Replace nl-unit-test with pigweed for messaging

.gn

@@ -25,6 +25,7 @@ script_executable = "python3"
 
 default_args = {
   pw_unit_test_AUTOMATIC_RUNNER = "$dir_pigweed/targets/host/run_test"
+  pw_unit_test_CONFIG = "//config/pw_unit_test:define_overrides"
 
   pw_build_PIP_CONSTRAINTS = [ "//scripts/setup/constraints.txt" ]
   pw_build_PIP_REQUIREMENTS = [ "//scripts/setup/requirements.build.txt" ]

config/pw_unit_test/BUILD.gn

@@ -0,0 +1,32 @@
+# Copyright (c) 2024 Project CHIP Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import("//build_overrides/build.gni")
+import("//build_overrides/chip.gni")
+import("//build_overrides/pigweed.gni")
+
+import("${chip_root}/build/chip/tests.gni")
+
+import("$dir_pw_build/target_types.gni")
+pw_source_set("define_overrides") {
+  public_configs = [ ":define_options" ]
+}
+
+config("define_options") {
+  if (chip_fake_platform && chip_link_tests) {
+    defines = [ "PW_UNIT_TEST_CONFIG_MEMORY_POOL_SIZE=65536" ]
+  } else {
+    defines = [ "PW_UNIT_TEST_CONFIG_MEMORY_POOL_SIZE=16384" ]
+  }
+}

src/messaging/tests/BUILD.gn

@@ -14,7 +14,6 @@
 
 import("//build_overrides/build.gni")
 import("//build_overrides/chip.gni")
-import("//build_overrides/nlunit_test.gni")
 
 import("${chip_root}/build/chip/chip_test_suite.gni")
 import("${chip_root}/src/app/icd/icd.gni")
@@ -38,15 +37,9 @@ static_library("helpers") {
     "${chip_root}/src/transport",
     "${chip_root}/src/transport/tests:helpers",
   ]
-
-  # MessagingContext exposes nl-test compatible setup/teardown functions, specifically
-  # they return nltest specific SUCCESS/FAILURE constants hence this dependency.
-  #
-  # Once all tests are moved to pw_unittest/gtest, this dependency should be removed
-  public_deps = [ "${nlunit_test_root}:nlunit-test" ]
 }
 
-chip_test_suite_using_nltest("tests") {
+chip_test_suite("tests") {
   output_name = "libMessagingLayerTests"
 
   test_sources = [
@@ -73,12 +66,10 @@ chip_test_suite_using_nltest("tests") {
     "${chip_root}/src/lib/core",
     "${chip_root}/src/lib/support",
     "${chip_root}/src/lib/support:test_utils",
-    "${chip_root}/src/lib/support:testing_nlunit",
     "${chip_root}/src/messaging",
     "${chip_root}/src/protocols",
     "${chip_root}/src/transport",
     "${chip_root}/src/transport/raw/tests:helpers",
-    "${nlunit_test_root}:nlunit-test",
   ]
 
   if (chip_enable_icd_server) {

src/messaging/tests/MessagingContext.h

@@ -32,8 +32,6 @@
 #include <transport/tests/LoopbackTransportManager.h>
 #include <transport/tests/UDPTransportManager.h>
 
-#include <nlunit-test.h>
-
 #include <vector>
 
 namespace chip {
@@ -98,6 +96,8 @@ class MessagingContext : public PlatformMemoryUser
         mInitialized(false), mAliceAddress(Transport::PeerAddress::UDP(GetAddress(), CHIP_PORT + 1)),
         mBobAddress(Transport::PeerAddress::UDP(GetAddress(), CHIP_PORT))
     {}
+    // TODO Replace VerifyOrDie with Pigweed assert after transition app/tests to Pigweed.
+    // TODO Currently src/app/icd/server/tests is using MessagingConetext as dependency.
     ~MessagingContext() { VerifyOrDie(mInitialized == false); }
 
     // Whether Alice and Bob are initialized, must be called before Init