index.test.mjs

import fetch from "../src/index.mjs";
import fetchDist from "..";

describe("unfetch", () => {
	it("should be a function", () => {
		expect(fetch).toEqual(expect.any(Function));
	});

	it("should be compiled correctly", () => {
		expect(fetchDist).toEqual(expect.any(Function));
		expect(fetchDist).toHaveLength(2);
	});

	describe("fetch()", () => {
		let xhr;

		beforeEach(() => {
			xhr = {
				setRequestHeader: jest.fn(),
				getAllResponseHeaders: jest
					.fn()
					.mockReturnValue(
						"X-Foo: bar\r\nX-Foo: baz\r\nX-Bar: bar, baz\r\nx-test: \r\nX-Baz: bar, baz\r\ndate: 18:23:22"
					),
				getResponseHeader: jest.fn().mockReturnValue("bar, baz"),
				open: jest.fn(),
				send: jest.fn(),
				status: 200,
				statusText: "OK",
				responseText: '{"a":"b"}',
				responseURL: "/foo?redirect",
			};

			global.XMLHttpRequest = jest.fn(() => xhr);
		});

		afterEach(() => {
			delete global.XMLHttpRequest;
		});

		it("sanity test", () => {
			let p = fetch("/foo", { headers: { a: "b" } })
				.then((r) => {
					expect(r).toMatchObject({
						text: expect.any(Function),
						json: expect.any(Function),
						blob: expect.any(Function),
						clone: expect.any(Function),
						headers: expect.any(Object),
					});
					expect(r.clone()).not.toBe(r);
					expect(r.clone().url).toEqual("/foo?redirect");
					expect(r.headers.get).toEqual(expect.any(Function));
					expect(r.headers.get("x-foo")).toEqual("bar, baz");
					expect(r.headers.keys()).toEqual([
						"x-foo",
						"x-bar",
						"x-test",
						"x-baz",
						"date",
					]);
					return r.json();
				})
				.then((data) => {
					expect(data).toEqual({ a: "b" });

					expect(xhr.setRequestHeader).toHaveBeenCalledTimes(1);
					expect(xhr.setRequestHeader).toHaveBeenCalledWith("a", "b");
					expect(xhr.open).toHaveBeenCalledTimes(1);
					expect(xhr.open).toHaveBeenCalledWith("get", "/foo", true);
					expect(xhr.send).toHaveBeenCalledTimes(1);
					expect(xhr.send).toHaveBeenCalledWith(null);
				});

			expect(xhr.onload).toEqual(expect.any(Function));
			expect(xhr.onerror).toEqual(expect.any(Function));

			xhr.onload();

			return p;
		});

		it("handles empty header values", () => {
			xhr.getAllResponseHeaders = jest
				.fn()
				.mockReturnValue("Server: \nX-Foo:baz");
			const headers = {
				server: "",
				"x-foo": "baz",
			};
			xhr.getResponseHeader = jest.fn(
				(header) => headers[header.toLowerCase()] ?? null
			);
			let p = fetch("/foo").then((r) => {
				expect(r.headers.get("server")).toEqual("");
				expect(r.headers.get("X-foo")).toEqual("baz");
			});

			xhr.onload();

			return p;
		});
	});
});