feat: fork ink and make it work nicely

ui-tui/packages/hermes-ink/src/ink/clearTerminal.ts

@@ -0,0 +1,68 @@
+/**
+ * Cross-platform terminal clearing with scrollback support.
+ * Detects modern terminals that support ESC[3J for clearing scrollback.
+ */
+
+import { csi, CURSOR_HOME, ERASE_SCREEN, ERASE_SCROLLBACK } from './termio/csi.js'
+
+// HVP (Horizontal Vertical Position) - legacy Windows cursor home
+const CURSOR_HOME_WINDOWS = csi(0, 'f')
+
+function isWindowsTerminal(): boolean {
+  return process.platform === 'win32' && !!process.env.WT_SESSION
+}
+
+function isMintty(): boolean {
+  // mintty 3.1.5+ sets TERM_PROGRAM to 'mintty'
+  if (process.env.TERM_PROGRAM === 'mintty') {
+    return true
+  }
+
+  // GitBash/MSYS2/MINGW use mintty and set MSYSTEM
+  if (process.platform === 'win32' && process.env.MSYSTEM) {
+    return true
+  }
+
+  return false
+}
+
+function isModernWindowsTerminal(): boolean {
+  // Windows Terminal sets WT_SESSION environment variable
+  if (isWindowsTerminal()) {
+    return true
+  }
+
+  // VS Code integrated terminal on Windows with ConPTY support
+  if (process.platform === 'win32' && process.env.TERM_PROGRAM === 'vscode' && process.env.TERM_PROGRAM_VERSION) {
+    return true
+  }
+
+  // mintty (GitBash/MSYS2/Cygwin) supports modern escape sequences
+  if (isMintty()) {
+    return true
+  }
+
+  return false
+}
+
+/**
+ * Returns the ANSI escape sequence to clear the terminal including scrollback.
+ * Automatically detects terminal capabilities.
+ */
+export function getClearTerminalSequence(): string {
+  if (process.platform === 'win32') {
+    if (isModernWindowsTerminal()) {
+      return ERASE_SCREEN + ERASE_SCROLLBACK + CURSOR_HOME
+    } else {
+      // Legacy Windows console - can't clear scrollback
+      return ERASE_SCREEN + CURSOR_HOME_WINDOWS
+    }
+  }
+
+  return ERASE_SCREEN + ERASE_SCROLLBACK + CURSOR_HOME
+}
+
+/**
+ * Clears the terminal screen. On supported terminals, also clears scrollback.
+ */
+export const clearTerminal = getClearTerminalSequence()