Phase 12: manual compaction defer clear — SPEC §16.5, §12.3.

Stale pendingReinject from auto compaction is blocked until the next user prompt after manual /compact with default settings; a later auto compaction resets the clear flag.

Co-authored-by: Cursor <cursoragent@cursor.com>

test/reinject-manual-defer.test.ts

@@ -0,0 +1,75 @@
+import { describe, expect, it } from "vitest";
+import {
+	consumeCompactionOnSessionCompact,
+	createCompactionRuntime,
+} from "../src/compaction";
+import { clearPendingReinjectOnUserPrompt, tryConsumeDeferredReinject } from "../src/reinject";
+import { createDefaultSettings } from "../src/settings";
+import { createInitialState } from "../src/state";
+
+describe("manual compaction defer clear", () => {
+	it("schedules clear on manual compaction when reinjectOnManualCompaction is false", () => {
+		const runtime = createCompactionRuntime();
+		const state = createInitialState();
+		state.pendingReinject = ["alpha"];
+		runtime.pendingCompactionSource = "manual";
+
+		const shouldReinject = consumeCompactionOnSessionCompact(runtime, state, null, createDefaultSettings());
+
+		expect(shouldReinject).toBe(false);
+		expect(runtime.clearPendingReinjectOnNextUserInput).toBe(true);
+		expect(state.pendingReinject).toEqual(["alpha"]);
+	});
+
+	it("blocks deferred inject until user prompt clears stale pending", () => {
+		const runtime = createCompactionRuntime();
+		const state = createInitialState();
+		state.pendingReinject = ["alpha"];
+		runtime.clearPendingReinjectOnNextUserInput = true;
+
+		expect(
+			tryConsumeDeferredReinject(state, createDefaultSettings(), [], undefined, runtime),
+		).toBeUndefined();
+		expect(state.pendingReinject).toEqual(["alpha"]);
+	});
+
+	it("clears pending on user prompt and allows deferred inject again", () => {
+		const runtime = createCompactionRuntime();
+		const state = createInitialState();
+		state.pendingReinject = ["alpha"];
+		runtime.clearPendingReinjectOnNextUserInput = true;
+
+		expect(clearPendingReinjectOnUserPrompt(state, runtime)).toBe(true);
+		expect(state.pendingReinject).toEqual([]);
+		expect(runtime.clearPendingReinjectOnNextUserInput).toBe(false);
+	});
+
+	it("does not schedule clear when manual compaction may reinject", () => {
+		const runtime = createCompactionRuntime();
+		const state = createInitialState();
+		state.pendingReinject = ["alpha"];
+		runtime.pendingCompactionSource = "manual";
+		const settings = createDefaultSettings();
+		settings.reinjectOnManualCompaction = true;
+
+		const shouldReinject = consumeCompactionOnSessionCompact(runtime, state, true, settings);
+
+		expect(shouldReinject).toBe(true);
+		expect(runtime.clearPendingReinjectOnNextUserInput).toBe(false);
+	});
+
+	it("clears stale manual flag when a later auto compaction enqueues reinject", () => {
+		const runtime = createCompactionRuntime();
+		const state = createInitialState();
+		runtime.clearPendingReinjectOnNextUserInput = true;
+		state.pendingReinject = ["beta"];
+		runtime.pendingCompactionSource = "auto";
+
+		const shouldReinject = consumeCompactionOnSessionCompact(runtime, state, true, createDefaultSettings());
+
+		expect(shouldReinject).toBe(true);
+		expect(runtime.clearPendingReinjectOnNextUserInput).toBe(false);
+		expect(clearPendingReinjectOnUserPrompt(state, runtime)).toBe(false);
+		expect(state.pendingReinject).toEqual(["beta"]);
+	});
+});