fix(repl): queue prompt guidance for next turn (#333)

Keep normal prompt submissions during generation queued instead of interrupting the current turn. Add a visible next-turn banner in the prompt area so users can tell their follow-up guidance was accepted, and cover the new behavior with focused tests.

Fixes #328

Co-authored-by: Claude <noreply@anthropic.com>

src/utils/handlePromptSubmit.test.ts

@@ -0,0 +1,89 @@
+import { afterEach, beforeEach, describe, expect, it, mock } from 'bun:test'
+import { getCommandQueue, resetCommandQueue } from './messageQueueManager.js'
+
+describe('handlePromptSubmit', () => {
+  beforeEach(() => {
+    resetCommandQueue()
+    mock.module('src/services/analytics/index.js', () => ({
+      logEvent: () => {},
+    }))
+  })
+
+  afterEach(() => {
+    resetCommandQueue()
+    mock.restore()
+  })
+
+  it('queues prompt submissions during generation without interrupting the current turn', async () => {
+    const { handlePromptSubmit } = await import('./handlePromptSubmit.js')
+
+    const abortCalls: unknown[] = []
+    const inputChanges: string[] = []
+    let cursorOffset = 123
+    let bufferCleared = false
+    let pastedContentsCleared = false
+    let historyReset = false
+
+    await handlePromptSubmit({
+      input: '  use another library  ',
+      mode: 'prompt',
+      pastedContents: {},
+      helpers: {
+        setCursorOffset: offset => {
+          cursorOffset = offset
+        },
+        clearBuffer: () => {
+          bufferCleared = true
+        },
+        resetHistory: () => {
+          historyReset = true
+        },
+      },
+      onInputChange: value => {
+        inputChanges.push(value)
+      },
+      setPastedContents: updater => {
+        const nextValue =
+          typeof updater === 'function'
+            ? updater({ 1: { id: 1, type: 'text', content: 'x' } })
+            : updater
+        pastedContentsCleared = Object.keys(nextValue).length === 0
+      },
+      abortController: {
+        abort: (reason: unknown) => {
+          abortCalls.push(reason)
+        },
+      } as never,
+      hasInterruptibleToolInProgress: true,
+      queryGuard: {
+        isActive: true,
+      } as never,
+      isExternalLoading: false,
+      commands: [],
+      messages: [],
+      mainLoopModel: 'sonnet',
+      ideSelection: undefined,
+      querySource: 'repl' as never,
+      setToolJSX: () => {},
+      getToolUseContext: () => ({}) as never,
+      setUserInputOnProcessing: () => {},
+      setAbortController: () => {},
+      onQuery: async () => {},
+      setAppState: () => ({}) as never,
+    })
+
+    expect(abortCalls).toEqual([])
+    expect(inputChanges).toEqual([''])
+    expect(cursorOffset).toBe(0)
+    expect(bufferCleared).toBe(true)
+    expect(pastedContentsCleared).toBe(true)
+    expect(historyReset).toBe(true)
+    expect(getCommandQueue()).toMatchObject([
+      {
+        value: 'use another library',
+        preExpansionValue: 'use another library',
+        mode: 'prompt',
+      },
+    ])
+  })
+})

src/utils/handlePromptSubmit.ts

@@ -316,9 +316,10 @@ export async function handlePromptSubmit(
       return
     }
 
-    // Interrupt the current turn when all executing tools have
-    // interruptBehavior 'cancel' (e.g. SleepTool).
-    if (params.hasInterruptibleToolInProgress) {
+    // Prompt submissions during generation should guide the next turn without
+    // interrupting the current one. Keep the explicit interrupt path only for
+    // non-prompt inputs that opt into that behavior.
+    if (mode !== 'prompt' && params.hasInterruptibleToolInProgress) {
       logForDebugging(
         `[interrupt] Aborting current turn: streamMode=${params.streamMode}`,
       )