Refactor + fix content-length issue

This way need to generate a bit less code.

Also include the  Content-Length header always in POST requests made by the
client. This fixes an issue when we are serializing a message with no fields and
we have empty body. HttpClient does not include the Content-Length header for
us, so we'll just include it every time to make our requests work in all cases.

2 files changed, 20 insertions, 12 deletions

diff --git a/nimtwirp/generator.nim b/nimtwirp/generator.nim
index 5ea9137..167ad17 100644
--- a/nimtwirp/generator.nim
+++ b/nimtwirp/generator.nim
@@ -88,9 +88,7 @@ proc genClient(service: Service, prefix: string): string =
 
 
 type
-    {service.name}Client* = ref object
-        client*: HttpClient
-        address*: string
+    {service.name}Client* = ref object of nimtwirp.Client
 
 proc new{service.name}Client*(address: string): {service.name}Client =
     new(result)
@@ -104,15 +102,8 @@ proc new{service.name}Client*(address: string): {service.name}Client =
         result &= &"""
 proc {meth.name}*(client: {service.name}Client, req: {meth.inputType}): {meth.outputType} =
     let body = serialize(req)
-    let resp = client.client.request(client.address & {service.name}Prefix & "{meth.name}", httpMethod=HttpPost, body=body)
-    let httpStatus = code(resp)
-    if httpStatus != Http200:
-        if contentType(resp) != "application/json":
-            raise newTwirpError(TwirpInternal, "Invalid Content-Type in response")
-        let errorInfo = parseJson(resp.body)
-        raise twirpErrorFromJson(errorInfo)
-    else:
-        result = new{meth.outputType}(resp.body)
+    let resp = request(client, {service.name}Prefix, "{meth.name}", body)
+    result = new{meth.outputType}(resp.body)
 
 """
 
diff --git a/nimtwirp/nimtwirp.nim b/nimtwirp/nimtwirp.nim
index 32921bc..7c30980 100644
--- a/nimtwirp/nimtwirp.nim
+++ b/nimtwirp/nimtwirp.nim
@@ -1,5 +1,6 @@
 import asyncdispatch
 import asynchttpserver
+import httpclient
 import json
 import macros
 import strformat
@@ -18,6 +19,10 @@ type
 
     ServeHandlerProc = proc (request: asynchttpserver.Request): Future[nimtwirp.Response] {.gcsafe, closure.}
 
+    Client* = ref object of RootObj
+        client*: HttpClient
+        address*: string
+
 proc respond*(req: asynchttpserver.Request, resp: nimtwirp.Response): Future[void] =
     req.respond(resp.code, resp.body, resp.headers)
 
@@ -99,3 +104,15 @@ proc handler(request: asynchttpserver.Request): Future[nimtwirp.Response] {{.asy
     result = newStmtList()
     add(result, handlerProc)
     add(result, parseStmt(&"nimtwirp.serve(handler, {settings.symbol})"))
+
+proc request*(client: Client, prefix: string, meth: string, body: string): httpclient.Response =
+    let address = client.address & prefix & meth
+    let headers = newHttpHeaders({"Content-Length": $len(body)})
+    result = request(client.client, address, httpMethod=HttpPost, body=body,
+        headers=headers)
+    let httpStatus = code(result)
+    if httpStatus != Http200:
+        if contentType(result) != "application/json":
+            raise newTwirpError(TwirpInternal, "Invalid Content-Type in response")
+        let errorInfo = parseJson(result.body)
+        raise twirpErrorFromJson(errorInfo)