Merge pull request #455

fix(input): make sure a prompt sent through the API actually leaves the composer

src/session-submit-verifier.ts

@@ -0,0 +1,133 @@
+/**
+ * @fileoverview Verify that a programmatically sent prompt actually LEFT the composer,
+ * and press Enter again while it has not.
+ *
+ * Claude Code 2.1.277 (auto-installed 2026-09-18) takes typed text the moment its
+ * composer paints but ignores Enter for the first 30 to 50 seconds after it, so the
+ * `send-keys -l <text>` + `send-keys Enter` pair `TmuxManager.sendInput()` sends 50 ms
+ * apart leaves the prompt sitting on the composer with `0 tokens`, and every caller
+ * that then waits for the turn (send-and-wait, the agent skill, the maintainer bot,
+ * cron, Ralph) burns its whole timeout on a turn that never started. Measured through
+ * the input route on 2026-09-19: an Enter at 28 s stranded, one at 51 s submitted.
+ *
+ * The rule: after a write that carried a carriage return, read the pane on a short
+ * schedule; while the LAST composer line (the CLI's own prompt glyph) still holds the
+ * head of what was sent, send Enter again. An empty composer ends it, and so does a
+ * composer holding anything else, because that text is the user's or the CLI's, never
+ * ours. A pane with no composer line at all (a shell, a CLI whose glyph is not
+ * declared, a direct-PTY session with no pane to read) does nothing: this runs for
+ * EVERY programmatic sender, so a blind Enter here could confirm a dialog nobody asked
+ * about. The composer is the last glyph line on purpose: Claude Code echoes a submitted
+ * prompt with the same glyph higher up in the transcript, so only the last one says
+ * whether the text was taken.
+ *
+ * Pure apart from the injected capture, send and log, so the schedule, the cap and
+ * every stop condition are unit-tested with fake timers (test/session-submit-verifier.test.ts).
+ */
+import { stripAnsi } from './utils/index.js';
+
+/**
+ * When to look, counted from the write: 2 s catches the common case (taken) with one
+ * capture, and the tail reaches 60 s, past twice the longest window measured. Enter is
+ * re-sent at every check that still finds the prompt, so a 50 s window costs about
+ * seven Enters and one capture each; a taken prompt costs one capture.
+ */
+export const SUBMIT_VERIFY_DELAYS_MS: readonly number[] = [
+  2_000, 3_000, 5_000, 5_000, 5_000, 10_000, 10_000, 10_000, 10_000,
+];
+
+/** How many leading characters of the prompt have to match, whitespace removed. */
+const PROMPT_HEAD_CHARS = 24;
+
+const compact = (s: string): string => s.replace(/\s+/g, '');
+
+/**
+ * Whether `prompt` is still sitting unsubmitted in the composer of `screen`.
+ *
+ * - `true`: the last `glyph` line holds the prompt's head.
+ * - `false`: the composer is empty (the prompt was taken) or holds other text.
+ * - `undefined`: no composer line at all; nothing can be said, so nothing is sent.
+ *
+ * Whitespace is removed on both sides before comparing, because the composer wraps a
+ * long prompt onto indented continuation lines and Claude Code draws a no-break space
+ * after the glyph; `\s` covers that one in JavaScript.
+ */
+export function promptStillInComposer(screen: string, prompt: string, glyph: string): boolean | undefined {
+  if (!glyph) return undefined;
+  const composerLines = stripAnsi(screen)
+    .split('\n')
+    .map((l) => l.trim())
+    .filter((l) => l.startsWith(glyph));
+  if (composerLines.length === 0) return undefined;
+  const composer = compact(composerLines[composerLines.length - 1].slice(glyph.length));
+  if (!composer) return false;
+  const head = compact(prompt).slice(0, PROMPT_HEAD_CHARS);
+  return head.length > 0 && composer.startsWith(head);
+}
+
+export interface SubmitVerifierDeps {
+  /** The rendered pane, or null when there is none to read. */
+  capture: () => string | null | undefined;
+  /** Press Enter once. Failures are swallowed; the next check decides again. */
+  sendEnter: () => Promise<unknown> | unknown;
+  /** The CLI's composer glyph, resolved at check time (the registry can change). */
+  glyph: () => string;
+  log?: (message: string) => void;
+  /** Test seam; production uses SUBMIT_VERIFY_DELAYS_MS. */
+  delaysMs?: readonly number[];
+}
+
+/**
+ * One per session. `arm(text)` starts the schedule for the prompt just sent and
+ * cancels any earlier one: a newer write owns the composer now, and re-sending Enter
+ * for an older prompt could submit the newer one early. `cancel()` is for teardown.
+ */
+export class SubmitVerifier {
+  private timer: NodeJS.Timeout | null = null;
+  private generation = 0;
+
+  constructor(private readonly deps: SubmitVerifierDeps) {}
+
+  arm(text: string): void {
+    this.cancel();
+    const gen = this.generation;
+    const delays = this.deps.delaysMs ?? SUBMIT_VERIFY_DELAYS_MS;
+    let step = 0;
+    let elapsed = 0;
+    let resent = 0;
+
+    const schedule = (): void => {
+      if (step >= delays.length) return;
+      const delay = delays[step++];
+      elapsed += delay;
+      this.timer = setTimeout(() => void check(), delay);
+      this.timer.unref?.();
+    };
+    const check = async (): Promise<void> => {
+      this.timer = null;
+      if (gen !== this.generation) return;
+      const screen = this.deps.capture();
+      if (promptStillInComposer(screen ?? '', text, this.deps.glyph()) !== true) return;
+      resent++;
+      this.deps.log?.(
+        `prompt still in the composer after ${Math.round(elapsed / 1000)}s, re-sending Enter (${resent}/${delays.length})`
+      );
+      try {
+        await this.deps.sendEnter();
+      } catch {
+        // The next check re-reads the screen and decides again.
+      }
+      if (gen !== this.generation) return;
+      schedule();
+    };
+    schedule();
+  }
+
+  cancel(): void {
+    this.generation++;
+    if (this.timer) {
+      clearTimeout(this.timer);
+      this.timer = null;
+    }
+  }
+}

