: ['--clipboard', '--input'], stdin: true })
     
       return attempts
     }
    @@ -144,14 +153,21 @@ export async function writeClipboardText(
     ): Promise<boolean> {
       const candidates = writeClipboardCommands(platform, env)
     
    -  for (const { cmd, args } of candidates) {
    +  for (const cmdEntry of candidates) {
         try {
           const ok = await new Promise<boolean>(resolve => {
    -        const child = start(cmd, [...args], { stdio: ['pipe', 'ignore', 'ignore'], windowsHide: true })
    -
    -        child.once('error', () => resolve(false))
    -        child.once('close', code => resolve(code === 0))
    -        child.stdin?.end(text)
    +        if (cmdEntry.stdin) {
    +          const child = start(cmdEntry.cmd, [...cmdEntry.args], { stdio: ['pipe', 'ignore', 'ignore'], windowsHide: true })
    +          child.once('error', () => resolve(false))
    +          child.once('close', (code: number | null) => resolve(code === 0))
    +          child.stdin?.end(text)
    +        } else {
    +          const b64 = Buffer.from(text, 'utf8').toString('base64')
    +          const script = _powershellWriteScript(b64)
    +          const child = start(cmdEntry.cmd, [...cmdEntry.args, '-Command', script], { stdio: ['ignore', 'ignore', 'ignore'], windowsHide: true })
    +          child.once('error', () => resolve(false))
    +          child.once('close', (code: number | null) => resolve(code === 0))
    +        }
           })
     
           if (ok) {