From fd1ba2c7feaedb78e5d87107f6e6a274044121b8 Mon Sep 17 00:00:00 2001
From: Armin Ronacher <armin.ronacher@active-4.com>
Date: Thu, 18 Jun 2026 23:15:18 +0200
Subject: [PATCH] test(coding-agent): seed auto-compaction queue fixture

---
 ...gent-session-auto-compaction-queue.test.ts | 103 ++++++++++--------
 1 file changed, 59 insertions(+), 44 deletions(-)

diff --git a/packages/coding-agent/test/agent-session-auto-compaction-queue.test.ts b/packages/coding-agent/test/agent-session-auto-compaction-queue.test.ts
index 1abe3e28..7fd56b46 100644
--- a/packages/coding-agent/test/agent-session-auto-compaction-queue.test.ts
+++ b/packages/coding-agent/test/agent-session-auto-compaction-queue.test.ts
@@ -2,7 +2,12 @@ import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { Agent } from "@earendil-works/pi-agent-core";
-import { type AssistantMessage, getModel } from "@earendil-works/pi-ai";
+import {
+	type AssistantMessage,
+	createAssistantMessageEventStream,
+	fauxAssistantMessage,
+	getModel,
+} from "@earendil-works/pi-ai";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { AgentSession } from "../src/core/agent-session.ts";
 import { AuthStorage } from "../src/core/auth-storage.ts";
@@ -11,51 +16,10 @@ import { SessionManager } from "../src/core/session-manager.ts";
 import { SettingsManager } from "../src/core/settings-manager.ts";
 import { createTestResourceLoader } from "./utilities.ts";
 
-vi.mock("../src/core/compaction/index.js", () => ({
-	calculateContextTokens: (usage: {
-		input: number;
-		output: number;
-		cacheRead: number;
-		cacheWrite: number;
-		totalTokens?: number;
-	}) => usage.totalTokens ?? usage.input + usage.output + usage.cacheRead + usage.cacheWrite,
-	collectEntriesForBranchSummary: () => ({ entries: [], commonAncestorId: null }),
-	compact: async () => ({
-		summary: "compacted",
-		firstKeptEntryId: "entry-1",
-		tokensBefore: 100,
-		details: {},
-	}),
-	estimateContextTokens: (
-		messages: Array<{
-			role: string;
-			usage?: { input: number; output: number; cacheRead: number; cacheWrite: number; totalTokens?: number };
-			stopReason?: string;
-		}>,
-	) => {
-		// Walk backwards to find last non-error, non-aborted assistant with usage
-		for (let i = messages.length - 1; i >= 0; i--) {
-			const msg = messages[i];
-			if (msg.role === "assistant" && msg.stopReason !== "error" && msg.stopReason !== "aborted" && msg.usage) {
-				const tokens =
-					msg.usage.totalTokens ?? msg.usage.input + msg.usage.output + msg.usage.cacheRead + msg.usage.cacheWrite;
-				return { tokens, usageTokens: tokens, trailingTokens: 0, lastUsageIndex: i };
-			}
-		}
-		return { tokens: 0, usageTokens: 0, trailingTokens: 0, lastUsageIndex: null };
-	},
-	generateBranchSummary: async () => ({ summary: "", aborted: false, readFiles: [], modifiedFiles: [] }),
-	prepareCompaction: () => ({ dummy: true }),
-	shouldCompact: (
-		contextTokens: number,
-		contextWindow: number,
-		settings: { enabled: boolean; reserveTokens: number },
-	) => settings.enabled && contextTokens > contextWindow - settings.reserveTokens,
-}));
-
 describe("AgentSession auto-compaction queue resume", () => {
 	let session: AgentSession;
 	let sessionManager: SessionManager;
+	let settingsManager: SettingsManager;
 	let tempDir: string;
 
 	beforeEach(() => {
@@ -73,7 +37,7 @@ describe("AgentSession auto-compaction queue resume", () => {
 		});
 
 		sessionManager = SessionManager.inMemory();
-		const settingsManager = SettingsManager.create(tempDir, tempDir);
+		settingsManager = SettingsManager.create(tempDir, tempDir);
 		const authStorage = AuthStorage.create(join(tempDir, "auth.json"));
 		authStorage.setRuntimeApiKey("anthropic", "test-key");
 		const modelRegistry = ModelRegistry.create(authStorage, tempDir);
@@ -98,6 +62,57 @@ describe("AgentSession auto-compaction queue resume", () => {
 	});
 
 	it("should resume after threshold compaction when only agent-level queued messages exist", async () => {
+		settingsManager.applyOverrides({ compaction: { keepRecentTokens: 1 } });
+		const model = session.model!;
+		const now = Date.now();
+		sessionManager.appendMessage({
+			role: "user",
+			content: [{ type: "text", text: "message to compact" }],
+			timestamp: now - 1000,
+		});
+		sessionManager.appendMessage({
+			role: "assistant",
+			content: [{ type: "text", text: "assistant response to compact" }],
+			api: model.api,
+			provider: model.provider,
+			model: model.id,
+			usage: {
+				input: 100,
+				output: 0,
+				cacheRead: 0,
+				cacheWrite: 0,
+				totalTokens: 100,
+				cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+			},
+			stopReason: "stop",
+			timestamp: now - 500,
+		});
+		session.agent.state.messages = sessionManager.buildSessionContext().messages;
+		session.agent.streamFn = (summaryModel) => {
+			const stream = createAssistantMessageEventStream();
+			queueMicrotask(() => {
+				stream.push({
+					type: "done",
+					reason: "stop",
+					message: {
+						...fauxAssistantMessage("compacted"),
+						api: summaryModel.api,
+						provider: summaryModel.provider,
+						model: summaryModel.id,
+						usage: {
+							input: 10,
+							output: 0,
+							cacheRead: 0,
+							cacheWrite: 0,
+							totalTokens: 10,
+							cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+						},
+					},
+				});
+			});
+			return stream;
+		};
+
 		session.agent.followUp({
 			role: "custom",
 			customType: "test",