fix(ralph-loop): scope completion detection to messages since loop start

src/hooks/ralph-loop/completion-promise-detector.test.ts

@@ -0,0 +1,105 @@
+/// <reference types="bun-types" />
+import { describe, expect, test } from "bun:test"
+import type { PluginInput } from "@opencode-ai/plugin"
+import { detectCompletionInSessionMessages } from "./completion-promise-detector"
+
+type SessionMessage = {
+  info?: { role?: string }
+  parts?: Array<{ type: string; text?: string }>
+}
+
+function createPluginInput(messages: SessionMessage[]): PluginInput {
+  return {
+    client: {
+      session: {
+        messages: async () => ({ data: messages }),
+      },
+    },
+  } as PluginInput
+}
+
+describe("detectCompletionInSessionMessages", () => {
+  describe("#given session with prior DONE and new messages", () => {
+    test("#when sinceMessageIndex excludes prior DONE #then should NOT detect completion", async () => {
+      // #given
+      const messages: SessionMessage[] = [
+        {
+          info: { role: "assistant" },
+          parts: [{ type: "text", text: "Old completion <promise>DONE</promise>" }],
+        },
+        {
+          info: { role: "assistant" },
+          parts: [{ type: "text", text: "Working on the new task" }],
+        },
+      ]
+      const ctx = createPluginInput(messages)
+
+      // #when
+      const detected = await detectCompletionInSessionMessages(ctx, {
+        sessionID: "session-123",
+        promise: "DONE",
+        apiTimeoutMs: 1000,
+        directory: "/tmp",
+        sinceMessageIndex: 1,
+      })
+
+      // #then
+      expect(detected).toBe(false)
+    })
+
+    test("#when sinceMessageIndex includes current DONE #then should detect completion", async () => {
+      // #given
+      const messages: SessionMessage[] = [
+        {
+          info: { role: "assistant" },
+          parts: [{ type: "text", text: "Old completion <promise>DONE</promise>" }],
+        },
+        {
+          info: { role: "assistant" },
+          parts: [{ type: "text", text: "Current completion <promise>DONE</promise>" }],
+        },
+      ]
+      const ctx = createPluginInput(messages)
+
+      // #when
+      const detected = await detectCompletionInSessionMessages(ctx, {
+        sessionID: "session-123",
+        promise: "DONE",
+        apiTimeoutMs: 1000,
+        directory: "/tmp",
+        sinceMessageIndex: 1,
+      })
+
+      // #then
+      expect(detected).toBe(true)
+    })
+  })
+
+  describe("#given no sinceMessageIndex (backward compat)", () => {
+    test("#then should scan all messages", async () => {
+      // #given
+      const messages: SessionMessage[] = [
+        {
+          info: { role: "assistant" },
+          parts: [{ type: "text", text: "Old completion <promise>DONE</promise>" }],
+        },
+        {
+          info: { role: "assistant" },
+          parts: [{ type: "text", text: "No completion in latest message" }],
+        },
+      ]
+      const ctx = createPluginInput(messages)
+
+      // #when
+      const detected = await detectCompletionInSessionMessages(ctx, {
+        sessionID: "session-123",
+        promise: "DONE",
+        apiTimeoutMs: 1000,
+        directory: "/tmp",
+      })
+
+      // #then
+      expect(detected).toBe(true)
+    })
+  })
+})

src/hooks/ralph-loop/completion-promise-detector.ts

@@ -52,6 +52,7 @@ export async function detectCompletionInSessionMessages(
 		promise: string
 		apiTimeoutMs: number
 		directory: string
+		sinceMessageIndex?: number
 	},
 ): Promise<boolean> {
 	try {
@@ -75,7 +76,12 @@ export async function detectCompletionInSessionMessages(
 				? responseData
 				: []
 
