test: add tests for SelectPrompt

packages/core/test/prompts/select.test.ts

@@ -0,0 +1,105 @@
+import color from 'picocolors';
+import { cursor } from 'sisteransi';
+import { afterEach, beforeEach, describe, expect, test, vi } from 'vitest';
+import { default as SelectPrompt } from '../../src/prompts/select.js';
+import { MockReadable } from '../mock-readable.js';
+import { MockWritable } from '../mock-writable.js';
+
+describe('SelectPrompt', () => {
+	let input: MockReadable;
+	let output: MockWritable;
+
+	beforeEach(() => {
+		input = new MockReadable();
+		output = new MockWritable();
+	});
+
+	afterEach(() => {
+		vi.restoreAllMocks();
+	});
+
+	test('renders render() result', () => {
+		const instance = new SelectPrompt({
+			input,
+			output,
+			render: () => 'foo',
+			options: [{ value: 'foo' }, { value: 'bar' }],
+		});
+		instance.prompt();
+		expect(output.buffer).to.deep.equal([cursor.hide, 'foo']);
+	});
+
+	describe('cursor', () => {
+		test('cursor is index of selected item', () => {
+			const instance = new SelectPrompt({
+				input,
+				output,
+				render: () => 'foo',
+				options: [{ value: 'foo' }, { value: 'bar' }],
+			});
+
+			instance.prompt();
+
+			expect(instance.cursor).to.equal(0);
+			input.emit('keypress', 'down', { name: 'down' });
+			expect(instance.cursor).to.equal(1);
+		});
+
+		test('cursor loops around', () => {
+			const instance = new SelectPrompt({
+				input,
+				output,
+				render: () => 'foo',
+				options: [{ value: 'foo' }, { value: 'bar' }, { value: 'baz' }],
+			});
+
+			instance.prompt();
+
+			expect(instance.cursor).to.equal(0);
+			input.emit('keypress', 'up', { name: 'up' });
+			expect(instance.cursor).to.equal(2);
+			input.emit('keypress', 'down', { name: 'down' });
+			expect(instance.cursor).to.equal(0);
+		});
+
+		test('left behaves as up', () => {
+			const instance = new SelectPrompt({
+				input,
+				output,
+				render: () => 'foo',
+				options: [{ value: 'foo' }, { value: 'bar' }, { value: 'baz' }],
+			});
+
+			instance.prompt();
+
+			input.emit('keypress', 'left', { name: 'left' });
+			expect(instance.cursor).to.equal(2);
+		});
+
+		test('right behaves as down', () => {
+			const instance = new SelectPrompt({
+				input,
+				output,
+				render: () => 'foo',
+				options: [{ value: 'foo' }, { value: 'bar' }],
+			});
+
+			instance.prompt();
+
+			input.emit('keypress', 'left', { name: 'left' });
+			expect(instance.cursor).to.equal(1);
+		});
+
+		test('initial value is selected', () => {
+			const instance = new SelectPrompt({
+				input,
+				output,
+				render: () => 'foo',
+				options: [{ value: 'foo' }, { value: 'bar' }],
+				initialValue: 'bar',
+			});
+			instance.prompt();
+			expect(instance.cursor).to.equal(1);
+		});
+	});
+});