Add Body.to_string for converting entire bodies to strings

Author: anuragsoni

CHANGES.md

@@ -1,6 +1,7 @@
 # 0.10.1
 
 * Accept a `(string * string) list` as http headers.
+* Add a `Body.to_string` for reading entire bodies as string.
 
 # 0.10.0
 

README.md

@@ -99,26 +99,6 @@ let httpbin_address =
 
 If the incoming response's body fits entirely in the client's buffer Shuttle_http will represent the body as a fixed sized string, otherwise the body is read as an asynchronous stream so the response can be processed without having to wait for the entire body to arrive over the write.
 
-We'll write a utility function that will convert a streaming response body to a string:
-
-```ocaml
-let response_body_to_string response =
-  let stream_to_string stream =
-    let buffer = Buffer.create 128 in
-    let%map () =
-      Body.Stream.iter stream ~f:(fun chunk ->
-        Buffer.add_string buffer chunk;
-        Deferred.unit)
-    in
-    Buffer.contents buffer
-  in
-  match Response.body response with
-  | Body.Empty -> return ""
-  | Body.Fixed str -> return str
-  | Body.Stream stream -> stream_to_string stream
-;;
-```
-
 Shuttle_http offers a few different flavors of HTTP clients. The first one we'll see is a OneShot client. OneShot clients open a new TCP
 connection, send a HTTP Request, wait to receive a Response and then shut-down the TCP connection once the entire response has been consumed.
 
