Add client request to telemetry metadata

lib/grpc/stub.ex

@@ -265,7 +265,7 @@ defmodule GRPC.Stub do
         accepted_compressors: accepted_compressors
     }
 
-    GRPC.Telemetry.client_span(stream, fn ->
+    GRPC.Telemetry.client_span(stream, request, fn ->
       do_call(req_stream, stream, request, opts)
     end)
   end

lib/grpc/telemetry.ex

@@ -23,9 +23,7 @@ defmodule GRPC.Telemetry do
   ### Metadata
 
     * `:stream` - the `%GRPC.Server.Stream{}` for the request
-    * `:function_name` - the name of the function called
-    * `:server` - the server module name
-    * `:endpoint` - the endpoint module name
+    * `:request` - the client request
 
   `:exception` events also include some error metadata:
 
@@ -110,8 +108,8 @@ defmodule GRPC.Telemetry do
   def client_rpc_start_name, do: @client_rpc_start_name
 
   @doc false
-  def client_span(stream, span_fn) do
-    start_metadata = %{stream: stream}
+  def client_span(stream, request, span_fn) do
+    start_metadata = %{stream: stream, request: request}
 
     :telemetry.span(@client_rpc, start_metadata, fn ->
       try do

test/grpc/integration/client_interceptor_test.exs

@@ -50,6 +50,14 @@ defmodule GRPC.Integration.ClientInterceptorTest do
   end
 
   test "client sends headers" do
+    client_prefix = GRPC.Telemetry.client_rpc_prefix()
+    stop_client_name = client_prefix ++ [:stop]
+    service_name = Helloworld.Greeter.Service.__meta__(:name)
+
+    attach_events([
+      stop_client_name
+    ])
+
     run_endpoint(HelloEndpoint, fn port ->
       {:ok, channel} =
         GRPC.Stub.connect("localhost:#{port}",
@@ -62,6 +70,15 @@ defmodule GRPC.Integration.ClientInterceptorTest do
       req = Helloworld.HelloRequest.new(name: "Elixir")
       {:ok, reply} = channel |> Helloworld.Greeter.Stub.say_hello(req)
       assert reply.message == "Hello, Elixir one two"
+
+      assert_received {^stop_client_name, _measurements, metadata}
+      assert %{stream: stream, request: ^req} = metadata
+
+      assert %{
+        channel: ^channel,
+        service_name: ^service_name,
+        method_name: "SayHello"
+      } = stream
     end)
   end