src/session.ts

@@ -110,6 +110,7 @@ import {
 import { DEFAULT_TMUX_HISTORY_LIMIT } from './config/terminal-history.js';
 import { EXEC_TIMEOUT_MS } from './config/exec-timeout.js';
 import { getCli } from './config/cli-registry/registry.js';
+import { SubmitVerifier } from './session-submit-verifier.js';
 import { compileVersionRegex } from './config/cli-registry/patterns.js';
 import { resolveSessionCliVersion } from './utils/cli-resolver.js';
 import {
@@ -502,6 +503,8 @@ export class Session extends EventEmitter {
   private _trustDialogAttempts = 0; // Keystrokes sent at the trust dialog
   private _lastTrustDialogScanAt = 0; // Throttle for the trust-dialog screen read
   private _trustDialogTimer: NodeJS.Timeout | null = null; // Re-read after a keystroke (see below)
+  /** Re-sends Enter while a programmatic prompt still sits in the composer (session-submit-verifier.ts). */
+  private _submitVerifier: SubmitVerifier | null = null;
   private _interactiveStartedAt = 0; // When the interactive pane launched (bounds that scan)
   private _taskTracker: TaskTracker;
 
@@ -3190,6 +3193,9 @@ export class Session extends EventEmitter {
   }
 
   private _clearAllTimers(): void {
+    // Stop re-sending Enter for a prompt this session will never take now
+    this._submitVerifier?.cancel();
+    this._submitVerifier = null;
     // Clear the workspace-trust follow-up read
     if (this._trustDialogTimer) {
       clearTimeout(this._trustDialogTimer);
@@ -3721,7 +3727,10 @@ export class Session extends EventEmitter {
     const submittedPrompt = this._trackSubmit(data, options);
     if (this._mux && this._muxSession) {
       const sent = await this._mux.sendInput(this.id, data);
-      if (sent) this._emitSubmittedPrompt(submittedPrompt);
+      if (sent) {
+        this._emitSubmittedPrompt(submittedPrompt);
+        this._verifySubmitted(data);
+      }
       return sent;
     }
     // Fallback to PTY write
@@ -3733,6 +3742,28 @@ export class Session extends EventEmitter {
     return false;
   }
 
+  /**
+   * Arm the composer check for a write that carried Enter (session-submit-verifier.ts):
+   * Claude Code 2.1.277+ ignores Enter for the first 30-50 s after the composer paints,
+   * so the pair `sendInput` just sent can leave the text stranded. Only a mux session
+   * can read its pane, only text can be stranded, and the glyph is the CLI's own.
+   */
+  private _verifySubmitted(data: string): void {
+    if (!data.includes('\r') || !this._mux?.capturePaneText || !this._muxSession) return;
+    const text = data.replace(/[\r\n]/g, '').trimEnd();
+    if (!text) return;
+    this._submitVerifier ??= new SubmitVerifier({
+      capture: () =>
+        this._isStopped || !this._mux || !this._muxSession
+          ? null
+          : this._mux.capturePaneText?.(this._muxSession.muxName),
+      sendEnter: () => this._mux?.sendInput(this.id, '\r'),
+      glyph: () => getCli(this.mode)?.capabilities.workDetect?.promptGlyph ?? '❯',
+      log: (m) => console.log(`[Session ${this.id.slice(0, 8)}] ${m}`),
+    });
+    this._submitVerifier.arm(text);
+  }
+
   /** Current PTY dimensions — used to skip no-op resizes that trigger Ink redraws */
   private _ptyCols = 120;
   private _ptyRows = 40;