fix(windows): prevent terminal startup failures

## Bug 详情
- issues.md #46：Windows MSYS2/UCRT64 下执行 csc，欢迎信息输出后在 stdin raw mode/终端输入初始化阶段崩溃，出现 native std::bad_weak_ptr 和后续 Bun mutex corrupt。
- issues.md #47：cmd.exe 可启动，但 PowerShell 运行 csc 会走 npm 生成的 csc.ps1；截图显示 node.exe 报错 "Input must be provided either through stdin or as a prompt argument when using --print"，说明裸 csc 被误判成 print/non-interactive 模式。

## 根因
- MSYS2/Cygwin/mintty 等 Windows 终端对 Node/Bun stdin raw mode 和终端扩展控制序列兼容性不稳定，启动早期强行 setRawMode/查询终端能力会触发崩溃风险。
- npm 的 PowerShell shim 解析优先级高于 csc.cmd，且可能让 stdout TTY 状态不可用；原 main.tsx 只要 stdout 非 TTY 就自动进入 non-interactive/--print 路径，最终在没有 prompt/stdin 时触发 #47 的报错。

## 修复方案
- 为 Ink stdin raw mode 增加 Windows 风险终端检测，在 MSYS2/Cygwin/mintty 或显式禁用开关下跳过 raw mode，使用 cooked input fallback。
- early input 捕获在启动早期复用同类风险判断，避免 REPL 渲染前就触发 raw mode 崩溃。
- postinstall 在 Windows 上清理属于本包的 csc.ps1，让 PowerShell 回落到与 cmd.exe 一致的 csc.cmd 启动路径。
- 新增 non-interactive 判定工具，保留显式 -p/--print、--init-only、--sdk-url 的 headless 行为，但要求 stdin/stdout 都不是交互 TTY 才自动进入 non-interactive，避免 PowerShell shim 下裸 csc 被误判。

## 变更要点
- 新增 packages/@ant/ink/src/core/raw-mode-support.ts 及单元测试，覆盖普通 Windows shell、MSYS2/Cygwin/mintty 和禁用开关
- 调整 Ink App raw mode 生命周期，只在真正启用 raw mode 后写入/清理 bracketed paste、focus reporting、extended key 等终端控制序列
- 调整 component unmount/exit 清理逻辑，按 rawModeEnabledCount/rawModeActive 关闭实际启用的输入监听和 raw mode
- 调整 src/utils/earlyInput.ts，避免不安全 Windows 终端在启动阶段启用 stdin raw mode
- 调整 scripts/postinstall.cjs，立即和延迟清理 npm 生成的 csc.ps1 shim
- 调整 src/main.tsx 使用 shouldUseNonInteractiveSession，并新增对应测试覆盖 PowerShell shim 场景

## 自测
- bun test packages/@ant/ink/src/core/__tests__/raw-mode-support.test.ts src/utils/__tests__/earlyInput.test.ts src/utils/__tests__/nonInteractiveSession.test.ts
- node --check scripts/postinstall.cjs
- bun run src/entrypoints/cli.tsx --version
- bun run lint
- git diff --check

## 已知限制
- bun run typecheck 仍失败，错误来自仓库既有缺失声明/缺失模块和无关类型问题，不来自本次改动。

packages/@ant/ink/src/components/App.tsx

@@ -40,6 +40,7 @@ import {
   type ParsedMouse,
   parseMultipleKeypresses,
 } from '../core/parse-keypress.js';
+import { supportsStdinRawMode } from '../core/raw-mode-support.js';
 import reconciler from '../core/reconciler.js';
 import { finishSelection, hasSelection, type SelectionState, startSelection } from '../core/selection.js';
 import { isXtermJs, setXtversionName, supportsExtendedKeys } from '../core/terminal.js';
@@ -157,6 +158,7 @@ export default class App extends PureComponent<Props, State> {
   // Count how many components enabled raw mode to avoid disabling
   // raw mode until all components don't need it anymore
   rawModeEnabledCount = 0;
+  rawModeActive = false;
 
   internal_eventEmitter = new EventEmitter();
   keyParseState = INITIAL_STATE;
@@ -195,7 +197,11 @@ export default class App extends PureComponent<Props, State> {
 
