http-client: content-type override, split header values

Add a "response-content-type-override" field to the resolve step
to override body parsing behavior.

Send each reponse header as a seperate message rather than
concatenated by the Nim HTTP client library.

README.md

@@ -302,7 +302,7 @@ $client-resolver ? <accepted ?client> $client [
 
 # Pass the resolver dataspace to the client.
 ? <service-object <daemon http-client> ?cap> [
-  $cap <resolve <http-client {}> $client-resolver>
+  $cap <resolve <http-client { response-content-type-override: "" }> $client-resolver>
 ]
 
 <require-service <daemon http-client>>

config.prs

@@ -24,7 +24,15 @@ UnixAddress = <unix @path string>.
 
 SocketAddress = TcpAddress / UnixAddress .
 
-HttpClientStep = <http-client { }>.
+HttpClientStep = <http-client @detail HttpClientStepDetail>.
+HttpClientStepDetail = {
+  # Body parsing happens according to a heuristic interpretation
+  # of Content-Type headers.
+  # Set this field as "application/octet-stream" to never parse
+  # response bodies or to "application/json" to parse all response
+  # bodies as JSON.
+  response-content-type-override: string
+} .
 
 HttpDriverStep= <http-driver { }>.
 

sbom.json

@@ -7,7 +7,7 @@
       "bom-ref": "pkg:nim/syndicate_utils",
       "name": "syndicate_utils",
       "description": "Utilites for Syndicated Actors and Synit",
-      "version": "20240621",
+      "version": "20240622",
       "authors": [
         {
           "name": "Emery Hemingway"

src/http_client.nim

@@ -28,7 +28,7 @@ proc url(req: HttpRequest): Uri =
 
 proc toContent(body: Value; contentType: var string): string =
   case contentType
-  of "application/json":
+  of "application/json", "text/javascript":
     var stream = newStringStream()
     writeText(stream, body, textJson)
     return stream.data.move
@@ -52,9 +52,9 @@ proc toContent(body: Value; contentType: var string): string =
     raise newException(ValueError, "unknown content type")
 
 proc spawnHttpClient*(turn: Turn; relay: Cap): Actor {.discardable.} =
-  let pat = Resolve?:{ 0: HttpClientStep.matchType, 1: grab() }
+  let pat = Resolve?:{ 0: HttpClientStep.grabWithin, 1: grab() }
   result = spawnActor(turn, "http-client") do (turn: Turn):
-    during(turn, relay, pat) do (observer: Cap):
+    during(turn, relay, pat) do (detail: HttpClientStepDetail, observer: Cap):
       linkActor(turn, "session") do (turn: Turn):
         let ds = turn.newDataspace()
         discard publish(turn, observer, ResolvedAccepted(responderSession: ds))
@@ -64,7 +64,7 @@ proc spawnHttpClient*(turn: Turn; relay: Cap): Actor {.discardable.} =
           try:
             var
               headers = newHttpHeaders()
-              contentType = ""
+              contentType: string
             for key, val in ctx.req.headers:
               if key == Symbol"content-type" or key == Symbol"Content-Type":
                 contentType = val
@@ -74,20 +74,23 @@ proc spawnHttpClient*(turn: Turn; relay: Cap): Actor {.discardable.} =
                 ctx.req.method.string.toUpper,
                 ctx.req.body.toContent(contentType), headers
               )
-            client.headers["content-type"] = contentType
             var resp = HttpResponse(orKind: HttpResponseKind.status)
             resp.status.code = stdRes.status[0 .. 2].parseInt
             resp.status.message = stdRes.status[3 .. ^1]
             message(turn, peer, resp)
             resp = HttpResponse(orKind: HttpResponseKind.header)
-            for key, val in stdRes.headers:
+            for key, vals in stdRes.headers.table:
-              if key == "Content-Type":
+              for val in vals.items:
+                resp.header.name = key.Symbol
+                resp.header.value = val
+                message(turn, peer, resp)
+            if detail.`response-content-type-override` != "":
+              contentType = detail.`response-content-type-override`
+            else:
+              for val in stdRes.headers.table.getOrDefault("content-type").items:
                 contentType = val
-              resp.header.name = key.Symbol
-              resp.header.value = val
-            message(turn, peer, resp)
             case contentType
-            of "application/json", "text/preserves":
+            of "application/json", "text/preserves", "text/javascript":
               message(turn, peer,
                   initRecord("done", stdRes.bodyStream.readAll.parsePreserves))
             of "application/preserves":

src/schema/config.nim

@@ -39,6 +39,9 @@ type
   XsltArguments* {.preservesRecord: "xslt".} = object
     `field0`*: XsltArgumentsField0
 
+  HttpClientStepDetail* {.preservesDictionary.} = object
+    `response-content-type-override`*: string
+
   JsonSocketTranslatorStepField0* {.preservesDictionary.} = object
     `socket`*: SocketAddress
 
@@ -51,10 +54,8 @@ type
   FileSystemUsageArguments* {.preservesRecord: "file-system-usage".} = object
     `field0`*: FileSystemUsageArgumentsField0
 
-  HttpClientStepField0* {.preservesDictionary.} = object
-  
   HttpClientStep* {.preservesRecord: "http-client".} = object
-    `field0`*: HttpClientStepField0
+    `detail`*: HttpClientStepDetail
 
   HttpDriverStepField0* {.preservesDictionary.} = object
   
@@ -109,6 +110,7 @@ type
 proc `$`*(x: JsonTranslatorArguments | SocketAddress | Base64DecoderArguments |
     SqliteStep |
     XsltArguments |
+    HttpClientStepDetail |
     JsonSocketTranslatorStep |
     FileSystemUsageArguments |
     HttpClientStep |
@@ -127,6 +129,7 @@ proc `$`*(x: JsonTranslatorArguments | SocketAddress | Base64DecoderArguments |
 proc encode*(x: JsonTranslatorArguments | SocketAddress | Base64DecoderArguments |
     SqliteStep |
     XsltArguments |
+    HttpClientStepDetail |
     JsonSocketTranslatorStep |
     FileSystemUsageArguments |
     HttpClientStep |