FIX: Ensure all arguments are passed to base fetch function

This is not a great fix; it ignores that method is only inspected when it's
in the first fetch() parameter, and it glosses over the fact that the
navigator object, for historical reasons, is very constrained in the
responses it gives (which is why the code snagged jsdom in the first
place).

It does, however, solve my immediate need of getting fetch-mock to
interoperate with jsdom.

Fixes wheresrhys#608

src/lib/fetch-handler.js

@@ -31,11 +31,11 @@ const patchNativeFetchForSafari = (nativeFetch) => {
 		return nativeFetch;
 	}
 	// It seems the code is working on Safari thus patch native fetch to avoid the error.
-	return async (request) => {
+	return async (request, ...args) => {
 		const { method } = request;
 		if (!['POST', 'PUT', 'PATCH'].includes(method)) {
 			// No patch is required in this case
-			return nativeFetch(request);
+			return nativeFetch(request, ...args);
 		}
 		const body = await request.clone().text();
 		const {

test/specs/config/safari.test.js

@@ -0,0 +1,41 @@
+const chai = require('chai');
+const expect = chai.expect;
+
+const { fetchMock, theGlobal } = testGlobals;
+
+describe('Safari override', () => {
+	beforeEach(() => {
+		fetchMock.createInstance();
+	});
+
+	it('passes all GET arguments to next function when not under Safari', async () => {
+		theGlobal.fetch = async (...args) => {
+			expect(args[0]).to.equal('http://mocked.com/');
+			expect(args[1]).to.deep.equal({ method: 'GET' });
+			return { status: 202 };
+		};
+		fetchMock.spy('http://mocked.com');
+		const res = await fetchMock.fetchHandler('http://mocked.com', {
+			method: 'GET',
+		});
+		expect(res.status).to.equal(202);
+		fetchMock.restore();
+		delete theGlobal.fetch;
+	});
+
+	it('passes all GET arguments to next function under Safari', async () => {
+		theGlobal.navigator = { vendor: 'Apple Computer, Inc.' };
+		theGlobal.fetch = async (...args) => {
+			expect(args[0]).to.equal('http://mocked.com/');
+			expect(args[1]).to.deep.equal({ method: 'GET' });
+			return { status: 202 };
+		};
+		fetchMock.spy('http://mocked.com');
+		const res = await fetchMock.fetchHandler('http://mocked.com', {
+			method: 'GET',
+		});
+		expect(res.status).to.equal(202);
+		fetchMock.restore();
+		delete theGlobal.fetch;
+	});
+});