   // Determines if TTY is supported on the provided stdin
   isRawModeSupported(): boolean {
-    return this.props.stdin.isTTY;
+    return supportsStdinRawMode(this.props.stdin);
+  }
+
+  isCookedModeFallbackSupported(): boolean {
+    return this.props.stdin.isTTY && !this.isRawModeSupported();
   }
 
   override render() {
@@ -258,7 +264,7 @@ export default class App extends PureComponent<Props, State> {
       this.pendingHyperlinkTimer = null;
     }
     // ignore calling setRawMode on an handle stdin it cannot be called
-    if (this.isRawModeSupported()) {
+    if (this.rawModeEnabledCount > 0) {
       this.handleSetRawMode(false);
     } else {
       // Even when raw mode was never enabled (e.g. non-TTY stdin on
@@ -279,7 +285,8 @@ export default class App extends PureComponent<Props, State> {
   handleSetRawMode = (isEnabled: boolean): void => {
     const { stdin } = this.props;
 
-    if (!this.isRawModeSupported()) {
+    const rawModeSupported = this.isRawModeSupported();
+    if (!rawModeSupported && !this.isCookedModeFallbackSupported()) {
       if (stdin === process.stdin) {
         throw new Error(
           'Raw mode is not supported on the current process.stdin, which Ink uses as input stream by default.\nRead about how to prevent this error on https://github.com/vadimdemedes/ink/#israwmodesupported',
@@ -314,39 +321,50 @@ export default class App extends PureComponent<Props, State> {
         }
 
         stdin.ref();
-        stdin.setRawMode(true);
-        stdin.addListener('readable', this.handleReadable);
-        // Enable bracketed paste mode
-        this.props.stdout.write(EBP);
-        // Enable terminal focus reporting (DECSET 1004)
-        this.props.stdout.write(EFE);
-        // Enable extended key reporting so ctrl+shift+<letter> is
-        // distinguishable from ctrl+<letter>. We write both the kitty stack
-        // push (CSI >1u) and xterm modifyOtherKeys level 2 (CSI >4;2m) —
-        // terminals honor whichever they implement (tmux only accepts the
-        // latter).
-        if (supportsExtendedKeys()) {
-          this.props.stdout.write(ENABLE_KITTY_KEYBOARD);
-          this.props.stdout.write(ENABLE_MODIFY_OTHER_KEYS);
+        if (rawModeSupported) {
+          stdin.setRawMode(true);
+          this.rawModeActive = true;
+        } else {
+          this.rawModeActive = false;
+          defaultCallbacks.logForDebugging(
+            '[stdin] Raw mode disabled for this Windows terminal; using cooked input fallback',
+            { level: 'warn' },
+          );
         }
-        // Probe terminal identity. XTVERSION survives SSH (query/reply goes
-        // through the pty), unlike TERM_PROGRAM. Used for wheel-scroll base
-        // detection when env vars are absent. Fire-and-forget: the DA1
-        // sentinel bounds the round-trip, and if the terminal ignores the
-        // query, flush() still resolves and name stays undefined.
-        // Deferred to next tick so it fires AFTER the current synchronous
-        // init sequence completes — avoids interleaving with alt-screen/mouse
-        // tracking enable writes that may happen in the same render cycle.
-        setImmediate(() => {
-          void Promise.all([this.querier.send(xtversion()), this.querier.flush()]).then(([r]) => {
-            if (r) {
-              setXtversionName(r.name);
-              defaultCallbacks.logForDebugging(`XTVERSION: terminal identified as "${r.name}"`);
-            } else {
-              defaultCallbacks.logForDebugging('XTVERSION: no reply (terminal ignored query)');
-            }
+        stdin.addListener('readable', this.handleReadable);
+        if (rawModeSupported) {
+          // Enable bracketed paste mode
+          this.props.stdout.write(EBP);
+          // Enable terminal focus reporting (DECSET 1004)
+          this.props.stdout.write(EFE);
+          // Enable extended key reporting so ctrl+shift+<letter> is
+          // distinguishable from ctrl+<letter>. We write both the kitty stack
+          // push (CSI >1u) and xterm modifyOtherKeys level 2 (CSI >4;2m) —
+          // terminals honor whichever they implement (tmux only accepts the
+          // latter).
+          if (supportsExtendedKeys()) {
+            this.props.stdout.write(ENABLE_KITTY_KEYBOARD);
+            this.props.stdout.write(ENABLE_MODIFY_OTHER_KEYS);
+          }
+          // Probe terminal identity. XTVERSION survives SSH (query/reply goes
+          // through the pty), unlike TERM_PROGRAM. Used for wheel-scroll base
+          // detection when env vars are absent. Fire-and-forget: the DA1
+          // sentinel bounds the round-trip, and if the terminal ignores the
+          // query, flush() still resolves and name stays undefined.
+          // Deferred to next tick so it fires AFTER the current synchronous
+          // init sequence completes — avoids interleaving with alt-screen/mouse
+          // tracking enable writes that may happen in the same render cycle.
+          setImmediate(() => {
+            void Promise.all([this.querier.send(xtversion()), this.querier.flush()]).then(([r]) => {
+              if (r) {
+                setXtversionName(r.name);
+                defaultCallbacks.logForDebugging(`XTVERSION: terminal identified as "${r.name}"`);
+              } else {
+                defaultCallbacks.logForDebugging('XTVERSION: no reply (terminal ignored query)');
+              }
+            });
           });
-        });
+        }
       }
 
