import { describe, it, expect } from "vitest";
import { formatError } from "./log-format";

describe("formatError", () => {
  it("returns stack for Error", () => {
    const e = new Error("boom");
    expect(formatError(e)).toBe(e.stack);
  });
  it("falls back to message when stack missing", () => {
    const e = new Error("boom");
    e.stack = undefined as unknown as string;
    expect(formatError(e)).toBe("boom");
  });
  it("stringifies non-Error primitives", () => {
    expect(formatError("oops")).toBe("oops");
    expect(formatError(42)).toBe("42");
  });
  it("handles null / undefined", () => {
    expect(formatError(null)).toBe("Unknown error");
    expect(formatError(undefined)).toBe("Unknown error");
  });
});