fix: Correct behavior when other libraries override http.get and http…

….request (#1868)

Thanks @kennethaasan for finding this fix!

Fix #1836

lib/common.js

@@ -99,7 +99,11 @@ function overrideRequests(newRequest) {
     }
     // https://nodejs.org/api/http.html#http_http_get_options_callback
     module.get = function(input, options, callback) {
-      const req = module.request(input, options, callback)
+      const req = newRequest(proto, overriddenGet.bind(module), [
+        input,
+        options,
+        callback,
+      ])
       req.end()
       return req
     }

tests/test_request_overrider.js

@@ -684,3 +684,60 @@ test('Request with `Expect: 100-continue` triggers continue event', t => {
     req.end(exampleRequestBody)
   })
 })
+
+// https://github.com/nock/nock/issues/1836
+test('when http.get and http.request have been overridden before nock overrides them, http.get calls through to the expected method', async t => {
+  // TODO Investigate why this is needed when it's also in the `afterEach()`
+  // hook in ./setup.
+  t.on('end', () => {
+    nock.restore()
+    sinon.restore()
+  })
+
+  // Obtain the original `http.request()` and stub it out, as a library might.
+  nock.restore()
+  const overriddenRequest = sinon.stub(http, 'request').callThrough()
+  const overriddenGet = sinon.stub(http, 'get').callThrough()
+
+  // Let Nock override them again.
+  nock.activate()
+
+  const server = http.createServer((request, response) => {
+    response.writeHead(200)
+    response.end()
+  })
+  await new Promise(resolve => server.listen(resolve))
+
+  const req = http.get(`http://localhost:${server.address().port}`)
+  expect(overriddenGet).to.have.been.calledOnce()
+  expect(overriddenRequest).not.to.have.been.called()
+
+  req.abort()
+  server.close()
+})
+
+// https://github.com/nock/nock/issues/1836
+test('when http.get and http.request have been overridden before nock overrides them, http.request calls through to the expected method', async t => {
+  t.on('end', () => {
+    nock.restore()
+    sinon.restore()
+  })
+
+  // Obtain the original `http.request()` and stub it out, as a library might.
+  nock.restore()
+  const overriddenRequest = sinon.stub(http, 'request').callThrough()
+  const overriddenGet = sinon.stub(http, 'get').callThrough()
+
+  // Let Nock override them again.
+  nock.activate()
+
+  const req = http.request({
+    host: 'localhost',
+    path: '/',
+    port: 1234,
+  })
+  expect(overriddenRequest).to.have.been.calledOnce()
+  expect(overriddenGet).not.to.have.been.called()
+
+  req.abort()
+})