Added test suite

tests/errors.spec.ts

@@ -0,0 +1,112 @@
+import {
+	CustomError,
+	BadRequestError,
+	UnauthorizedError,
+	PaymentRequiredError,
+	ForbiddenError,
+	NotFoundError,
+	MethodNotAllowedError,
+	NotAcceptableError,
+	InternalServerError,
+	NotImplementedError,
+	BadGatewayError,
+	ServiceUnavailableError,
+	GatewayTimeoutError,
+	errorFromCode
+} from '../src';
+
+describe('CustomError Hierarchy', () => {
+	it('CustomError basic properties and code getter/setter', () => {
+		const err = new CustomError('Test', 501);
+		expect(err.message).toBe('Test');
+		expect(err.code).toBe(501);
+		err.code = 404;
+		expect(err.code).toBe(404);
+		// default code if not provided
+		const noCodeError = new CustomError('No code');
+		expect(noCodeError.code).toBe(500);
+	});
+
+	it('CustomError static from method copies properties and stack', () => {
+		const orig: any = new Error('oops');
+		orig.code = 402;
+		orig.stack = 'FAKE_STACK';
+		const custom = CustomError.from(orig);
+		expect(custom).toBeInstanceOf(CustomError);
+		expect(custom.message).toBe('oops');
+		expect(custom.code).toBe(500);
+		expect(custom.stack).toBe('FAKE_STACK');
+	});
+
+	it('CustomError instanceof works', () => {
+		expect(CustomError.instanceof(new CustomError())).toBe(true);
+		expect(CustomError.instanceof(new Error())).toBe(false);
+	});
+
+	it('CustomError toString returns message', () => {
+		const err = new CustomError('foo');
+		expect(err.toString()).toBe('foo');
+	});
+
+	const cases = [
+		[BadRequestError, 400, 'Bad Request'],
+		[UnauthorizedError, 401, 'Unauthorized'],
+		[PaymentRequiredError, 402, 'Payment Required'],
+		[ForbiddenError, 403, 'Forbidden'],
+		[NotFoundError, 404, 'Not Found'],
+		[MethodNotAllowedError, 405, 'Method Not Allowed'],
+		[NotAcceptableError, 406, 'Not Acceptable'],
+		[InternalServerError, 500, 'Internal Server Error'],
+		[NotImplementedError, 501, 'Not Implemented'],
+		[BadGatewayError, 502, 'Bad Gateway'],
+		[ServiceUnavailableError, 503, 'Service Unavailable'],
+		[GatewayTimeoutError, 504, 'Gateway Timeout'],
+	] as const;
+
+	describe.each(cases)(
+		'%p (code=%i, defaultMessage="%s")',
+		(ErrClass, code, defMsg) => {
+			it('has static code, default message, and instanceof', () => {
+				const e = new ErrClass();
+				expect(e).toBeInstanceOf(ErrClass);
+				expect(e.code).toBe(code);
+				expect(e.message).toBe(defMsg);
+				expect(ErrClass.instanceof(e)).toBe(true);
+			});
+
+			it('supports custom messages', () => {
+				const msg = 'Custom msg';
+				const e = new ErrClass(msg);
+				expect(e.message).toBe(msg);
+			});
+		}
+	);
+
+	describe('errorFromCode', () => {
+		it.each(cases)(
+			'returns %p for code %i',
+			(ErrClass, code, defMsg) => {
+				const err = errorFromCode(code);
+				expect(err).toBeInstanceOf(ErrClass);
+				expect(err.code).toBe(code);
+				expect(err.message).toBe(defMsg);
+			}
+		);
+		it('overrides message if provided', () => {
+			const err = errorFromCode(404, 'Nope');
+			expect(err).toBeInstanceOf(NotFoundError);
+			expect(err.message).toBe('Nope');
+		});
+		it('fallbacks to CustomError for unknown codes', () => {
+			const err = errorFromCode(999, 'xyz');
+			expect(err).toBeInstanceOf(CustomError);
+			expect(err.code).toBe(999);
+			expect(err.message).toBe('xyz');
+		});
+		it('handles missing message gracefully', () => {
+			const err = errorFromCode(555);
+			expect(err).toBeInstanceOf(CustomError);
+			expect(err.code).toBe(555);
+		});
+	});
+});