xref: /aosp_15_r20/external/pigweed/pw_rpc/raw/public/pw_rpc/raw/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 #include <type_traits>
20 
21 #include "pw_bytes/span.h"
22 #include "pw_rpc/client.h"
23 #include "pw_rpc/internal/method_info.h"
24 #include "pw_rpc/internal/packet.h"
25 #include "pw_rpc/method_type.h"
26 #include "pw_rpc/raw/fake_channel_output.h"
27 
28 namespace pw::rpc {
29 
30 // TODO: b/234878467 - Document the client testing APIs.
31 
32 // Sends packets to an RPC client as if it were a pw_rpc server.
33 class FakeServer {
34  public:
FakeServer(internal::test::FakeChannelOutput & output,Client & client,uint32_t channel_id,ByteSpan packet_buffer)35   constexpr FakeServer(internal::test::FakeChannelOutput& output,
36                        Client& client,
37                        uint32_t channel_id,
38                        ByteSpan packet_buffer)
39       : output_(output),
40         client_(client),
41         channel_id_(channel_id),
42         packet_buffer_(packet_buffer) {}
43 
44   // Sends a response packet for a server or bidirectional streaming RPC to the
45   // client.
46   template <auto kMethod,
47             typename = std::enable_if_t<
48                 HasServerStream(internal::MethodInfo<kMethod>::kType)>>
49   void SendResponse(Status status,
50                     std::optional<uint32_t> call_id = std::nullopt) const {
51     SendPacket<kMethod>(
52         internal::pwpb::PacketType::RESPONSE, {}, status, call_id);
53   }
54 
55   // Sends a response packet for a unary or client streaming streaming RPC to
56   // the client.
57   template <auto kMethod,
58             typename = std::enable_if_t<
59                 !HasServerStream(internal::MethodInfo<kMethod>::kType)>>
60   void SendResponse(ConstByteSpan payload,
61                     Status status,
62                     std::optional<uint32_t> call_id = std::nullopt) const {
63     SendPacket<kMethod>(
64         internal::pwpb::PacketType::RESPONSE, payload, status, call_id);
65   }
66 
67   // Sends a stream packet for a server or bidirectional streaming RPC to the
68   // client.
69   template <auto kMethod>
70   void SendServerStream(ConstByteSpan payload,
71                         std::optional<uint32_t> call_id = std::nullopt) const {
72     static_assert(HasServerStream(internal::MethodInfo<kMethod>::kType),
73                   "Only server and bidirectional streaming methods can receive "
74                   "server stream packets");
75     SendPacket<kMethod>(internal::pwpb::PacketType::SERVER_STREAM,
76                         payload,
77                         OkStatus(),
78                         call_id);
79   }
80 
81   // Sends a server error packet to the client.
82   template <auto kMethod>
83   void SendServerError(Status error,
84                        std::optional<uint32_t> call_id = std::nullopt) const {
85     SendPacket<kMethod>(
86         internal::pwpb::PacketType::SERVER_ERROR, {}, error, call_id);
87   }
88 
89  private:
90   template <auto kMethod>
SendPacket(internal::pwpb::PacketType type,ConstByteSpan payload,Status status,std::optional<uint32_t> call_id)91   void SendPacket(internal::pwpb::PacketType type,
92                   ConstByteSpan payload,
93                   Status status,
94                   std::optional<uint32_t> call_id) const {
95     using Info = internal::MethodInfo<kMethod>;
96     CheckProcessPacket(
97         type, Info::kServiceId, Info::kMethodId, call_id, payload, status);
98   }
99 
100   void CheckProcessPacket(internal::pwpb::PacketType type,
101                           uint32_t service_id,
102                           uint32_t method_id,
103                           std::optional<uint32_t> call_id,
104                           ConstByteSpan payload,
105                           Status status) const;
106 
107   Status ProcessPacket(internal::pwpb::PacketType type,
108                        uint32_t service_id,
109                        uint32_t method_id,
110                        std::optional<uint32_t> call_id,
111                        ConstByteSpan payload,
112                        Status status) const;
113 
114   internal::test::FakeChannelOutput& output_;
115   Client& client_;
116   const uint32_t channel_id_;
117   ByteSpan packet_buffer_;  // For encoding packets sent by the server
118 };
119 
120 // Instantiates a FakeServer, Client, Channel, and RawFakeChannelOutput for
121 // testing RPC client calls. These components may be used individually, but are
122 // instantiated together for convenience.
123 template <size_t kMaxPackets = 10,
124           size_t kPacketEncodeBufferSizeBytes = 128,
125           size_t kPayloadsBufferSizeBytes = 256>
126 class RawClientTestContext {
127  public:
128   static constexpr uint32_t kDefaultChannelId = 1;
129 
RawClientTestContext()130   constexpr RawClientTestContext()
131       : channel_(Channel::Create<kDefaultChannelId>(&channel_output_)),
132         client_(span(&channel_, 1)),
133         packet_buffer_{},
134         fake_server_(
135             channel_output_, client_, kDefaultChannelId, packet_buffer_) {}
136 
channel()137   const Channel& channel() const { return channel_; }
channel()138   Channel& channel() { return channel_; }
139 
server()140   const FakeServer& server() const { return fake_server_; }
server()141   FakeServer& server() { return fake_server_; }
142 
client()143   const Client& client() const { return client_; }
client()144   Client& client() { return client_; }
145 
output()146   const auto& output() const { return channel_output_; }
output()147   auto& output() { return channel_output_; }
148 
149  private:
150   RawFakeChannelOutput<kMaxPackets, kPayloadsBufferSizeBytes> channel_output_;
151   Channel channel_;
152   Client client_;
153   std::byte packet_buffer_[kPacketEncodeBufferSizeBytes];
154   FakeServer fake_server_;
155 };
156 
157 }  // namespace pw::rpc
158