gh-marcioaltoe-claude-craftkit-plugins-quality/commands/create-test.md

description

description
Create a test file for a function, class, or API route

Create Test

Generate a test file using Vitest for functions, classes, or API routes.

Instructions

1. Ask what to test:
   • Utility function or class
   • API route (Hono)
   • Domain logic
   • Integration test
2. Create test file following naming convention:
   • *.test.ts or *.test.tsx
   • Co-located with source file in __tests__/ folder (unit tests)
   • Or in root-level tests/ directory (integration/E2E tests)
3. Generate test with:
   • Proper imports from vitest
   • describe block for test suite
   • Individual test cases with it()
   • Setup and teardown if needed (beforeEach, afterEach)
   • Mock implementations using vi.fn() from Vitest
   • Clear assertions with expect()
4. For utilities and classes, test:
   • Input/output correctness
   • Edge cases
   • Error handling
   • Type safety
5. For API routes (Hono), test:
   • Request/response handling
   • Authentication/authorization
   • Status codes
   • Error responses

Unit Test Example

import { describe, expect, it } from "vitest";
import { calculateDiscount } from "./discount";

describe("calculateDiscount", () => {
  it("calculates 10% discount correctly", () => {
    const result = calculateDiscount(100, 10);
    expect(result).toBe(90);
  });

  it("returns original price when discount is 0", () => {
    const result = calculateDiscount(100, 0);
    expect(result).toBe(100);
  });

  it("throws error for invalid discount percentage", () => {
    expect(() => calculateDiscount(100, 150)).toThrow("Invalid discount");
  });
});

API Route Test Example (Hono)

import { describe, expect, it, vi } from "vitest";
import { Hono } from "hono";

describe("Contract: POST /users", () => {
  it("creates a user and returns 201", async () => {
    const app = new Hono();
    const createMock = vi.fn(async () => ({ id: "123", name: "John" }));

    app.post("/users", async (c) => {
      const body = await c.req.json();
      const user = await createMock(body);
      return c.json(user, 201);
    });

    const response = await app.request("/users", {
      method: "POST",
      headers: { "content-type": "application/json" },
      body: JSON.stringify({ name: "John" }),
    });

    expect(createMock).toHaveBeenCalledTimes(1);
    expect(response.status).toBe(201);
    const body = await response.json();
    expect(body.id).toBe("123");
  });

  it("returns 401 when unauthorized", async () => {
    const app = new Hono();

    app.post("/users", (c) => c.json({ error: "Unauthorized" }, 401));

    const response = await app.request("/users", {
      method: "POST",
    });

    expect(response.status).toBe(401);
  });
});

Running Tests

# Run all tests
bun run test

# Run tests in watch mode
bun run test:watch

# Run specific test file
bun run test path/to/test.test.ts

# Run with coverage
bun run test:coverage

Ensure comprehensive test coverage with meaningful assertions and proper error handling.