fix(runtime): close async cleanup and framing races

packages/pty/pty-local/src/index.ts

@@ -14,6 +14,7 @@ import type { SandboxMode } from '@deepseek-ai/dsh-sandbox'
 import { effectiveSandboxMode } from '@deepseek-ai/dsh-sandbox-policy'
 import { type Config, type ResolvedConfig, validateConfig } from './config.ts'
 import { LocalPtySession } from './session.ts'
+import { CONTROLLED_PROMPT } from './sanitize.ts'
 
 export { Config } from './config.ts'
 export type { Config as PtyLocalConfig } from './config.ts'
@@ -58,7 +59,7 @@ function childEnvironment(spec: PtyBackendSpawnSpec): Record<string, string> {
     TERM: 'dumb',
     PAGER: 'cat',
     GIT_PAGER: 'cat',
-    PS1: 'dsh> ',
+    PS1: CONTROLLED_PROMPT,
     PROMPT_COMMAND: 'printf "\\033]133;D;%s\\007" "$?"',
     BASH_SILENCE_DEPRECATION_WARNING: '1',
     DSH_SHELL: '1',

packages/pty/pty-local/src/sanitize.ts

@@ -5,12 +5,15 @@ import { Buffer } from 'node:buffer'
 /** OSC marker emitted by the controlled bash before each prompt. */
 export const PROMPT_MARKER_PREFIX = '133;D;'
 
+/** Exact printable prompt emitted after the private marker. */
+export const CONTROLLED_PROMPT = 'dsh> '
+
 /** One sanitized chunk plus whether it contained the owned prompt marker. */
 export interface SanitizedChunk {
   text: string
   prompt: boolean
-  /** Present when printable text followed the latest owned prompt marker. */
-  promptText?: true
+  /** Printable text after the latest owned marker in this chunk. */
+  promptTail?: string
 }
 
 /**
@@ -23,7 +26,7 @@ export class TerminalSanitizer {
   private discardMode: 'osc' | 'csi' | undefined
   private discardOscEscape = false
   private trailingCarriageReturn = false
-  private awaitingPromptText = false
+  private trackingPromptTail = false
 
   constructor(private readonly maxPendingBytes: number) {}
 
@@ -36,24 +39,21 @@ export class TerminalSanitizer {
     this.pending += this.discardPrefix(chunk)
     let text = ''
     let prompt = false
-    let promptText = false
+    let includePromptTail = this.trackingPromptTail
+    let promptTail = ''
     let index = 0
-    const appendText = (value: string): boolean => {
+    const appendText = (value: string): void => {
       text += value
-      if (this.awaitingPromptText && value.replace(/[\r\n\x07]/g, '').length > 0) {
-        this.awaitingPromptText = false
-        return true
-      }
-      return false
+      if (this.trackingPromptTail) promptTail += value
     }
     while (index < this.pending.length) {
       const escape = this.pending.indexOf('\x1b', index)
       if (escape < 0) {
-        promptText = appendText(this.pending.slice(index)) || promptText
+        appendText(this.pending.slice(index))
         index = this.pending.length
         break
       }
-      promptText = appendText(this.pending.slice(index, escape)) || promptText
+      appendText(this.pending.slice(index, escape))
       if (escape + 1 >= this.pending.length) {
         index = escape
         break
@@ -74,8 +74,9 @@ export class TerminalSanitizer {
         const content = this.pending.slice(escape + 2, end - terminatorBytes)
         if (content.startsWith(PROMPT_MARKER_PREFIX)) {
           prompt = true
-          promptText = false
-          this.awaitingPromptText = true
+          this.trackingPromptTail = true
+          includePromptTail = true
+          promptTail = ''
         }
         index = end
         continue
@@ -99,7 +100,11 @@ export class TerminalSanitizer {
     }
     this.pending = this.pending.slice(index)
     this.enforcePendingBound()
-    return { text: this.normalizeText(text), prompt, ...promptText ? { promptText: true } : {} }
+    return {
+      text: this.normalizeText(text),
+      prompt,
+      ...includePromptTail ? { promptTail } : {},
+    }
   }
 