-		const assistantMessages = (messageArray as OpenCodeSessionMessage[]).filter((msg) => msg.info?.role === "assistant")
+		const scopedMessages =
+			typeof options.sinceMessageIndex === "number" && options.sinceMessageIndex >= 0 && options.sinceMessageIndex < messageArray.length
+				? messageArray.slice(options.sinceMessageIndex)
+				: messageArray
+
+		const assistantMessages = (scopedMessages as OpenCodeSessionMessage[]).filter((msg) => msg.info?.role === "assistant")
 		if (assistantMessages.length === 0) return false
 
 		const pattern = buildPromisePattern(options.promise)

src/hooks/ralph-loop/loop-state-controller.ts

@@ -23,6 +23,7 @@ export function createLoopStateController(options: {
 			loopOptions?: {
 				maxIterations?: number
 				completionPromise?: string
+				messageCountAtStart?: number
 				ultrawork?: boolean
 				strategy?: "reset" | "continue"
 			},
@@ -34,6 +35,7 @@ export function createLoopStateController(options: {
 					loopOptions?.maxIterations ??
 					config?.default_max_iterations ??
 					DEFAULT_MAX_ITERATIONS,
+				message_count_at_start: loopOptions?.messageCountAtStart,
 				completion_promise:
 					loopOptions?.completionPromise ??
 					DEFAULT_COMPLETION_PROMISE,
@@ -93,5 +95,19 @@ export function createLoopStateController(options: {
 
 			return state
 		},
+
+		setMessageCountAtStart(sessionID: string, messageCountAtStart: number): RalphLoopState | null {
+			const state = readState(directory, stateDir)
+			if (!state || state.session_id !== sessionID) {
+				return null
+			}
+
+			state.message_count_at_start = messageCountAtStart
+			if (!writeState(directory, state, stateDir)) {
+				return null
+			}
+
+			return state
+		},
 	}
 }

src/hooks/ralph-loop/ralph-loop-event-handler.ts

@@ -84,6 +84,7 @@ export function createRalphLoopEventHandler(
 						promise: state.completion_promise,
 						apiTimeoutMs: options.apiTimeoutMs,
 						directory: options.directory,
+						sinceMessageIndex: state.message_count_at_start,
 					})
 
 				if (completionViaTranscript || completionViaApi) {

src/hooks/ralph-loop/ralph-loop-hook.ts

@@ -13,6 +13,7 @@ export interface RalphLoopHook {
     options?: {
       maxIterations?: number
       completionPromise?: string
+      messageCountAtStart?: number
       ultrawork?: boolean
       strategy?: "reset" | "continue"
     }

src/hooks/ralph-loop/storage.ts

@@ -44,6 +44,12 @@ export function readState(directory: string, customPath?: string): RalphLoopStat
       active: isActive,
       iteration: iterationNum,
       max_iterations: Number(data.max_iterations) || DEFAULT_MAX_ITERATIONS,
+      message_count_at_start:
+        typeof data.message_count_at_start === "number"
+          ? data.message_count_at_start
+          : typeof data.message_count_at_start === "string" && data.message_count_at_start.trim() !== ""
+            ? Number(data.message_count_at_start)
+            : undefined,
       completion_promise: stripQuotes(data.completion_promise) || DEFAULT_COMPLETION_PROMISE,
       started_at: stripQuotes(data.started_at) || new Date().toISOString(),
       prompt: body.trim(),
@@ -72,13 +78,17 @@ export function writeState(
     const sessionIdLine = state.session_id ? `session_id: "${state.session_id}"\n` : ""
     const ultraworkLine = state.ultrawork !== undefined ? `ultrawork: ${state.ultrawork}\n` : ""
     const strategyLine = state.strategy ? `strategy: "${state.strategy}"\n` : ""
+    const messageCountAtStartLine =
+      typeof state.message_count_at_start === "number"
+        ? `message_count_at_start: ${state.message_count_at_start}\n`
+        : ""
     const content = `---
 active: ${state.active}
 iteration: ${state.iteration}
 max_iterations: ${state.max_iterations}
 completion_promise: "${state.completion_promise}"
 started_at: "${state.started_at}"
-${sessionIdLine}${ultraworkLine}${strategyLine}---
+${sessionIdLine}${ultraworkLine}${strategyLine}${messageCountAtStartLine}---
 ${state.prompt}
 `
 

src/hooks/ralph-loop/types.ts

@@ -4,6 +4,7 @@ export interface RalphLoopState {
   active: boolean
   iteration: number
   max_iterations: number
+  message_count_at_start?: number
   completion_promise: string
   started_at: string
   prompt: string