A Sane Frontend Testing Setup

Test the contract, not the implementation

Good tests describe behavior a user (or another module) relies on.

import { describe, it, expect } from "vitest";

describe("formatPrice", () => {
  it("adds a currency symbol", () => {
    expect(formatPrice(1200)).toBe("$1,200");
  });
});

Keep the fast unit tests close to the code and reserve slower end-to-end runs for critical flows.

Edit this post to match your own testing philosophy.