xref: /aosp_15_r20/external/pigweed/pw_rpc/nanopb/public/pw_rpc/nanopb/client_testing.h (revision 61c4878ac05f98d0ceed94b57d316916de578985)
1 // Copyright 2021 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 //     https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14 #pragma once
15 
16 #include <cstddef>
17 #include <cstdint>
18 #include <optional>
19 
20 #include "pw_bytes/span.h"
21 #include "pw_rpc/client.h"
22 #include "pw_rpc/internal/method_info.h"
23 #include "pw_rpc/nanopb/fake_channel_output.h"
24 #include "pw_rpc/raw/client_testing.h"
25 
26 namespace pw::rpc {
27 
28 // TODO: b/234878467 - Document the client testing APIs.
29 
30 // Sends packets to an RPC client as if it were a pw_rpc server. Accepts
31 // payloads as Nanopb structs.
32 class NanopbFakeServer : public FakeServer {
33  private:
34   template <auto kMethod>
35   using Response = typename internal::MethodInfo<kMethod>::Response;
36 
37  public:
38   using FakeServer::FakeServer;
39 
40   // Sends a response packet for a server or bidirectional streaming RPC to the
41   // client.
42   template <auto kMethod>
43   void SendResponse(Status status,
44                     std::optional<uint32_t> call_id = std::nullopt) const {
45     FakeServer::SendResponse<kMethod>(status, call_id);
46   }
47 
48   // Sends a response packet for a unary or client streaming streaming RPC to
49   // the client.
50   template <auto kMethod,
51             size_t kEncodeBufferSizeBytes = 2 * sizeof(Response<kMethod>)>
52   void SendResponse(const Response<kMethod>& payload,
53                     Status status,
54                     std::optional<uint32_t> call_id = std::nullopt) const {
55     std::byte buffer[kEncodeBufferSizeBytes] = {};
56     FakeServer::SendResponse<kMethod>(
57         EncodeResponse<kMethod>(&payload, buffer), status, call_id);
58   }
59 
60   // Sends a stream packet for a server or bidirectional streaming RPC to the
61   // client.
62   template <auto kMethod,
63             size_t kEncodeBufferSizeBytes = 2 * sizeof(Response<kMethod>)>
64   void SendServerStream(const Response<kMethod>& payload,
65                         std::optional<uint32_t> call_id = std::nullopt) const {
66     std::byte buffer[kEncodeBufferSizeBytes] = {};
67     FakeServer::SendServerStream<kMethod>(
68         EncodeResponse<kMethod>(&payload, buffer), call_id);
69   }
70 
71  private:
72   template <auto kMethod>
EncodeResponse(const void * payload,ByteSpan buffer)73   static ConstByteSpan EncodeResponse(const void* payload, ByteSpan buffer) {
74     const StatusWithSize result =
75         internal::MethodInfo<kMethod>::serde().response().Encode(payload,
76                                                                  buffer);
77     PW_ASSERT(result.ok());
78     return span(buffer).first(result.size());
79   }
80 };
81 
82 // Instantiates a NanopbFakeServer, Client, Channel, and NanopbFakeChannelOutput
83 // for testing RPC client calls. These components may be used individually, but
84 // are instantiated together for convenience.
85 template <size_t kMaxPackets = 10,
86           size_t kPacketEncodeBufferSizeBytes = 128,
87           size_t kPayloadsBufferSizeBytes = 256>
88 class NanopbClientTestContext {
89  public:
NanopbClientTestContext()90   constexpr NanopbClientTestContext()
91       : channel_(Channel::Create<kDefaultChannelId>(&channel_output_)),
92         client_(span(&channel_, 1)),
93         packet_buffer_{},
94         fake_server_(
95             channel_output_, client_, kDefaultChannelId, packet_buffer_) {}
96 
channel()97   const Channel& channel() const { return channel_; }
channel()98   Channel& channel() { return channel_; }
99 
server()100   const NanopbFakeServer& server() const { return fake_server_; }
server()101   NanopbFakeServer& server() { return fake_server_; }
102 
client()103   const Client& client() const { return client_; }
client()104   Client& client() { return client_; }
105 
output()106   const auto& output() const { return channel_output_; }
output()107   auto& output() { return channel_output_; }
108 
109  private:
110   static constexpr uint32_t kDefaultChannelId = 1;
111 
112   NanopbFakeChannelOutput<kMaxPackets, kPayloadsBufferSizeBytes>
113       channel_output_;
114   Channel channel_;
115   Client client_;
116   std::byte packet_buffer_[kPacketEncodeBufferSizeBytes];
117   NanopbFakeServer fake_server_;
118 };
119 
120 }  // namespace pw::rpc
121