       this.rawModeEnabledCount++;
@@ -366,13 +384,16 @@ export default class App extends PureComponent<Props, State> {
         return;
       }
 
-      this.props.stdout.write(DISABLE_MODIFY_OTHER_KEYS);
-      this.props.stdout.write(DISABLE_KITTY_KEYBOARD);
-      // Disable terminal focus reporting (DECSET 1004)
-      this.props.stdout.write(DFE);
-      // Disable bracketed paste mode
-      this.props.stdout.write(DBP);
-      stdin.setRawMode(false);
+      if (this.rawModeActive) {
+        this.props.stdout.write(DISABLE_MODIFY_OTHER_KEYS);
+        this.props.stdout.write(DISABLE_KITTY_KEYBOARD);
+        // Disable terminal focus reporting (DECSET 1004)
+        this.props.stdout.write(DFE);
+        // Disable bracketed paste mode
+        this.props.stdout.write(DBP);
+        stdin.setRawMode(false);
+        this.rawModeActive = false;
+      }
       stdin.removeListener('readable', this.handleReadable);
       stdin.unref();
     }
@@ -480,7 +501,7 @@ export default class App extends PureComponent<Props, State> {
   };
 
   handleExit = (error?: Error): void => {
-    if (this.isRawModeSupported()) {
+    if (this.rawModeEnabledCount > 0) {
       this.handleSetRawMode(false);
     }
 

packages/@ant/ink/src/core/__tests__/raw-mode-support.test.ts

@@ -0,0 +1,53 @@
+import { describe, expect, test } from 'bun:test';
+import {
+  isWindowsRawModeUnsafe,
+  supportsStdinRawMode,
+} from '../raw-mode-support.js';
+
+describe('isWindowsRawModeUnsafe', () => {
+  test('does not disable raw mode for ordinary Windows shells', () => {
+    expect(
+      isWindowsRawModeUnsafe({
+        ComSpec: 'C:\\Windows\\System32\\cmd.exe',
+      }, 'win32'),
+    ).toBe(false);
+    expect(
+      isWindowsRawModeUnsafe({
+        PSModulePath: 'C:\\Program Files\\PowerShell\\Modules',
+      }, 'win32'),
+    ).toBe(false);
+  });
+
+  test('disables raw mode for MSYS2 and Cygwin terminals', () => {
+    expect(isWindowsRawModeUnsafe({ MSYSTEM: 'UCRT64' }, 'win32')).toBe(true);
+    expect(isWindowsRawModeUnsafe({ TERM: 'cygwin' }, 'win32')).toBe(true);
+    expect(isWindowsRawModeUnsafe({ TERM_PROGRAM: 'mintty' }, 'win32')).toBe(
+      true,
+    );
+    expect(isWindowsRawModeUnsafe({ SHELL: '/usr/bin/bash' }, 'win32')).toBe(
+      false,
+    );
+    expect(
+      isWindowsRawModeUnsafe({ SHELL: '/usr/bin/msys2_shell.cmd' }, 'win32'),
+    ).toBe(true);
+  });
+
+  test('supports an explicit emergency disable switch', () => {
+    expect(
+      isWindowsRawModeUnsafe({
+        CLAUDE_CODE_DISABLE_STDIN_RAW_MODE: '1',
+      }, 'win32'),
+    ).toBe(true);
+  });
+});
+
+describe('supportsStdinRawMode', () => {
+  test('requires a TTY stream with setRawMode', () => {
+    expect(supportsStdinRawMode({ isTTY: false } as NodeJS.ReadStream)).toBe(
+      false,
+    );
+    expect(supportsStdinRawMode({ isTTY: true } as NodeJS.ReadStream)).toBe(
+      false,
+    );
+  });
+});