@@ -133,7 +113,7 @@ let one_shot_client () =
       (Request.create `GET "/get")
   in
   printf "Response status: %d\n" (Response.status response |> Status.to_int);
-  let%map body = response_body_to_string response in
+  let%map body = Body.to_string (Response.body response) in
   print_endline body
 ;;
 ```

http/src/body.ml

@@ -75,3 +75,9 @@ let to_stream = function
   | Fixed x -> Stream.of_pipe (`Fixed (String.length x)) (Pipe.singleton x)
   | Stream x -> x
 ;;
+
+let to_string = function
+  | Empty -> return ""
+  | Fixed s -> return s
+  | Stream x -> Stream.to_string x
+;;

http/src/body.mli

@@ -71,3 +71,7 @@ val stream : Stream.t -> t
 
 (** [to_stream] converts a HTTP body to a stream. *)
 val to_stream : t -> Stream.t
+
+(** [to_string] returns a deferred that will be fulfilled with the entire body converted
+    to a string. *)
+val to_string : t -> string Deferred.t

http/test/test_http.ml

@@ -199,17 +199,6 @@ let%expect_test "Keep-alives in clients" =
            (Client.Address.of_host_and_port
               (Host_and_port.create ~host:"localhost" ~port)))
     in
-    let body_to_string response =
-      let buf = Buffer.create 32 in
-      let%map () =
-        Body.Stream.iter
-          (Body.to_stream (Response.body response))
-          ~f:(fun v ->
-            Buffer.add_string buf v;
-            Deferred.unit)
-      in
-      Buffer.contents buf
-    in
     Monitor.protect
       ~finally:(fun () -> Client.close client)
       (fun () ->
@@ -220,7 +209,7 @@ let%expect_test "Keep-alives in clients" =
             ; headers = (Response.headers response : (string * string) list)
             ; reason_phrase = (Response.reason_phrase response : string)
             }];
-        let%bind body = body_to_string response in
+        let%bind body = Body.to_string (Response.body response) in
         printf "\nBody: %S" body;
         [%expect
           {|
@@ -238,7 +227,7 @@ let%expect_test "Keep-alives in clients" =
             ; headers = (Response.headers response : (string * string) list)
             ; reason_phrase = (Response.reason_phrase response : string)
             }];
-        let%map body = body_to_string response in
+        let%map body = Body.to_string (Response.body response) in
         printf "\nBody: %S" body;
         [%expect
           {|
@@ -270,17 +259,6 @@ let%expect_test "No requests can be sent if a client is closed" =
            (Client.Address.of_host_and_port
               (Host_and_port.create ~host:"localhost" ~port)))
     in
-    let body_to_string response =
-      let buf = Buffer.create 32 in
-      let%map () =
-        Body.Stream.iter
-          (Body.to_stream (Response.body response))
-          ~f:(fun v ->
-            Buffer.add_string buf v;
-            Deferred.unit)
-      in
-      Buffer.contents buf
-    in
     Monitor.protect
       ~finally:(fun () -> Client.close client)
       (fun () ->
@@ -291,7 +269,7 @@ let%expect_test "No requests can be sent if a client is closed" =
             ; headers = (Response.headers response : (string * string) list)
             ; reason_phrase = (Response.reason_phrase response : string)
             }];
-        let%bind body = body_to_string response in
+        let%bind body = Body.to_string (Response.body response) in
         printf "\nBody: %S" body;
         [%expect
           {|
@@ -319,17 +297,6 @@ let%expect_test "Clients are automatically closed if Connection:close header is
            (Client.Address.of_host_and_port
               (Host_and_port.create ~host:"localhost" ~port)))
     in
-    let body_to_string response =
-      let buf = Buffer.create 32 in
-      let%map () =
-        Body.Stream.iter
-          (Body.to_stream (Response.body response))
-          ~f:(fun v ->
-            Buffer.add_string buf v;
-            Deferred.unit)
-      in
-      Buffer.contents buf
-    in
     Monitor.protect
       ~finally:(fun () -> Client.close client)
       (fun () ->
@@ -342,7 +309,7 @@ let%expect_test "Clients are automatically closed if Connection:close header is
             ; headers = (Response.headers response : (string * string) list)
             ; reason_phrase = (Response.reason_phrase response : string)
             }];
-        let%bind body = body_to_string response in
+        let%bind body = Body.to_string (Response.body response) in
         printf "\nBody: %S" body;
         [%expect
           {|
@@ -369,17 +336,6 @@ let%expect_test "Clients are automatically closed if Connection:close header is
            (Client.Address.of_host_and_port
               (Host_and_port.create ~host:"localhost" ~port)))
     in
-    let body_to_string response =
-      let buf = Buffer.create 32 in
-      let%map () =
-        Body.Stream.iter
-          (Body.to_stream (Response.body response))
-          ~f:(fun v ->
-            Buffer.add_string buf v;
-            Deferred.unit)
-      in
-      Buffer.contents buf
-    in
     Monitor.protect
       ~finally:(fun () -> Client.close client)
       (fun () ->
@@ -390,7 +346,7 @@ let%expect_test "Clients are automatically closed if Connection:close header is
             ; headers = (Response.headers response : (string * string) list)
             ; reason_phrase = (Response.reason_phrase response : string)
             }];
-        let%bind body = body_to_string response in
+        let%bind body = Body.to_string (Response.body response) in
         printf "\nBody: %S" body;
         [%expect
           {|
@@ -420,17 +376,6 @@ let%expect_test "Persistent clients will re-connect if connection is closed" =
             (Client.Address.of_host_and_port
                (Host_and_port.create ~host:"localhost" ~port)))
     in
-    let body_to_string response =
-      let buf = Buffer.create 32 in
-      let%map () =
-        Body.Stream.iter
-          (Body.to_stream (Response.body response))
-          ~f:(fun v ->
-            Buffer.add_string buf v;
-            Deferred.unit)
-      in
-      Buffer.contents buf
-    in
     Monitor.protect
       ~finally:(fun () -> Client.Persistent.close client)
       (fun () ->
@@ -443,7 +388,7 @@ let%expect_test "Persistent clients will re-connect if connection is closed" =
             ; headers = (Response.headers response : (string * string) list)
             ; reason_phrase = (Response.reason_phrase response : string)
             }];
-        let%bind body = body_to_string response in
+        let%bind body = Body.to_string (Response.body response) in
         printf "\nBody: %S" body;
         [%expect
           {|
@@ -464,7 +409,7 @@ let%expect_test "Persistent clients will re-connect if connection is closed" =
             ; headers = (Response.headers response : (string * string) list)
             ; reason_phrase = (Response.reason_phrase response : string)
             }];
-        let%map body = body_to_string response in
+        let%map body = Body.to_string (Response.body response) in
         printf "\nBody: %S" body;
         [%expect
           {|