pw_unit_test#

pw_unit_test provides a GoogleTest-compatible unit testing API for Pigweed. The default implementation is the embedded-friendly pw_unit_test:light backend. Upstream GoogleTest may be used as well (see Using upstream GoogleTest).

Note

This documentation is currently incomplete.

pw_unit_test:light: GoogleTest for Embedded#

pw_unit_test:light implements a subset of GoogleTest with lightweight, embedded-friendly primitives. It is also highly portable and can run on almost any system from bare metal to a full-fledged desktop OS. It does this by offloading the responsibility of test reporting and output to the underlying system, communicating its results through a common interface. Unit tests can be written once and run under many different environments, empowering developers to write robust, high quality code.

pw_unit_test:light usage is the same as GoogleTest; refer to the GoogleTest documentation for examples of how to define unit test cases.

pw_unit_test:light is still under development and lacks many features expected in a complete testing framework; nevertheless, it is already used heavily within Pigweed.

Note

Many of GoogleTest’s more advanced features are not yet implemented. Missing features include:

Any GoogleMock features (e.g. EXPECT_THAT)
Floating point comparison macros (e.g. EXPECT_FLOAT_EQ)
Death tests (e.g. EXPECT_DEATH); EXPECT_DEATH_IF_SUPPORTED does nothing but silently passes
Value-parameterized tests

To request a feature addition, please let us know.

See Using upstream GoogleTest below for information about using upstream GoogleTest instead.

The EventHandler interface#

The EventHandler class in public/pw_unit_test/event_handler.h defines the interface through which pw_unit_test:light communicates the results of its test runs. A platform using the pw_unit_test:light backend must register an event handler with the unit testing framework to receive test output.

As the framework runs tests, it calls the event handler’s callback functions to notify the system of various test events. The system can then choose to perform any necessary handling or aggregation of these events, and report them back to the developer.

Predefined event handlers#

Pigweed provides some standard event handlers upstream to simplify the process of getting started using pw_unit_test:light. All event handlers provide for GoogleTest-style output using the shared pw::unit_test::GoogleTestStyleEventHandler base.

[==========] Running all tests.
[ RUN      ] Status.Default
[       OK ] Status.Default
[ RUN      ] Status.ConstructWithStatusCode
[       OK ] Status.ConstructWithStatusCode
[ RUN      ] Status.AssignFromStatusCode
[       OK ] Status.AssignFromStatusCode
[ RUN      ] Status.CompareToStatusCode
[       OK ] Status.CompareToStatusCode
[ RUN      ] Status.Ok_OkIsTrue
[       OK ] Status.Ok_OkIsTrue
[ RUN      ] Status.NotOk_OkIsFalse
[       OK ] Status.NotOk_OkIsFalse
[ RUN      ] Status.KnownString
[       OK ] Status.KnownString
[ RUN      ] Status.UnknownString
[       OK ] Status.UnknownString
[==========] Done running all tests.
[  PASSED  ] 8 test(s).

class GoogleTestStyleEventHandler#: Provides GoogleTest-style output for pw_unit_test:light events. Must be extended to define how to output the results.

class SimplePrintingEventHandler : public GoogleTestStyleEventHandler #: An event handler that writes GoogleTest-style output to a specified sink.

class LoggingEventHandler : public GoogleTestStyleEventHandler #: An event handler which uses the pw_log module to output test results, to integrate with the system’s existing logging setup.

class PrintfEventHandler : public GoogleTestStyleEventHandler #: A C++14-compatible event handler that uses std::printf to output test results.

Test filtering#

Pigweed AI summary: The article discusses the use of filters in C++17 for running a subset of registered unit tests in a test framework. This is particularly useful when multiple tests are bundled into a single application image. Currently, only a test suite filter is supported, which can be set by calling pw::unit_test::SetTestSuitesToRun with a list of suite names. It is important to note that test filtering is only supported in C++17.

If using C++17, filters can be set on the test framework to run only a subset of the registered unit tests. This is useful when many tests are bundled into a single application image.

Currently, only a test suite filter is supported. This is set by calling pw::unit_test::SetTestSuitesToRun with a list of suite names.

Note

Test filtering is only supported in C++17.

Tests in static libraries#

The linker usually ignores tests linked through a static library (.a file). This is because test registration relies on the test instance’s static constructor adding itself to a global list of tests. When linking against a static library, static constructors in an object file will be ignored unless at least one entity in that object file is linked.

Pigweed’s pw_unit_test implementation provides the PW_UNIT_TEST_LINK_FILE_CONTAINING_TEST macro to support running tests in a static library.