packages/@ant/ink/src/core/raw-mode-support.ts

@@ -0,0 +1,43 @@
+function isEnvTruthy(value: string | undefined): boolean {
+  return value === '1' || value === 'true';
+}
+
+export function isWindowsRawModeUnsafe(
+  env: NodeJS.ProcessEnv = process.env,
+  platform: NodeJS.Platform = process.platform,
+): boolean {
+  if (platform !== 'win32') {
+    return false;
+  }
+
+  if (isEnvTruthy(env.CLAUDE_CODE_DISABLE_STDIN_RAW_MODE)) {
+    return true;
+  }
+
+  const term = env.TERM?.toLowerCase() ?? '';
+  const termProgram = env.TERM_PROGRAM?.toLowerCase() ?? '';
+  const msystem = env.MSYSTEM?.toLowerCase() ?? '';
+  const shell = env.SHELL?.toLowerCase() ?? '';
+
+  return (
+    term === 'cygwin' ||
+    term.includes('mintty') ||
+    termProgram.includes('mintty') ||
+    msystem.length > 0 ||
+    shell.includes('msys') ||
+    shell.includes('cygwin') ||
+    shell.includes('mingw')
+  );
+}
+
+export function supportsStdinRawMode(stdin: NodeJS.ReadStream): boolean {
+  if (!stdin.isTTY) {
+    return false;
+  }
+
+  if (isWindowsRawModeUnsafe(process.env, process.platform)) {
+    return false;
+  }
+
+  return typeof stdin.setRawMode === 'function';
+}

scripts/postinstall.cjs

@@ -13,7 +13,7 @@
 
 const { existsSync, mkdirSync, readFileSync, renameSync, rmSync, statSync, writeFileSync, chmodSync } =
   require("fs")
-const { spawnSync } = require("child_process")
+const { spawn, spawnSync } = require("child_process")
 const { setDefaultResultOrder } = require("node:dns")
 const path = require("path")
 const os = require("os")
@@ -97,6 +97,110 @@ function getBinaryPath() {
   return path.resolve(dir, subdir, binary)
 }
 
+function safeResolve(...parts) {
+  const filtered = parts.filter(Boolean)
+  if (filtered.length === 0) return null
+  return path.resolve(...filtered)
+}
+
+function removePowerShellShimIfOwned(shimPath) {
+  if (!shimPath || !existsSync(shimPath)) return false
+  const cmdShimPath = shimPath.replace(/\.ps1$/i, ".cmd")
+  if (!existsSync(cmdShimPath)) return false
+
+  let content
+  try {
+    content = readFileSync(shimPath, "utf8")
+  } catch {
+    return false
+  }
+
+  // Only remove npm-generated shims for this package. PowerShell resolves
+  // csc.ps1 before csc.cmd, and enterprise ExecutionPolicy often blocks .ps1
+  // launchers while cmd.exe works. Removing this shim makes PowerShell fall
+  // through to the same .cmd launcher used by cmd.exe.
+  const normalized = content.replace(/\\/g, "/")
+  if (!normalized.includes("@costrict") && !normalized.includes("dist/cli-node.js")) {
+    return false
+  }
+
+  try {
+    rmSync(shimPath, { force: true })
+    console.log(`[postinstall] Removed PowerShell shim ${shimPath}; PowerShell will use csc.cmd`)
+    return true
+  } catch (error) {
+    console.warn(
+      `[postinstall] Could not remove PowerShell shim ${shimPath}: ${
+        error instanceof Error ? error.message : String(error)
+      }`,
+    )
+    return false
+  }
+}
+
+function cleanupWindowsPowerShellShim() {
+  if (process.platform !== "win32") return
+
+  const dirs = getWindowsPowerShellShimDirs()
+  const seen = new Set()
+  for (const dir of dirs) {
+    const shimPath = path.join(dir, "csc.ps1")
+    if (seen.has(shimPath)) continue
+    seen.add(shimPath)
+    removePowerShellShimIfOwned(shimPath)
+  }
+}
+
+function getWindowsPowerShellShimDirs() {
+  return [
+    safeResolve(process.env.npm_config_prefix),
+    safeResolve(process.env.npm_config_local_prefix, "node_modules", ".bin"),
+    safeResolve(process.env.INIT_CWD, "node_modules", ".bin"),
+    safeResolve(projectRoot, "node_modules", ".bin"),
+  ].filter(Boolean)
+}
+
+function scheduleWindowsPowerShellShimCleanup() {
+  if (process.platform !== "win32") return
+
+  const dirs = getWindowsPowerShellShimDirs()
+  if (dirs.length === 0) return
+
+  const script = String.raw`
+const { existsSync, readFileSync, rmSync } = require("fs");
+const path = require("path");
+const dirs = JSON.parse(process.argv[1] || "[]");
+setTimeout(() => {
+  for (const dir of dirs) {
+    const shimPath = path.join(dir, "csc.ps1");
+    const cmdShimPath = path.join(dir, "csc.cmd");
+    if (!existsSync(shimPath) || !existsSync(cmdShimPath)) continue;
+    let content = "";
+    try {
+      content = readFileSync(shimPath, "utf8").replace(/\\/g, "/");
+    } catch {
+      continue;
+    }
+    if (!content.includes("@costrict") && !content.includes("dist/cli-node.js")) continue;
+    try {
+      rmSync(shimPath, { force: true });
+    } catch {}
+  }
+}, 3000);
+`
+
+  try {
+    const child = spawn(process.execPath, ["-e", script, JSON.stringify(dirs)], {
+      detached: true,
+      stdio: "ignore",
+      windowsHide: true,
+    })
+    child.unref()
+  } catch {
+    // Best effort only. Immediate cleanup above covers the normal npm flow.
+  }
+}
+
 // --- Download helpers ---
 
