Multiple mocks matchers

[emadolsky]

So I was writing some tests for my code. In one of my functions I was calling two APIs (for different purposes). So I needed to have two mockers. one of them(route2) should have had a matcher for the request body while the other (route1) did not. (For this, I had make two mockers with gock.New) Then I traced an unexpected behavior. When I was calling the API to route2, the matcher registered on route1 mocker was being called. Therefore, I looked up in the code to see the reason and I found out that there was a global variable named "Matchers" in "matcher.go". And this causes all the mockers to have the same matchers which I believe is a bug. My test code:

	//route1
	gock.New("http://emad.host").
		Get("/notifications/bucketname").
		Reply(200).
		JSON(map[string]interface{}{
		"ok": "ok",
	})
	//route2
	gock.New("http://emad.host").
		Put("/notifications/bucketname").
		AddMatcher(func(r *http.Request, request *gock.Request) (bool, error) {
		fmt.Println("matcher called")
		return true, nil
	}).Reply(400)

	client := &http.Client{}

	//this request would call matcher of route2 (unexpected behaviour)
	request1, _ := http.NewRequest("GET", "http://emad.host/notifications/bucketname", nil)
	fmt.Println(client.Do(request1))

	request2, _ := http.NewRequest("PUT", "http://emad.host/notifications/bucketname", bytes.NewReader([]byte(`hello world`)))
	fmt.Println(client.Do(request2))

[h2non]

This is something that has been discussed previuosly here: https://github.com/h2non/gock/pull/26

You are very welcome to contribute. I'm open to include this capability. I have implemented it in pook and I'm relatively happy with that design decision.

[danny-cheung]

This is a variation of #20 and is fixed by pr #55