Gorilla Mux same endpoint multiple query params

Question

So I know that Gorilla Mux doesn't support optional query params and people suggest to create different routes with query param which makes it more solid. But in my case it is not resolving the routes as expected.

If I call /service/{locale}?param1=1,2&param2=3,4 then it invokes a.listFirst while it should call the a.listSecond and the same issue with other combinations. But:

If I keep only one route then the route works as expected. So I assume the routes itself are fine but there is some resolving issue when they are together?
If I remove the first route (the one without query param) and swap the order of the rest then they both work fine. This means the order also matters?

I know I can use request.URL.Query() to get the query params but I am curious to know why this way of defining query params as route doesn't work as expected?

a.Router.
    Methods(http.MethodGet).
    Path("/service/{locale}").
    Handler(negroni.New(
        a.contentTypeJSON,
        negroni.HandlerFunc(a.listAll),
    ))

a.Router.
    Methods(http.MethodGet).
    Path("/service/{locale}").
    Queries("param1", "{param1:[0-9,]+}").
    Handler(negroni.New(
        a.contentTypeJSON,
        negroni.HandlerFunc(a.listFirst),
    ))

a.Router.
    Methods(http.MethodGet).
    Path("/service/{locale}").
    Queries("param2", "{param2:[0-9,]+}", "param1", "{param1:[0-9,]+}").
    Handler(negroni.New(
        a.contentTypeJSON,
        negroni.HandlerFunc(a.listSecond),
    ))

I have already looked at these but they dont answer the question link1 link2

UPDATE

Short answer: Order matters

Tip: Don't be a fool and use correct handler function

Routers normally match things in the order they are added, so ordering matters. That means you need to reverse the order of all 3 routes in your code. The most specialized match must come first for things to function properly. This is just an assumption from how routing usually works, as I don't have experience with gorilla mux, but I would be surprised if it didn't follow the same idiom. — super

SamuelTJackson SamuelTJackson · Accepted Answer · 2020-07-21T12:20:13

You have to change the order because the order matters. The first match gets selected

a.Router.
    Methods(http.MethodGet).
    Path("/service/{locale}").
    Queries("param2", "{param2:[0-9,]+}", "param1", "{param1:[0-9,]+}").
    Handler(negroni.New(
        a.contentTypeJSON,
        negroni.HandlerFunc(a.listSecond),
    ))

a.Router.
    Methods(http.MethodGet).
    Path("/service/{locale}").
    Queries("param1", "{param1:[0-9,]+}").
    Handler(negroni.New(
        a.contentTypeJSON,
        negroni.HandlerFunc(a.listFirst),
    ))

a.Router.
    Methods(http.MethodGet).
    Path("/service/{locale}").
    Handler(negroni.New(
        a.contentTypeJSON,
        negroni.HandlerFunc(a.listAll),
    ))

Gorilla Mux same endpoint multiple query params

2 Answers