 function proxyEnvSet() {
@@ -341,6 +445,8 @@ async function downloadAndExtract() {
 }
 
 async function main() {
+  cleanupWindowsPowerShellShim()
+  scheduleWindowsPowerShellShimCleanup()
   await downloadAndExtract()
 }
 

src/main.tsx

@@ -233,6 +233,7 @@ import { getGhAuthStatus } from "./utils/github/ghAuthStatus.js";
 import { safeParseJSON } from "./utils/json.js";
 import { logError } from "./utils/log.js";
 import { getModelDeprecationWarning } from "./utils/model/deprecation.js";
+import { shouldUseNonInteractiveSession } from "./utils/nonInteractiveSession.js";
 import {
 	getDefaultMainLoopModel,
 	getUserSpecifiedModelSetting,
@@ -1134,15 +1135,16 @@ export async function main() {
 		}
 	}
 
-		// Check for -p/--print and --init-only flags early to set isInteractiveSession before init()
-		// This is needed because telemetry initialization calls auth functions that need this flag
-		const cliArgs = process.argv.slice(2);
-		const hasPrintFlag = cliArgs.includes("-p") || cliArgs.includes("--print");
-		const hasInitOnlyFlag = cliArgs.includes("--init-only");
-		const hasSdkUrl = cliArgs.some((arg) => arg.startsWith("--sdk-url"));
-		const forceInteractive = isEnvTruthy(process.env.CLAUDE_CODE_FORCE_INTERACTIVE);
-		const isNonInteractive =
-			hasPrintFlag || hasInitOnlyFlag || hasSdkUrl || (!forceInteractive && !process.stdout.isTTY);
+	// Check for -p/--print and --init-only flags early to set isInteractiveSession before init()
+	// This is needed because telemetry initialization calls auth functions that need this flag
+	const cliArgs = process.argv.slice(2);
+	const forceInteractive = isEnvTruthy(process.env.CLAUDE_CODE_FORCE_INTERACTIVE);
+	const isNonInteractive = shouldUseNonInteractiveSession({
+		args: cliArgs,
+		forceInteractive,
+		stdinIsTTY: process.stdin.isTTY,
+		stdoutIsTTY: process.stdout.isTTY,
+	});
 
 	// Stop capturing early input for non-interactive modes
 	if (isNonInteractive) {

