import { describe, it, expect } from 'vitest';
import { createMocks } from './mock.ts';
import { MockReadable, MockWritable } from './stdio.ts';

describe('createMocks', () => {
	it('returns undefined streams when not requested', () => {
		const mocks = createMocks();
		expect(mocks.input).toBeUndefined();
		expect(mocks.output).toBeUndefined();
	});

	it('creates input stream with `true`', () => {
		const mocks = createMocks({ input: true });
		expect(mocks.input).toBeInstanceOf(MockReadable);
	});

	it('creates output stream with `true`', () => {
		const mocks = createMocks({ output: true });
		expect(mocks.output).toBeInstanceOf(MockWritable);
	});

	it('passes config to output stream', () => {
		const mocks = createMocks({ output: { columns: 120, rows: 40, isTTY: true } });
		expect(mocks.output.columns).toBe(120);
		expect(mocks.output.rows).toBe(40);
		expect(mocks.output.isTTY).toBe(true);
	});

	it('passes config to input stream', () => {
		const mocks = createMocks({ input: { isTTY: true } });
		expect(mocks.input.isTTY).toBe(true);
	});

	it('stubs env vars for duration of test', () => {
		createMocks({ env: { TEST_MOCK_VAR: 'hello' } });
		expect(process.env.TEST_MOCK_VAR).toBe('hello');
	});

	it('restores env vars after test finishes', async () => {
		// Previous test's onTestFinished should have cleaned up
		expect(process.env.TEST_MOCK_VAR).toBeUndefined();
	});
});