PW_UNIT_TEST_LINK_FILE_CONTAINING_TEST(test_suite_name, test_name)#: Ensures tests in a static library are linked and executed. Provide the test suite name and test name for one test in the file linked into a static library. Any test in the file may be used, but it is recommended to use the first for consistency. The test must be in a static library that is a dependency of this target. Referring to a test that does not exist causes a linker error.

Running tests#

To run unit tests, link the tests into a single binary with the unit testing framework, configure the backend if needed, and call the RUN_ALL_TESTS macro.

The following example shows how to write a main function that runs pw_unit_test with the light backend.

#include "gtest/gtest.h"

// pw_unit_test:light requires an event handler to be configured.
#include "pw_unit_test/simple_printing_event_handler.h"

void WriteString(const std::string_view& string, bool newline) {
  printf("%s", string.data());
  if (newline) {
    printf("\n");
  }
}

int main() {
  // The following line has no effect with pw_unit_test_light, but makes this
  // test compatible with upstream GoogleTest.
  testing::InitGoogleTest();

  // Since we are using pw_unit_test:light, set up an event handler.
  pw::unit_test::SimplePrintingEventHandler handler(WriteString);
  pw::unit_test::RegisterEventHandler(&handler);
  return RUN_ALL_TESTS();
}

Build system integration#

pw_unit_test integrates directly into Pigweed’s GN and CMake build systems.

The pw_unit_test module provides a few optional libraries to simplify setup:

simple_printing_event_handler: When running tests, output test results as plain text over pw_sys_io.
simple_printing_main: Implements a main() function that simply runs tests using the simple_printing_event_handler.
logging_event_handler: When running tests, log test results as plain text using pw_log (ensure your target has set a pw_log backend).
logging_main: Implements a main() function that simply runs tests using the logging_event_handler.

GN#

To define simple unit tests, set the pw_unit_test_MAIN build variable to a target which configures the test framework as described in the Running tests section, and use the pw_test template to register your test code.

import("$dir_pw_unit_test/test.gni")

pw_test("foo_test") {
  sources = [ "foo_test.cc" ]
}

pw_test template#

Pigweed AI summary: The "pw_test" template defines a unit test suite with sub-targets for building and running tests. It accepts GN executable arguments and has optional arguments for enabling or disabling tests, specifying dependencies, and setting environment variables. An example usage is provided.

pw_test defines a single unit test suite. It creates several sub-targets.

<target_name>: The test suite within a single binary. The test code is linked against the target set in the build arg pw_unit_test_MAIN.
<target_name>.run: If pw_unit_test_AUTOMATIC_RUNNER is set, this target runs the test as part of the build.
<target_name>.lib: The test sources without pw_unit_test_MAIN.

Arguments

All GN executable arguments are accepted and forwarded to the underlying pw_executable.
enable_if: Boolean indicating whether the test should be built. If false, replaces the test with an empty target. Default true.
source_gen_deps: List of target labels that generate source files used by this test. The labels must meet the constraints of GN’s get_target_outputs, namely they must have been previously defined in the current file. This argument is required if a test uses generated source files and enable_if can evaluate to false.
test_main: Target label to add to the tests’s dependencies to provide the main() function. Defaults to pw_unit_test_MAIN. Set to "" if main() is implemented in the test’s sources.
test_automatic_runner_args: Array of args to pass to automatic test runner. Defaults to pw_unit_test_AUTOMATIC_RUNNER_ARGS.
envvars: Array of "key=value" strings representing environment variables to set when invoking the automatic test runner.

Example

import("$dir_pw_unit_test/test.gni")

pw_test("large_test") {
  sources = [ "large_test.cc" ]
  enable_if = device_has_1m_flash
}

pw_test_group template#

Pigweed AI summary: The "pw_test_group" template defines a collection of tests or other test groups, creating several sub-targets such as the test group itself, a target that runs all tests in the group and its dependencies, the sources of all tests in the group and its dependencies, and a target that bundles all tests into a single binary. The template takes arguments such as a list of "pw_test" targets in the group and a list of other "pw_test_group" targets on which this one depends.

pw_test_group defines a collection of tests or other test groups. It creates several sub-targets:

<target_name>: The test group itself.
<target_name>.run: If pw_unit_test_AUTOMATIC_RUNNER is set, this target runs all of the tests in the group and all of its group dependencies individually.
<target_name>.lib: The sources of all of the tests in this group and its dependencies.
<target_name>.bundle: All of the tests in the group and its dependencies bundled into a single binary.
<target_name>.bundle.run: Automatic runner for the test bundle.

Arguments

tests: List of the pw_test targets in the group.
group_deps: List of other pw_test_group targets on which this one depends.
enable_if: Boolean indicating whether the group target should be created. If false, an empty GN group is created instead. Default true.

