fix(ipc): expose classified handler codes

tests/unit/ipc-support-error-code.test.ts

@@ -0,0 +1,89 @@
+import type { IpcMainInvokeEvent } from "electron";
+import { z } from "zod";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import type { DesktopResult } from "@shared/contracts";
+
+const { ipcHandlers, ipcHandle } = vi.hoisted(() => {
+  const handlers = new Map<string, (event: IpcMainInvokeEvent, ...args: unknown[]) => Promise<DesktopResult<unknown>>>();
+  return {
+    ipcHandlers: handlers,
+    ipcHandle: vi.fn((channel: string, handler: (event: IpcMainInvokeEvent, ...args: unknown[]) => Promise<DesktopResult<unknown>>) => {
+      handlers.set(channel, handler);
+    }),
+  };
+});
+
+vi.mock("electron", () => ({
+  ipcMain: {
+    handle: ipcHandle,
+  },
+  Notification: {
+    isSupported: () => false,
+  },
+}));
+
+import { createIpcSupport } from "../../src/main/ipc-support";
+
+describe("IPC support error codes", () => {
+  beforeEach(() => {
+    ipcHandlers.clear();
+    ipcHandle.mockClear();
+  });
+
+  it("returns the classified handler code without leaking the raw exception message", async () => {
+    const { registerHandle } = createSupport();
+    registerHandle("test:throws", () => {
+      throw new Error("database password leaked in raw error");
+    });
+
+    const result = await invokeRegisteredHandler("test:throws");
+
+    expect(result).toEqual({
+      ok: false,
+      error: {
+        code: "ipc.handler.failed",
+        message: "The desktop operation failed. Use the error code when reporting this issue.",
+      },
+    });
+  });
+
+  it("returns the classified payload code for zod validation failures", async () => {
+    const { registerHandle } = createSupport();
+    registerHandle("test:payload", () => {
+      z.object({ name: z.string() }).parse({ name: 42 });
+      return { ok: true, data: true };
+    });
+
+    const result = await invokeRegisteredHandler("test:payload");
+
+    expect(result).toEqual({
+      ok: false,
+      error: {
+        code: "ipc.payload.invalid",
+        message: "The desktop request payload is invalid.",
+      },
+    });
+  });
+});
+
+function createSupport() {
+  return createIpcSupport({
+    isDev: true,
+    devServerOrigin: "http://localhost:5173",
+    logger: { error: vi.fn() },
+    getMainWindow: () => null,
+    getDb: () => ({
+      hasCompany: () => true,
+      belongsToCompany: () => true,
+    }),
+  });
+}
+
+async function invokeRegisteredHandler(channel: string): Promise<DesktopResult<unknown>> {
+  const handler = ipcHandlers.get(channel);
+  if (!handler) throw new Error(`No IPC handler registered for ${channel}.`);
+  return handler({
+    senderFrame: { url: "http://localhost:5173/app" },
+    sender: { getURL: () => "http://localhost:5173/app" },
+  } as IpcMainInvokeEvent);
+}