Add some convenients functions.

mehari-eio/mehari_eio.ml

@@ -26,16 +26,20 @@ type middleware = handler -> handler
 type route = Router.route
 type rate_limiter = RateLimiter.t
 
-let make_rate_limit = RateLimiter.make
 let set_log_lvl = Logger.set_level
 let logger = Logger.logger
 let debug = Logger.debug
 let info = Logger.info
 let warning = Logger.warning
 let error = Logger.error
+let no_middleware = Router.no_middleware
+let pipeline = Router.pipeline
 let router = Router.router
 let route = Router.route
 let scope = Router.scope
-let virtual_hosts = Router.virtual_hosts
+let no_route = Router.no_route
+
 let response_document = File.response_document
+let virtual_hosts = Router.virtual_hosts
+let make_rate_limit = RateLimiter.make
 let run = Server.run

mehari-mirage/mehari_mirage.ml

@@ -59,16 +59,21 @@ module Make
     Mehari.response_gemtext ?charset ?lang g |> IO.return
 
   let respond_raw g = Mehari.response_raw g |> IO.return
-  let make_rate_limit = RateLimiter.make
   let set_log_lvl = Logger.set_level
   let logger = Logger.logger
   let debug = Logger.debug
   let info = Logger.info
   let warning = Logger.warning
   let error = Logger.error
+
+  let no_middleware = Router.no_middleware
+  let pipeline = Router.pipeline
+
   let router = Router.router
   let route = Router.route
   let scope = Router.scope
+  let no_route = Router.no_route
   let virtual_hosts = Router.virtual_hosts
+  let make_rate_limit = RateLimiter.make
   let run = Server.run
 end

mehari/mehari.ml

@@ -47,6 +47,8 @@ module type NET = sig
   type handler = addr Request.t -> Response.t IO.t
   type middleware = handler -> handler
 
+  val no_middleware : middleware
+  val pipeline : middleware list -> middleware
   val router : route list -> handler
 
   val route :
@@ -60,6 +62,8 @@ module type NET = sig
   val scope :
     ?rate_limit:rate_limiter -> ?mw:middleware -> string -> route list -> route
 
+  val no_route : route
+
   val make_rate_limit :
     ?period:int -> int -> [ `Second | `Minute | `Hour | `Day ] -> rate_limiter
 

mehari/mehari.mli

@@ -59,7 +59,6 @@ assert ([ quote "hello\nworld" ] = [ quote "hello"; text "world" ])
   val heading : [ `H1 | `H2 | `H3 ] -> string -> line
   val list_item : string -> line
   val quote : string -> line
-
   val pp : Format.formatter -> t -> unit
 end
 
@@ -264,7 +263,26 @@ module type NET = sig
 
   type middleware = handler -> handler
   (** Middlewares take a {!type:handler}, and run some code before or
-      after — producing a “bigger” {!type:handler}. *)
+      after — producing a “bigger” {!type:handler}. See
+      {!section-middleware}. *)
+
+  (** {1:middleware} Middleware *)
+
+  val no_middleware : middleware
+  (** Does nothing but call its inner handler. Useful for disabling middleware
+      conditionally during application startup:
+
+      {@ocaml[
+if development then
+  my_middleware
+else
+  Mehari.no_middleware
+]} *)
+
+  val pipeline : middleware list -> middleware
+  (** Combines a list of middlewares into one, such that these two lines are
+      equivalent: [Mehari.pipeline [ mw1 ; mw2 ] @@ handler]
+      [ mw1 @@ mw2 @@ handler]. *)
 
   (** {1:routing Routing} *)
 
@@ -290,6 +308,11 @@ module type NET = sig
   (** [scope ~rate_limit ~mw prefix routes] groups [routes] under the path
       [prefix], [rate_limit] and [mw]. *)
 
+  val no_route : route
+  (** A dummy value of type {!type:route} that is completely ignored by the
+      router. Useful for disabling routes conditionally during application
+      start. *)
+
   (** {1:rate_limit Rate limit} *)
 
   val make_rate_limit :
@@ -433,6 +456,8 @@ module Private : sig
       type handler = addr Handler.Make(IO).t
       type middleware = handler -> handler
 
+      val no_middleware : middleware
+      val pipeline : middleware list -> middleware
       val router : route list -> handler
 
       val route :
@@ -450,6 +475,7 @@ module Private : sig
         route list ->
         route
 
+      val no_route : route
       val virtual_hosts : (string * handler) list -> handler
     end
 

mehari/router_impl.ml

@@ -7,6 +7,8 @@ module type S = sig
   type handler = addr Handler.Make(IO).t
   type middleware = handler -> handler
 
+  val no_middleware : middleware
+  val pipeline : middleware list -> middleware
   val router : route list -> handler
 
   val route :
@@ -20,6 +22,7 @@ module type S = sig
   val scope :
     ?rate_limit:rate_limiter -> ?mw:middleware -> string -> route list -> route
 
+  val no_route : route
   val virtual_hosts : (string * handler) list -> handler
 end
 
@@ -42,6 +45,8 @@ module Make (RateLimiter : Rate_limiter_impl.S) (Logger : Logger_impl.S) :
     rate_limit : RateLimiter.t option;
   }
 
+  let no_route = []
+
   let route ?rate_limit ?(mw = Fun.id) ?(typ = `Raw) r handler =
     [ { route = (typ, r); handler = mw handler; rate_limit } ]
 
@@ -98,6 +103,11 @@ module Make (RateLimiter : Rate_limiter_impl.S) (Logger : Logger_impl.S) :
                 handler req
             | Some resp -> resp))
 
+  let scope ?rate_limit ?(mw = Fun.id) prefix routes =
+    List.concat routes
+    |> List.map (fun { route = typ, r; handler; _ } ->
+           { route = (typ, prefix ^ r); handler = mw handler; rate_limit })
+
   let virtual_hosts domains_handler req =
     let req_host =
       Request.uri req |> Uri.host
@@ -107,8 +117,8 @@ module Make (RateLimiter : Rate_limiter_impl.S) (Logger : Logger_impl.S) :
     | None -> assert false (* Guaranteed by [Protocol.make_request]. *)
     | Some (_, handler) -> handler req
 
-  let scope ?rate_limit ?(mw = Fun.id) prefix routes =
-    List.concat routes
-    |> List.map (fun { route = typ, r; handler; _ } ->
-           { route = (typ, prefix ^ r); handler = mw handler; rate_limit })
+  let no_middleware h req = h req
+
+  let rec pipeline mws handler =
+    match mws with [] -> handler | m :: ms -> m (pipeline ms handler)
 end