Add and use CreateTestFieldTrialsPtr function for convinience and clarity

Though many tests use FieldTrials by value or const reference, some
tests need FieldTrials wrapped into unique_ptr, for example, to pass it
to Environment.

To better support 2nd set of tests, this patch suggest a new simple
wrapper for the common need to create unique_ptr<FieldTrials>.

Bug: webrtc:419453427
Change-Id: Icff3e69d858642f43ad79cea5016a5d850616146
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/397162
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#44991}

api/audio_codecs/opus/audio_decoder_opus_unittest.cc

@@ -17,7 +17,6 @@
 #include "api/audio_codecs/audio_format.h"
 #include "api/environment/environment.h"
 #include "api/environment/environment_factory.h"
-#include "api/field_trials.h"
 #include "test/create_test_field_trials.h"
 #include "test/gmock.h"
 #include "test/gtest.h"
@@ -88,9 +87,8 @@ TEST(AudioDecoderOpusTest, MakeAudioDecoderCannotForceDefaultNumChannels) {
 }
 
 TEST(AudioDecoderOpusTest, MakeAudioDecoderForcesStereo) {
-  const Environment env =
-      CreateEnvironment(std::make_unique<FieldTrials>(CreateTestFieldTrials(
-          "WebRTC-Audio-OpusDecodeStereoByDefault/Enabled/")));
+  const Environment env = CreateEnvironment(CreateTestFieldTrialsPtr(
+      "WebRTC-Audio-OpusDecodeStereoByDefault/Enabled/"));
   auto decoder = AudioDecoderOpus::MakeAudioDecoder(
       env,
       /*config=*/{.num_channels = std::nullopt});
@@ -99,9 +97,8 @@ TEST(AudioDecoderOpusTest, MakeAudioDecoderForcesStereo) {
 }
 
 TEST(AudioDecoderOpusTest, MakeAudioDecoderCannotForceStereo) {
-  const Environment env =
-      CreateEnvironment(std::make_unique<FieldTrials>(CreateTestFieldTrials(
-          "WebRTC-Audio-OpusDecodeStereoByDefault/Enabled/")));
+  const Environment env = CreateEnvironment(CreateTestFieldTrialsPtr(
+      "WebRTC-Audio-OpusDecodeStereoByDefault/Enabled/"));
   auto decoder =
       AudioDecoderOpus::MakeAudioDecoder(env, /*config=*/{.num_channels = 1});
 

api/test/pclf/peer_configurer.cc

@@ -55,8 +55,7 @@ PeerConfigurer::PeerConfigurer(PeerNetworkDependencies& network)
           network.socket_factory())),
       params_(std::make_unique<Params>()),
       configurable_params_(std::make_unique<ConfigurableParams>()) {
-  components_->pcf_dependencies->field_trials =
-      std::make_unique<FieldTrials>(CreateTestFieldTrials());
+  components_->pcf_dependencies->field_trials = CreateTestFieldTrialsPtr();
 }
 
 PeerConfigurer* PeerConfigurer::SetName(absl::string_view name) {

modules/audio_coding/test/TestRedFec.cc

@@ -33,7 +33,6 @@
 #include "api/audio_codecs/opus/audio_decoder_opus.h"
 #include "api/audio_codecs/opus/audio_encoder_opus.h"
 #include "api/environment/environment_factory.h"
-#include "api/field_trials.h"
 #include "api/neteq/default_neteq_factory.h"
 #include "api/neteq/neteq.h"
 #include "common_audio/vad/include/vad.h"
@@ -49,8 +48,7 @@
 namespace webrtc {
 
 TestRedFec::TestRedFec()
-    : env_(CreateEnvironment(
-          std::make_unique<FieldTrials>(CreateTestFieldTrials()))),
+    : env_(CreateEnvironment(CreateTestFieldTrialsPtr())),
       encoder_factory_(CreateAudioEncoderFactory<AudioEncoderG711,
                                                  AudioEncoderG722,
                                                  AudioEncoderL16,

modules/video_coding/codecs/av1/dav1d_decoder_unittest.cc

@@ -18,7 +18,6 @@
 #include "api/array_view.h"
 #include "api/environment/environment.h"
 #include "api/environment/environment_factory.h"
-#include "api/field_trials.h"
 #include "api/video/encoded_image.h"
 #include "api/video/video_frame.h"
 #include "api/video_codecs/video_decoder.h"
@@ -97,9 +96,8 @@ TEST(Dav1dDecoderTest, KeepsDecodedResolutionByDefault) {
 }
 
 TEST(Dav1dDecoderTest, CropsToRenderResolutionWhenCropIsEnabled) {
-  TestAv1Decoder decoder(
-      CreateEnvironment(std::make_unique<FieldTrials>(CreateTestFieldTrials(
-          "WebRTC-Dav1dDecoder-CropToRenderResolution/Enabled/"))));
+  TestAv1Decoder decoder(CreateEnvironment(CreateTestFieldTrialsPtr(
+      "WebRTC-Dav1dDecoder-CropToRenderResolution/Enabled/")));
   decoder.Decode(
       CreateEncodedImage(kAv1FrameWith36x20EncodededAnd32x16RenderResolution));
   EXPECT_EQ(decoder.decoded_frame().width(), 32);
@@ -107,9 +105,8 @@ TEST(Dav1dDecoderTest, CropsToRenderResolutionWhenCropIsEnabled) {
 }
 
