Q47: task parents cannot form a cycle

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/unit/task-helpers.test.ts

@@ -0,0 +1,23 @@
+import { describe, expect, test } from "vitest";
+import { descendantIds, runBlocker } from "../../src/renderer/src/pages/work/task-helpers";
+import type { ProviderRecord, TaskRecord, TaskRunRecord } from "../../src/shared/domain";
+
+const provider = { enabled: true, authState: "configured" } as ProviderRecord;
+const task = (status: TaskRecord["status"]) => ({ id: "tsk_1", status }) as TaskRecord;
+const run = (state: string, taskId = "tsk_1") => ({ taskId, state }) as TaskRunRecord;
+
+describe("work task helpers", () => {
+  test("a manual run needs a provider, an open task and no session in flight", () => {
+    expect(runBlocker(task("in_progress"), provider, [run("completed"), run("running", "tsk_other")])).toBeNull();
+    expect(runBlocker(task("in_progress"), null, [])).toBe("Connect a provider to run");
+    expect(runBlocker(task("done"), provider, [])).toBe("Done tasks do not run");
+    expect(runBlocker(task("backlog"), provider, [run("queued")])).toBe("A session is already queued or running");
+    expect(runBlocker(task("review"), provider, [run("running")])).toBe("A session is already queued or running");
+  });
+
+  test("descendants are found through every level, so the parent picker can leave them out", () => {
+    const tree = [["b", "a"], ["c", "b"], ["d", null], ["e", "c"]].map(([id, parentTaskId]) => ({ id, parentTaskId }) as TaskRecord);
+    expect([...descendantIds("a", tree)].sort()).toEqual(["b", "c", "e"]);
+    expect([...descendantIds("d", tree)]).toEqual([]);
+  });
+});