Provide bindings for NextJs req and res types

Author: DZakh

src/RestNextJs.res

@@ -16,10 +16,43 @@ module Exn = {
 @inline
 let panic = message => Exn.raiseError(Exn.makeError(`[rescript-rest] ${message}`))
 
-type options<'input, 'req, 'res> = {
+type req = private {
+  cookies: Js.Dict.t<string>,
+  method: Rest.method,
+  url: string,
+  port: int,
+  body: Js.Json.t,
+  query: Js.Json.t,
+  headers: Js.Dict.t<string>,
+  rawHeaders: array<string>,
+  rawTrailers: array<string>,
+  aborted: bool,
+  complete: bool,
+  statusCode: Rest.Response.numiricStatus,
+  statusMessage: string,
+  trailers: Js.Dict.t<string>,
+}
+// @send
+// external destroy: (req, ~error: option<Js.Exn.t>=?) => bool = "destroy"
+
+type reply
+type rec res = private {
+  statusCode: Rest.Response.numiricStatus,
+  statusMessage: string,
+  getHeader: string => option<string>,
+  setHeader: (string, string) => unit,
+  status: int => res,
+  end: unit => reply,
+  json: Js.Json.t => reply,
+  // The type is not 100% correct.
+  // It asccepts a string, object or a Buffer
+  send: Js.Json.t => reply,
+}
+
+type options<'input> = {
   input: 'input,
-  req: 'req,
-  res: 'res,
+  req: req,
+  res: res,
 }
 
 let handler = (route, implementation) => {
@@ -41,40 +74,38 @@ let handler = (route, implementation) => {
     )
   }
 
-  async (genericReq, genericRes) => {
-    let req = genericReq->Obj.magic
-    let res = genericRes->Obj.magic
-
-    if req["method"] !== definition.method {
-      res["status"](404)["end"]()
-    }
-    switch req->S.parseOrThrow(inputSchema) {
-    | input =>
-      try {
-        let implementationResult = await implementation({
-          req: genericReq,
-          res: genericRes,
-          input,
-        })
-        let data: {..} = implementationResult->S.reverseConvertOrThrow(responseSchema)->Obj.magic
-        let headers: option<dict<string>> = data["headers"]
-        switch headers {
-        | Some(headers) =>
-          headers
-          ->Js.Dict.keys
-          ->Js.Array2.forEach(key => {
-            res["setHeader"](key, headers->Js.Dict.unsafeGet(key))
+  async (req, res) => {
+    if req.method !== definition.method {
+      res.status(404).end()
+    } else {
+      switch req->S.parseOrThrow(inputSchema) {
+      | input =>
+        try {
+          let implementationResult = await implementation({
+            req,
+            res,
+            input,
           })
-        | None => ()
+          let data: {..} = implementationResult->S.reverseConvertOrThrow(responseSchema)->Obj.magic
+          let headers: option<dict<string>> = data["headers"]
+          switch headers {
+          | Some(headers) =>
+            headers
+            ->Js.Dict.keys
+            ->Js.Array2.forEach(key => {
+              res.setHeader(key, headers->Js.Dict.unsafeGet(key))
+            })
+          | None => ()
+          }
+          res.status(%raw(`data.status || 200`)).json(data["data"])
+        } catch {
+        | S.Raised(error) =>
+          Js.Exn.raiseError(
+            `Unexpected error in the ${definition.path} route: ${error->S.Error.message}`,
+          )
         }
-        res["status"](%raw(`data.status || 200`))["json"](data["data"])
-      } catch {
-      | S.Raised(error) =>
-        Js.Exn.raiseError(
-          `Unexpected error in the ${definition.path} route: ${error->S.Error.message}`,
-        )
+      | exception S.Raised(error) => res.status(400).send(error->S.Error.message->Js.Json.string)
       }
-    | exception S.Raised(error) => res["status"](400)["send"](error->S.Error.message)
     }
   }
 }

src/RestNextJs.res.js

@@ -1,12 +1,43 @@
 @@uncurried
 
-type options<'input, 'req, 'res> = {
+type req = private {
+  cookies: Js.Dict.t<string>,
+  method: Rest.method,
+  url: string,
+  port: int,
+  body: Js.Json.t,
+  query: Js.Json.t,
+  headers: Js.Dict.t<string>,
+  rawHeaders: array<string>,
+  rawTrailers: array<string>,
+  aborted: bool,
+  complete: bool,
+  statusCode: Rest.Response.numiricStatus,
+  statusMessage: string,
+  trailers: Js.Dict.t<string>,
+}
+
+type reply
+type rec res = private {
+  statusCode: Rest.Response.numiricStatus,
+  statusMessage: string,
+  getHeader: string => option<string>,
+  setHeader: (string, string) => unit,
+  status: int => res,
+  end: unit => reply,
+  json: Js.Json.t => reply,
+  // The type is not 100% correct.
+  // It asccepts a string, object or a Buffer
+  send: Js.Json.t => reply,
+}
+
+type options<'input> = {
   input: 'input,
-  req: 'req,
-  res: 'res,
+  req: req,
+  res: res,
 }
 
 let handler: (
   Rest.route<'input, 'response>,
-  options<'input, 'req, 'res> => promise<'response>,
-) => ('req, 'res) => promise<'reply>
+  options<'input> => promise<'response>,
+) => (req, res) => promise<reply>