Make %(ApiResponse) a proc as conversion of wrapped types can have side-effects.

buffoonery.nimble

@@ -1,6 +1,6 @@
 # Package
 
-version       = "0.4.8"
+version       = "0.4.10"
 author        = "Jonathan Bernard"
 description   = "Jonathan's opinionated extensions and auth layer for Jester."
 license       = "MIT"

src/buffoonery/apiutils.nim

@@ -1,5 +1,5 @@
 import std/[json, jsonutils, options, sequtils, strtabs, strutils]
-import mummy, webby
+import mummy, webby, uuids
 
 import std/httpcore except HttpHeaders
 
@@ -31,7 +31,7 @@ func initApiResponse*[T](
     totalItems: totalItems, nextLink: nextLink, prevLink: prevLink)
 
 
-func `%`*(r: ApiResponse): JsonNode =
+proc `%`*(r: ApiResponse): JsonNode =
   result = newJObject()
   if r.details.isSome: result["details"] = %r.details
   if r.data.isSome: result["data"] = %r.data
@@ -90,6 +90,40 @@ func origin*(req: Request): Option[string] =
   else: none[string]()
 
 
+func traceparent*(req: Request): Option[string] =
+  ## Extract the traceparent from the request headers, if present.
+  if req.headers.contains("traceparent"):
+    return some(req.headers["traceparent"])
+  else:
+    return none[string]()
+
+
+proc makeTraceContextHeaders*(req: Request, traceParentId: string): HttpHeaders =
+  var headers = HttpHeaders(@[])
+
+  if req.headers.contains("traceparent"):
+    # If the traceparent header is present, we should update it with our
+    # parent-id.
+    let traceparentParts = req.headers["traceparent"].split("-")
+    if traceparentParts.len != 4:
+      headers["traceparent"] = "00-$#-$#-00" % [
+        replace($genUUID(), "-", ""), # trace-id
+        traceParentId,                # parent-id
+      ]
+
+    else:
+      headers["traceparent"] = "00-$#-$#-$#" % [
+        traceparentParts[1], # trace-id
+        traceParentId,       # parent-id
+        traceparentParts[3], # flags
+      ]
+
+    if req.headers.contains("tracestate"):
+      headers["tracestate"] = req.headers["tracestate"]
+
+  return headers
+
+
 proc respondWithRawJson*(
     req: Request,
     body: JsonNode,