src/utils/__tests__/nonInteractiveSession.test.ts

@@ -0,0 +1,80 @@
+import { describe, expect, test } from 'bun:test'
+import { shouldUseNonInteractiveSession } from '../nonInteractiveSession.js'
+
+describe('shouldUseNonInteractiveSession', () => {
+  test('uses non-interactive mode for explicit headless flags', () => {
+    expect(
+      shouldUseNonInteractiveSession({
+        args: ['--print'],
+        forceInteractive: false,
+        stdinIsTTY: true,
+        stdoutIsTTY: true,
+      }),
+    ).toBe(true)
+    expect(
+      shouldUseNonInteractiveSession({
+        args: ['-p'],
+        forceInteractive: true,
+        stdinIsTTY: true,
+        stdoutIsTTY: true,
+      }),
+    ).toBe(true)
+    expect(
+      shouldUseNonInteractiveSession({
+        args: ['--init-only'],
+        forceInteractive: false,
+        stdinIsTTY: true,
+        stdoutIsTTY: true,
+      }),
+    ).toBe(true)
+    expect(
+      shouldUseNonInteractiveSession({
+        args: ['--sdk-url=http://localhost:1234'],
+        forceInteractive: false,
+        stdinIsTTY: true,
+        stdoutIsTTY: true,
+      }),
+    ).toBe(true)
+  })
+
+  test('does not enter print mode for PowerShell shims that preserve stdin TTY', () => {
+    expect(
+      shouldUseNonInteractiveSession({
+        args: [],
+        forceInteractive: false,
+        stdinIsTTY: true,
+        stdoutIsTTY: false,
+      }),
+    ).toBe(false)
+  })
+
+  test('keeps automatic non-interactive mode when both stdio sides are non-TTY', () => {
+    expect(
+      shouldUseNonInteractiveSession({
+        args: [],
+        forceInteractive: false,
+        stdinIsTTY: false,
+        stdoutIsTTY: false,
+      }),
+    ).toBe(true)
+    expect(
+      shouldUseNonInteractiveSession({
+        args: [],
+        forceInteractive: false,
+        stdinIsTTY: undefined,
+        stdoutIsTTY: undefined,
+      }),
+    ).toBe(true)
+  })
+
+  test('forceInteractive only suppresses automatic non-interactive detection', () => {
+    expect(
+      shouldUseNonInteractiveSession({
+        args: [],
+        forceInteractive: true,
+        stdinIsTTY: false,
+        stdoutIsTTY: false,
+      }),
+    ).toBe(false)
+  })
+})

src/utils/earlyInput.ts

@@ -13,6 +13,39 @@
 
 import { lastGrapheme } from './intl.js'
 
+function isEnvTruthy(value: string | undefined): boolean {
+  return value === '1' || value === 'true'
+}
+
+function supportsEarlyInputRawMode(): boolean {
+  if (!process.stdin.isTTY || typeof process.stdin.setRawMode !== 'function') {
+    return false
+  }
+
+  if (process.platform !== 'win32') {
+    return true
+  }
+
+  if (isEnvTruthy(process.env.CLAUDE_CODE_DISABLE_STDIN_RAW_MODE)) {
+    return false
+  }
+
+  const term = process.env.TERM?.toLowerCase() ?? ''
+  const termProgram = process.env.TERM_PROGRAM?.toLowerCase() ?? ''
+  const msystem = process.env.MSYSTEM?.toLowerCase() ?? ''
+  const shell = process.env.SHELL?.toLowerCase() ?? ''
+
+  return !(
+    term === 'cygwin' ||
+    term.includes('mintty') ||
+    termProgram.includes('mintty') ||
+    msystem.length > 0 ||
+    shell.includes('msys') ||
+    shell.includes('cygwin') ||
+    shell.includes('mingw')
+  )
+}
+
 // Buffer for early input characters
 let earlyInputBuffer = ''
 // Flag to track if we're currently capturing
@@ -33,7 +66,7 @@ export function startCapturingEarlyInput(): void {
   // be in print mode. Raw mode disables ISIG (terminal Ctrl+C → SIGINT),
   // which would make -p uninterruptible.
   if (
-    !process.stdin.isTTY ||
+    !supportsEarlyInputRawMode() ||
     isCapturing ||
     process.argv.includes('-p') ||
     process.argv.includes('--print')

src/utils/nonInteractiveSession.ts

@@ -0,0 +1,27 @@
+export type NonInteractiveSessionOptions = {
+  args: string[]
+  forceInteractive: boolean
+  stdinIsTTY: boolean | undefined
+  stdoutIsTTY: boolean | undefined
+}
+
+export function shouldUseNonInteractiveSession({
+  args,
+  forceInteractive,
+  stdinIsTTY,
+  stdoutIsTTY,
+}: NonInteractiveSessionOptions): boolean {
+  if (args.includes('-p') || args.includes('--print')) return true
+  if (args.includes('--init-only')) return true
+  if (args.some(arg => arg.startsWith('--sdk-url'))) return true
+
+  if (forceInteractive) return false
+
+  const hasInteractiveStdin = stdinIsTTY === true
+  const hasInteractiveStdout = stdoutIsTTY === true
+
+  // Some Windows launchers, notably npm's generated PowerShell .ps1 shim,
+  // can hide stdout TTY status while stdin is still an interactive terminal.
+  // Treat that as interactive so a bare `csc` does not fall into --print mode.
+  return !hasInteractiveStdout && !hasInteractiveStdin
+}