Add test for proxy error

test/setup.js

@@ -87,6 +87,9 @@ nock('http://example.com')
   .reply(302, 'redirecting ad infinitum...', {
     'Location': '/redirectloop'
   })
+
+  .get('/proxyerror')
+  .replyWithError('throw node')
 ;
 
 echoheaders('http://example.com');

test/test.js

@@ -263,6 +263,13 @@ describe('Basic functionality', function() {
       })
       .end(done);
   });
+
+  it('Proxy error', function(done) {
+    request(cors_anywhere)
+      .get('/example.com/proxyerror')
+      .expect('Access-Control-Allow-Origin', '*')
+      .expect(404, 'Not found because of proxy error: Error: throw node', done);
+  });
 });
 
 describe('server on https', function() {