From 8d8e42bd8d402e4292d07ddf2249d220a41aebe6 Mon Sep 17 00:00:00 2001
From: Rishab Jaggi <rishab@brex.com>
Date: Fri, 10 Sep 2021 15:19:41 -0400
Subject: [PATCH] Add details to grpc error status struct

---
 lib/grpc/error.ex                     | 22 +++++++++++++++-------
 test/grpc/integration/codec_test.exs  |  3 ++-
 test/grpc/integration/server_test.exs | 13 +++++++++----
 test/grpc/integration/stub_test.exs   |  3 ++-
 4 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/lib/grpc/error.ex b/lib/grpc/error.ex
index c6aff4dc..bf5cb7f5 100644
--- a/lib/grpc/error.ex
+++ b/lib/grpc/error.ex
@@ -5,17 +5,18 @@ defmodule GRPC.RPCError do
       # server side
       raise GRPC.RPCError, status: :unknown # preferred
       raise GRPC.RPCError, status: GRPC.Status.unknown, message: "error message"
+      raise GRPC.RPCError, status: GRPC.Status.unknown, details: [Google.Rpc.LocalizedMessage.new!(locale: “en-US”, message: “User friendly string”)]
 
       # client side
       {:error, error} = Your.Stub.unary_call(channel, request)
   """
 
-  defexception [:status, :message]
-  @type t :: %__MODULE__{status: GRPC.Status.t(), message: String.t()}
+  defexception [:status, :message, :details]
+  @type t :: %__MODULE__{status: GRPC.Status.t(), message: String.t(), details: [any()]}
 
   alias GRPC.Status
 
-  @spec exception(Status.t(), String.t()) :: t
+  @spec exception(Status.t(), String.t(), [any()]) :: t
   def new(status) when is_atom(status) do
     exception(status: status)
   end
@@ -47,12 +48,19 @@ defmodule GRPC.RPCError do
     parse_args(t, acc)
   end
 
-  def exception(status, message) when is_atom(status) do
-    %GRPC.RPCError{status: apply(GRPC.Status, status, []), message: message}
+  defp parse_args([{:details, details} | t], acc) do
+    acc = %{acc | details: details}
+    parse_args(t, acc)
+  end
+
+  def exception(status, message, details \\ [])
+
+  def exception(status, message, details) when is_atom(status) do
+    %GRPC.RPCError{status: apply(GRPC.Status, status, []), message: message, details: details}
   end
 
-  def exception(status, message) when is_integer(status) do
-    %GRPC.RPCError{status: status, message: message}
+  def exception(status, message, details) when is_integer(status) do
+    %GRPC.RPCError{status: status, message: message, details: details}
   end
 
   defp status_message(1), do: "The operation was cancelled (typically by the caller)"
diff --git a/test/grpc/integration/codec_test.exs b/test/grpc/integration/codec_test.exs
index ef28b96a..65d35ca8 100644
--- a/test/grpc/integration/codec_test.exs
+++ b/test/grpc/integration/codec_test.exs
@@ -49,7 +49,8 @@ defmodule GRPC.Integration.CodecTest do
 
       assert %GRPC.RPCError{
                status: GRPC.Status.unimplemented(),
-               message: "No codec registered for content-type application/grpc+not-registered"
+               message: "No codec registered for content-type application/grpc+not-registered",
+               details: []
              } == reply
     end)
   end
diff --git a/test/grpc/integration/server_test.exs b/test/grpc/integration/server_test.exs
index 3960bf10..a1d6e61d 100644
--- a/test/grpc/integration/server_test.exs
+++ b/test/grpc/integration/server_test.exs
@@ -109,7 +109,8 @@ defmodule GRPC.Integration.ServerTest do
 
       assert %GRPC.RPCError{
                status: GRPC.Status.unauthenticated(),
-               message: "Please authenticate"
+               message: "Please authenticate",
+               details: []
              } == reply
     end)
   end
@@ -120,7 +121,11 @@ defmodule GRPC.Integration.ServerTest do
       req = Helloworld.HelloRequest.new(name: "unknown error")
 
       assert {:error,
-              %GRPC.RPCError{message: "Internal Server Error", status: GRPC.Status.unknown()}} ==
+              %GRPC.RPCError{
+                message: "Internal Server Error",
+                status: GRPC.Status.unknown(),
+                details: []
+              }} ==
                channel |> Helloworld.Greeter.Stub.say_hello(req)
     end)
   end
@@ -129,7 +134,7 @@ defmodule GRPC.Integration.ServerTest do
     run_server([FeatureErrorServer], fn port ->
       {:ok, channel} = GRPC.Stub.connect("localhost:#{port}")
       rect = Routeguide.Rectangle.new()
-      error = %GRPC.RPCError{message: "Please authenticate", status: 16}
+      error = %GRPC.RPCError{message: "Please authenticate", status: 16, details: []}
       assert {:error, ^error} = channel |> Routeguide.RouteGuide.Stub.list_features(rect)
     end)
   end
@@ -148,7 +153,7 @@ defmodule GRPC.Integration.ServerTest do
     run_server([TimeoutServer], fn port ->
       {:ok, channel} = GRPC.Stub.connect("localhost:#{port}")
       rect = Routeguide.Rectangle.new()
-      error = %GRPC.RPCError{message: "Deadline expired", status: 4}
+      error = %GRPC.RPCError{message: "Deadline expired", status: 4, details: []}
 
       assert {:error, ^error} =
                channel |> Routeguide.RouteGuide.Stub.list_features(rect, timeout: 500)
diff --git a/test/grpc/integration/stub_test.exs b/test/grpc/integration/stub_test.exs
index 7a256429..c9f3eb78 100644
--- a/test/grpc/integration/stub_test.exs
+++ b/test/grpc/integration/stub_test.exs
@@ -74,7 +74,8 @@ defmodule GRPC.Integration.StubTest do
       assert {:error,
               %GRPC.RPCError{
                 message: "Deadline expired",
-                status: GRPC.Status.deadline_exceeded()
+                status: GRPC.Status.deadline_exceeded(),
+                details: []
               }} == channel |> Helloworld.Greeter.Stub.say_hello(req, timeout: 500)
     end)
   end