 TEST(Dav1dDecoderTest, DoesNotCropToRenderResolutionWhenCropIsDisabled) {
-  TestAv1Decoder decoder(
-      CreateEnvironment(std::make_unique<FieldTrials>(CreateTestFieldTrials(
-          "WebRTC-Dav1dDecoder-CropToRenderResolution/Disabled/"))));
+  TestAv1Decoder decoder(CreateEnvironment(CreateTestFieldTrialsPtr(
+      "WebRTC-Dav1dDecoder-CropToRenderResolution/Disabled/")));
   decoder.Decode(
       CreateEncodedImage(kAv1FrameWith36x20EncodededAnd32x16RenderResolution));
   EXPECT_EQ(decoder.decoded_frame().width(), 36);

modules/video_coding/codecs/test/video_codec_test.cc

@@ -23,7 +23,6 @@
 #include "absl/flags/flag.h"
 #include "api/environment/environment.h"
 #include "api/environment/environment_factory.h"
-#include "api/field_trials.h"
 #include "api/test/metrics/global_metrics_logger_and_exporter.h"
 #include "api/units/data_rate.h"
 #include "api/units/frequency.h"
@@ -575,8 +574,7 @@ INSTANTIATE_TEST_SUITE_P(All,
                          FramerateAdaptationTest::TestParamsToString);
 
 TEST(VideoCodecTest, DISABLED_EncodeDecode) {
-  const Environment env =
-      CreateEnvironment(std::make_unique<FieldTrials>(CreateTestFieldTrials()));
+  const Environment env = CreateEnvironment(CreateTestFieldTrialsPtr());
 
   VideoSourceSettings source_settings{
       .file_path = absl::GetFlag(FLAGS_input_path),

pc/peer_connection_callsetup_perf_tests.cc

@@ -21,7 +21,6 @@
 #include "api/audio_codecs/builtin_audio_decoder_factory.h"
 #include "api/audio_codecs/builtin_audio_encoder_factory.h"
 #include "api/data_channel_interface.h"
-#include "api/field_trials.h"
 #include "api/jsep.h"
 #include "api/make_ref_counted.h"
 #include "api/rtc_error.h"
@@ -72,10 +71,9 @@ class PeerConnectionDataChannelOpenTest
       absl::string_view field_trials = "") {
     auto pc_wrapper = make_ref_counted<PeerConnectionTestWrapper>(
         "pc", &vss_, background_thread_.get(), background_thread_.get());
-    pc_wrapper->CreatePc(
-        {}, CreateBuiltinAudioEncoderFactory(),
-        CreateBuiltinAudioDecoderFactory(),
-        std::make_unique<FieldTrials>(CreateTestFieldTrials(field_trials)));
+    pc_wrapper->CreatePc({}, CreateBuiltinAudioEncoderFactory(),
+                         CreateBuiltinAudioDecoderFactory(),
+                         CreateTestFieldTrialsPtr(field_trials));
     return pc_wrapper;
   }
 

pc/peer_connection_encodings_integrationtest.cc

@@ -26,7 +26,6 @@
 #include "api/audio_codecs/builtin_audio_decoder_factory.h"
 #include "api/audio_codecs/builtin_audio_encoder_factory.h"
 #include "api/audio_options.h"
-#include "api/field_trials.h"
 #include "api/field_trials_view.h"
 #include "api/jsep.h"
 #include "api/make_ref_counted.h"
@@ -235,10 +234,9 @@ class PeerConnectionEncodingsIntegrationTest : public ::testing::Test {
       absl::string_view field_trials = "") {
     auto pc_wrapper = make_ref_counted<PeerConnectionTestWrapper>(
         "pc", &pss_, background_thread_.get(), background_thread_.get());
-    pc_wrapper->CreatePc(
-        {}, CreateBuiltinAudioEncoderFactory(),
-        CreateBuiltinAudioDecoderFactory(),
-        std::make_unique<FieldTrials>(CreateTestFieldTrials(field_trials)));
+    pc_wrapper->CreatePc({}, CreateBuiltinAudioEncoderFactory(),
+                         CreateBuiltinAudioDecoderFactory(),
+                         CreateTestFieldTrialsPtr(field_trials));
     return pc_wrapper;
   }
 

