test: add coverage for messageMode, stateMapper branches, and initStatsListener

src/lib/stores/clipboard.test.ts

@@ -19,7 +19,6 @@
  * - [ ] Search query filters by content, language, and source
  */
 
-/* eslint-disable max-lines-per-function -- Test suites naturally have many cases */
 import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
 
 // Mirror: detectLanguage from clipboard.ts

src/lib/stores/stats.test.ts

@@ -1,5 +1,7 @@
-import { describe, it, expect, beforeEach, vi } from "vitest";
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
 import { get } from "svelte/store";
+import { listen } from "@tauri-apps/api/event";
+import { invoke } from "@tauri-apps/api/core";
 import {
   stats,
   formattedStats,
@@ -13,6 +15,7 @@ import {
   getBudgetStatusMessage,
   getRemainingTokenBudget,
   getRemainingCostBudget,
+  initStatsListener,
 } from "./stats";
 import type { UsageStats, ToolTokenStats, BudgetStatus } from "./stats";
 
@@ -34,6 +37,12 @@ vi.mock("@tauri-apps/api/core", () => ({
   invoke: vi.fn(),
 }));
 
+vi.mock("./costTracking", () => ({
+  costTrackingStore: {
+    refresh: vi.fn().mockResolvedValue([]),
+  },
+}));
+
 describe("stats store", () => {
   beforeEach(() => {
     // Reset stats to default before each test
@@ -801,4 +810,85 @@ describe("stats store", () => {
       expect(getRemainingCostBudget(baseStats, 0.2)).toBe(0);
     });
   });
+
+  describe("initStatsListener", () => {
+    const emptyStats: UsageStats = {
+      total_input_tokens: 0,
+      total_output_tokens: 0,
+      total_cost_usd: 0,
+      session_input_tokens: 0,
+      session_output_tokens: 0,
+      session_cost_usd: 0,
+      model: null,
+      messages_exchanged: 0,
+      session_messages_exchanged: 0,
+      code_blocks_generated: 0,
+      session_code_blocks_generated: 0,
+      files_edited: 0,
+      session_files_edited: 0,
+      files_created: 0,
+      session_files_created: 0,
+      tools_usage: {},
+      session_tools_usage: {},
+      session_duration_seconds: 0,
+      context_tokens_used: 0,
+      context_window_limit: 200000,
+      context_utilisation_percent: 0,
+      potential_cache_hits: 0,
+      potential_cache_savings_tokens: 0,
+    };
+
+    afterEach(() => {
+      vi.resetAllMocks();
+    });
+
+    it("registers a listener for the claude:stats event", async () => {
+      vi.mocked(listen).mockResolvedValue(vi.fn());
+      vi.mocked(invoke).mockResolvedValue(emptyStats);
+
+      await initStatsListener();
+
+      expect(listen).toHaveBeenCalledWith("claude:stats", expect.any(Function));
+    });
+
+    it("updates the stats store when the listener callback fires", async () => {
+      let capturedCallback: ((event: unknown) => void) | undefined;
+      vi.mocked(listen).mockImplementation(async (_event, callback) => {
+        capturedCallback = callback as (event: unknown) => void;
+        return () => {};
+      });
+      vi.mocked(invoke).mockResolvedValue(emptyStats);
+
+      await initStatsListener();
+
+      const newStats = { ...emptyStats, total_input_tokens: 9999 };
+      capturedCallback!({ payload: { stats: newStats } });
+
+      expect(get(stats).total_input_tokens).toBe(9999);
+    });
+
+    it("loads persisted stats from the backend on initialisation", async () => {
+      const persistedStats = { ...emptyStats, total_input_tokens: 5000 };
+      vi.mocked(listen).mockResolvedValue(vi.fn());
+      vi.mocked(invoke).mockResolvedValue(persistedStats);
+
+      await initStatsListener();
+
+      expect(invoke).toHaveBeenCalledWith("get_persisted_stats");
+      expect(get(stats).total_input_tokens).toBe(5000);
+    });
+
+    it("handles a failed invoke gracefully and logs the error", async () => {
+      const error = new Error("Failed to get stats");
+      vi.mocked(listen).mockResolvedValue(vi.fn());
+      vi.mocked(invoke).mockRejectedValue(error);
+
+      const consoleErrorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+
+      await initStatsListener();
+
+      expect(consoleErrorSpy).toHaveBeenCalledWith("Failed to load initial stats:", error);
+      consoleErrorSpy.mockRestore();
+    });
+  });
 });