   /**
@@ -111,7 +116,7 @@ export class TerminalSanitizer {
     this.pending = ''
     this.discardMode = undefined
     this.discardOscEscape = false
-    this.awaitingPromptText = false
+    this.trackingPromptTail = false
     const normalized = this.normalizeText(text)
     if (!this.trailingCarriageReturn) return normalized
     this.trailingCarriageReturn = false

packages/pty/pty-local/src/session.ts

@@ -20,7 +20,7 @@ import type {
   PtyWaitReason,
 } from '@deepseek-ai/dsh-pty'
 import type { ResolvedConfig } from './config.ts'
-import { TerminalSanitizer } from './sanitize.ts'
+import { CONTROLLED_PROMPT, TerminalSanitizer } from './sanitize.ts'
 
 function utf8Tail(text: string, maxBytes: number): { text: string; truncated: boolean } {
   if (Buffer.byteLength(text) <= maxBytes) return { text, truncated: false }
@@ -77,6 +77,7 @@ class LocalSendOperation implements PtySendOperation {
   private readonly output: BoundedTextBuffer
   private readonly promise: PromiseWithResolvers<PtySendResult>
   private finished = false
+  private cancellationRequested = false
   private initialForegroundLeftWait: boolean
   private initialForegroundPgid: number | undefined
 
@@ -98,6 +99,10 @@ class LocalSendOperation implements PtySendOperation {
     return this.finished
   }
 
+  get cancelRequested(): boolean {
+    return this.cancellationRequested
+  }
+
   append(text: string): void {
     if (!this.finished) this.output.append(text)
   }
@@ -140,6 +145,7 @@ class LocalSendOperation implements PtySendOperation {
 
   cancel(): boolean {
     if (this.finished) return false
+    this.cancellationRequested = true
     this.onCancel()
     return true
   }
@@ -164,6 +170,7 @@ export class LocalPtySession implements PtyBackendSession {
   private polling = false
   private promptSeen = false
   private promptTextSeen = false
+  private promptTail = ''
   private shellPgid: number | undefined
   private initializing = false
   private lastOutputAt = Date.now()
@@ -223,6 +230,7 @@ export class LocalPtySession implements PtyBackendSession {
     this.lastOutputAt = Date.now()
     this.promptSeen = false
     this.promptTextSeen = false
+    this.promptTail = ''
 
     if (request.signal !== undefined) {
       const onAbort = (): void => { operation.cancel() }
@@ -242,7 +250,7 @@ export class LocalPtySession implements PtyBackendSession {
       if (this.active !== operation || this.closing) return
       operation.setInitialForeground(foreground)
       const input = `${request.text}${request.submit ? '\r' : ''}`
-      if (input.length > 0) {
+      if (input.length > 0 && !operation.cancelRequested) {
         this.writing = operation
         try {
           await this.terminal.write(Buffer.from(input, 'utf8'))
@@ -347,10 +355,14 @@ export class LocalPtySession implements PtyBackendSession {
       // to the foreground process group. Retain the marker; polling below is
       // the authority that accepts it only after bash owns the foreground.
       this.promptSeen = true
-      this.promptTextSeen = sanitized.promptText === true
+      this.promptTail = ''
       this.lastOutputAt = Date.now()
-    } else if (this.promptSeen && sanitized.promptText === true) {
-      this.promptTextSeen = true
+    }
+    if (this.promptSeen && sanitized.promptTail !== undefined) {
+      const remaining = Math.max(0, CONTROLLED_PROMPT.length + 1 - this.promptTail.length)
+      this.promptTail += sanitized.promptTail.slice(0, remaining)
+      if (sanitized.promptTail.length > remaining) this.promptTail = `${CONTROLLED_PROMPT}\0`
+      this.promptTextSeen = this.promptTail === CONTROLLED_PROMPT
     }
   }