the-collective-hub/.github/prompts/test-coverage.prompt.md

agent, description

agent	description
agent	Analyse test coverage gaps for a file or directory and generate missing tests

You are performing test coverage analysis and generating missing tests for The Collective Hub project.

Your task

The user has provided one or more source files or a directory to analyse. For each file:

1. Read the source file
2. Identify all exported functions, components, handlers, and branches that lack test coverage
3. Check whether a co-located test file already exists
4. Generate or extend the test file to cover the gaps

If the user has not specified a file, ask them to provide one before proceeding.

---

Coverage analysis checklist

For each source file, enumerate all of the following that need tests:

Server files (*.server.ts, +server.ts, +page.server.ts)

• Every exported load function — success path, unauthenticated redirect, DB error
• Every form action — valid input, fail() path, redirect path
• Every HTTP handler (GET, POST, PATCH, DELETE) — 2xx and 4xx/5xx paths
• Auth guard branches — unauthenticated (locals.user is null), insufficient role
• Query results — empty array, single result, multiple results

Svelte components (*.svelte)

• Default render with required props
• Every {#if} branch (both true and false)
• Every {#each} branch — empty array, non-empty array
• User interactions — click, input, form submit
• Conditional class/style variations driven by props
• Slot/snippet presence and absence (note as limitation if not testable)

Utility / library files (*.ts)

• Every exported function — happy path
• Edge cases: empty input, null/undefined, boundary values
• Error paths: thrown errors, returned error objects

---

File placement rules

Source file	Test file
src/lib/utils/format.ts	src/lib/utils/format.test.ts
src/lib/components/ui/ServiceCard.svelte	src/lib/components/ui/ServiceCard.svelte.test.ts
src/routes/api/contact/+server.ts	src/routes/api/contact/server.test.ts
src/routes/(app)/services/+page.server.ts	src/routes/(app)/services/page.server.test.ts

Drop the + prefix for route test files — SvelteKit errors on +server.test.ts at build time. Server tests use .test.ts; component tests use .svelte.test.ts.

---

Mocking rules

Always mock the database

vi.mock is hoisted before const declarations. Always use vi.hoisted() for mock functions referenced inside vi.mock factories:

const { mockFindMany, mockInsert } = vi.hoisted(() => ({
	mockFindMany: vi.fn(),
	mockInsert: vi.fn()
}));

vi.mock('$lib/server/db', () => ({
	db: {
		query: {
			services: { findMany: mockFindMany, findFirst: vi.fn() }
		},
		insert: mockInsert
	}
}));

Reset mocks in beforeEach:

beforeEach(() => {
	vi.clearAllMocks();
});

Create a mock RequestEvent for +server.ts handlers

function mockEvent(overrides: Partial<RequestEvent> = {}): RequestEvent {
	return {
		request: new Request('http://localhost/api/resource', { method: 'GET' }),
		locals: { user: { id: 'user-1', role: 'user' } },
		params: {},
		url: new URL('http://localhost/api/resource'),
		...overrides
	} as unknown as RequestEvent;
}

Create a mock PageServerLoadEvent for load functions

function mockLoadEvent(overrides = {}) {
	return {
		locals: { user: { id: 'user-1', role: 'user' } },
		params: {},
		url: new URL('http://localhost/page'),
		...overrides
	} as any;
}

Stub fetch for external API calls

vi.stubGlobal(
	'fetch',
	vi.fn().mockResolvedValue(new Response(JSON.stringify({ data: [] }), { status: 200 }))
);

---

Test structure

import { describe, it, expect, vi, beforeEach } from 'vitest';

// mocks before imports that use them
const { mockFn } = vi.hoisted(() => ({ mockFn: vi.fn() }));
vi.mock('$lib/server/db', () => ({ db: { query: { table: { findMany: mockFn } } } }));

import { myFunction } from './myModule';

describe('myFunction', () => {
	beforeEach(() => {
		vi.clearAllMocks();
	});

	it('returns expected result for valid input', async () => {
		mockFn.mockResolvedValue([{ id: 1 }]);
		const result = await myFunction('valid');
		expect(result).toEqual({ id: 1 });
	});

	it('returns null when not found', async () => {
		mockFn.mockResolvedValue([]);
		const result = await myFunction('missing');
		expect(result).toBeNull();
	});
});

---

requireAssertions rule

expect.requireAssertions: true is set globally. Every it block must contain at least one expect() or the test will fail even if no error is thrown.

---

Coverage run command

After generating tests, remind the user they can check coverage with:

npm run test:run -- --coverage

The HTML report is written to coverage/index.html.

---

Output format

For each source file analysed:

1. Coverage gaps — bullet list of untested functions/branches
2. Test file path — where the new/updated test file will go
3. Generated test file — full content, ready to save

If a test file already exists, show only the new it blocks to add, not the full file.