webchat: show real ws errors

test/format-error.test.ts

@@ -0,0 +1,30 @@
+import { describe, expect, it } from "vitest";
+import { formatError } from "../apps/macos/Sources/Clawdis/Resources/WebChat/format-error.js";
+
+describe("formatError", () => {
+  it("handles Error with stack", () => {
+    const err = new Error("boom");
+    err.stack = "stack trace";
+    expect(formatError(err)).toBe("stack trace");
+  });
+
+  it("handles CloseEvent-like object", () => {
+    const err = { code: 1006, reason: "socket closed", wasClean: false };
+    expect(formatError(err)).toBe("WebSocket closed (1006); reason: socket closed");
+  });
+
+  it("handles WebSocket error event with state", () => {
+    const err = { type: "error", target: { readyState: 2 } };
+    expect(formatError(err)).toBe("WebSocket error (state: closing)");
+  });
+
+  it("stringifies plain objects", () => {
+    expect(formatError({ a: 1 })).toBe("{\"a\":1}");
+  });
+
+  it("falls back to string", () => {
+    const circular = {} as any;
+    circular.self = circular;
+    expect(formatError(circular)).toBe("[object Object]");
+  });
+});