commit 54891aeecdbbd29c0ba65ce39bb26942ac5edd20
author Carlos Chinchilla <cachinchilla@google.com> Wed Sep 22 11:26:43 2021 -0700
committer CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Sep 23 15:32:33 2021 +0000
tree 4fa24866965558876ff713477b8141130ca34295
parent f087b00fa2d156d0688b12fc46851c1a23811076

pw_rpc: new FakeChannelOutput testing APIs

- Add an individual count for each packet type.
- Avoid crashing when the channel output is done.
- Add methods to inject an error status useful when testing RPC error
  handling.

No-Docs-Update-Reason: documented in API comments.
Change-Id: I9df303cef3fe6c069fff7350c0dc0e909a326404
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/61906
Pigweed-Auto-Submit: Carlos Chinchilla <cachinchilla@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Reviewed-by: Wyatt Hepler <hepler@google.com>

pw_rpc/fake_channel_output.cc

diff --git a/pw_rpc/fake_channel_output.cc b/pw_rpc/fake_channel_output.cc
index 0fc56dc..7c0a9e5 100644
--- a/pw_rpc/fake_channel_output.cc
+++ b/pw_rpc/fake_channel_output.cc
@@ -22,9 +22,11 @@
 
 void FakeChannelOutput::clear() {
   ClearResponses();
-  total_responses_ = 0;
+  total_response_packets_ = 0;
+  total_stream_packets_ = 0;
   last_status_ = Status::Unknown();
-  done_ = false;
+  send_status_ = OkStatus();
+  return_after_packet_count_ = -1;
 }
 
 Status FakeChannelOutput::SendAndReleaseBuffer(
@@ -36,7 +38,15 @@
     return OkStatus();
   }
 
-  PW_CHECK(!done_);
+  if (return_after_packet_count_ == 0) {
+    return send_status_;
+  }
+  if (return_after_packet_count_ > 0 &&
+      return_after_packet_count_ == static_cast<int>(total_responses())) {
+    // Disable behavior.
+    return_after_packet_count_ = -1;
+    return send_status_;
+  }
 
   Result<Packet> result = Packet::FromBuffer(buffer);
   PW_CHECK_OK(result.status());
@@ -49,12 +59,13 @@
       if (!HasServerStream(method_type_)) {
         ProcessResponse(result.value().payload());
       }
-      done_ = true;
+      ++total_response_packets_;
       break;
     case PacketType::SERVER_ERROR:
       PW_CRASH("Server error: %s", result.value().status().str());
     case PacketType::SERVER_STREAM:
       ProcessResponse(result.value().payload());
+      ++total_stream_packets_;
       break;
     default:
       PW_CRASH("Unhandled PacketType %d",