pc/peer_connection_field_trial_tests.cc

@@ -19,7 +19,6 @@
 #include "absl/strings/string_view.h"
 #include "api/enable_media_with_defaults.h"
 #include "api/environment/environment_factory.h"
-#include "api/field_trials.h"
 #include "api/media_types.h"
 #include "api/peer_connection_interface.h"
 #include "api/rtp_parameters.h"
@@ -66,8 +65,7 @@ class PeerConnectionFieldTrialTest : public ::testing::Test {
   void CreatePCFactory(absl::string_view field_trials) {
     PeerConnectionFactoryDependencies pcf_deps;
     pcf_deps.signaling_thread = Thread::Current();
-    pcf_deps.env = CreateEnvironment(
-        std::make_unique<FieldTrials>(CreateTestFieldTrials(field_trials)));
+    pcf_deps.env = CreateEnvironment(CreateTestFieldTrialsPtr(field_trials));
     pcf_deps.adm = FakeAudioCaptureModule::Create();
     EnableMediaWithDefaults(pcf_deps);
     pc_factory_ = CreateModularPeerConnectionFactory(std::move(pcf_deps));

pc/sdp_munging_detector_unittest.cc

@@ -128,8 +128,7 @@ class SdpMungingTest : public ::testing::Test {
       absl::string_view field_trials) {
     auto observer = std::make_unique<MockPeerConnectionObserver>();
     PeerConnectionDependencies pc_deps(observer.get());
-    pc_deps.trials =
-        std::make_unique<FieldTrials>(CreateTestFieldTrials(field_trials));
+    pc_deps.trials = CreateTestFieldTrialsPtr(field_trials);
     auto result =
         pc_factory_->CreatePeerConnectionOrError(config, std::move(pc_deps));
     EXPECT_TRUE(result.ok());

pc/sdp_offer_answer_unittest.cc

@@ -24,7 +24,6 @@
 #include "api/audio_codecs/builtin_audio_decoder_factory.h"
 #include "api/audio_codecs/builtin_audio_encoder_factory.h"
 #include "api/create_peerconnection_factory.h"
-#include "api/field_trials.h"
 #include "api/jsep.h"
 #include "api/media_types.h"
 #include "api/peer_connection_interface.h"
@@ -123,8 +122,7 @@ class SdpOfferAnswerTest : public ::testing::Test {
       absl::string_view field_trials) {
     auto observer = std::make_unique<MockPeerConnectionObserver>();
     PeerConnectionDependencies pc_deps(observer.get());
-    pc_deps.trials =
-        std::make_unique<FieldTrials>(CreateTestFieldTrials(field_trials));
+    pc_deps.trials = CreateTestFieldTrialsPtr(field_trials);
     auto result =
         pc_factory_->CreatePeerConnectionOrError(config, std::move(pc_deps));
     EXPECT_TRUE(result.ok());

pc/test/integration_test_helpers.h

@@ -34,7 +34,6 @@
 #include "api/crypto/crypto_options.h"
 #include "api/data_channel_interface.h"
 #include "api/dtls_transport_interface.h"
-#include "api/field_trials.h"
 #include "api/field_trials_view.h"
 #include "api/ice_transport_interface.h"
 #include "api/jsep.h"
@@ -1469,12 +1468,11 @@ class PeerConnectionIntegrationBaseTest : public ::testing::Test {
     if (it != field_trials_overrides_.end()) {
       field_trials = it->second;
     }
-    if (!client->Init(
-            options, &modified_config, std::move(dependencies), fss_.get(),
-            network_thread_.get(), worker_thread_.get(),
-            std::make_unique<FieldTrials>(CreateTestFieldTrials(field_trials)),
-            std::move(event_log_factory), reset_encoder_factory,
-            reset_decoder_factory, create_media_engine)) {
+    if (!client->Init(options, &modified_config, std::move(dependencies),
+                      fss_.get(), network_thread_.get(), worker_thread_.get(),
+                      CreateTestFieldTrialsPtr(field_trials),
+                      std::move(event_log_factory), reset_encoder_factory,
+                      reset_decoder_factory, create_media_engine)) {
       return nullptr;
     }
     return client;

test/BUILD.gn

@@ -154,6 +154,7 @@ rtc_library("create_test_field_trials") {
   sources = [ "create_test_field_trials.h" ]
   deps = [
     "../api:field_trials",
+    "//third_party/abseil-cpp/absl/base:nullability",
     "//third_party/abseil-cpp/absl/strings:string_view",
   ]
 

test/create_test_field_trials.h

@@ -10,6 +10,9 @@
 #ifndef TEST_CREATE_TEST_FIELD_TRIALS_H_
 #define TEST_CREATE_TEST_FIELD_TRIALS_H_
 
+#include <memory>
+
+#include "absl/base/nullability.h"
 #include "absl/strings/string_view.h"
 #include "api/field_trials.h"
 
@@ -20,9 +23,15 @@ namespace webrtc {
 // the command line flag.
 // Crashes if command line flag or the `s` are not a valid field trial string.
 //
-// The intention of this function is to be the default source of field trials
+// The intention of these functions is to be the default source of field trials
 // in tests so that tests always use the command line flag.
+// The behavior of these two functions is identical, they differ only in the
+// return types for convenience.
 FieldTrials CreateTestFieldTrials(absl::string_view s = "");
+inline absl_nonnull std::unique_ptr<FieldTrials> CreateTestFieldTrialsPtr(
+    absl::string_view s = "") {
+  return std::make_unique<FieldTrials>(CreateTestFieldTrials(s));
+}
 
 }  // namespace webrtc