Example

import("$dir_pw_unit_test/test.gni")

pw_test_group("tests") {
  tests = [
    ":bar_test",
    ":foo_test",
  ]
}

pw_test("foo_test") {
  # ...
}

pw_test("bar_test") {
  # ...
}

pw_facade_test template#

Pigweed AI summary: Pigweed facade test templates allow for individual unit tests to be built under the current device target configuration while overriding specific build arguments. This enables tests to replace a facade's backend for the purpose of testing the facade layer. Facade tests are disabled by default, but can be enabled by setting the GN arg pw_unit_test_FACADE_TESTS_ENABLED to true. However, facade tests can be costly as each test triggers a re-build of every dependency, and some configurations may not be compatible with the target

Pigweed facade test templates allow individual unit tests to build under the current device target configuration while overriding specific build arguments. This allows these tests to replace a facade’s backend for the purpose of testing the facade layer.

Facade tests are disabled by default. To build and run facade tests, set the GN arg pw_unit_test_FACADE_TESTS_ENABLED to true.

Warning

Facade tests are costly because each facade test will trigger a re-build of every dependency of the test. While this sounds excessive, it’s the only technically correct way to handle this type of test.

Warning

Some facade test configurations may not be compatible with your target. Be careful when running a facade test on a system that heavily depends on the facade being tested.

Build arguments#

pw_unit_test_GOOGLETEST_BACKEND <source_set>#

The GoogleTest implementation to use for Pigweed unit tests. This library provides “gtest/gtest.h” and related headers. Defaults to pw_unit_test:light, which implements a subset of GoogleTest.

Type: string (GN path to a source set) Usage: toolchain-controlled only

pw_unit_test_MAIN <source_set>#

Implementation of a main function for pw_test unit test binaries.

Type: string (GN path to a source set) Usage: toolchain-controlled only

pw_unit_test_AUTOMATIC_RUNNER <executable>#

Path to a test runner to automatically run unit tests after they are built.

If set, a pw_test target’s <target_name>.run action will invoke the test runner specified by this argument, passing the path to the unit test to run. If this is unset, the pw_test target’s <target_name>.run step will do nothing.

Targets that don’t support parallelized execution of tests (e.g. a on-device test runner that must flash a device and run the test in serial) should set pw_unit_test_POOL_DEPTH to 1.

Type: string (name of an executable on the PATH, or path to an executable) Usage: toolchain-controlled only

pw_unit_test_AUTOMATIC_RUNNER_ARGS <args>#

An optional list of strings to pass as args to the test runner specified by pw_unit_test_AUTOMATIC_RUNNER.

Type: list of strings (args to pass to pw_unit_test_AUTOMATIC_RUNNER) Usage: toolchain-controlled only

pw_unit_test_AUTOMATIC_RUNNER_TIMEOUT <timeout_seconds>#

An optional timeout to apply when running the automatic runner. Timeout is in seconds. Defaults to empty which means no timeout.

Type: string (number of seconds to wait before killing test runner) Usage: toolchain-controlled only

pw_unit_test_POOL_DEPTH <pool_depth>#

The maximum number of unit tests that may be run concurrently for the current toolchain. Setting this to 0 disables usage of a pool, allowing unlimited parallelization.

Note: A single target with two toolchain configurations (e.g. release/debug): will use two separate test runner pools by default. Set pw_unit_test_POOL_TOOLCHAIN to the same toolchain for both targets to merge the pools and force serialization.

Type: integer Usage: toolchain-controlled only

pw_unit_test_POOL_TOOLCHAIN <toolchain>#

The toolchain to use when referring to the pw_unit_test runner pool. When this is disabled, the current toolchain is used. This means that every toolchain will use its own pool definition. If two toolchains should share the same pool, this argument should be by one of the toolchains to the GN path of the other toolchain.

Type: string (GN path to a toolchain) Usage: toolchain-controlled only

pw_unit_test_EXECUTABLE_TARGET_TYPE <template name>#

The name of the GN target type used to build pw_unit_test executables.

Type: string (name of a GN template) Usage: toolchain-controlled only

pw_unit_test_EXECUTABLE_TARGET_TYPE_FILE <gni file path>#

The path to the .gni file that defines pw_unit_test_EXECUTABLE_TARGET_TYPE.

If pw_unit_test_EXECUTABLE_TARGET_TYPE is not the default of pw_executable, this .gni file is imported to provide the template definition.

Type: string (path to a .gni file) Usage: toolchain-controlled only

pw_unit_test_FACADE_TESTS_ENABLED <boolean>#: Controls whether to build and run facade tests. Facade tests add considerably to build time, so they are disabled by default.

CMake#

pw_add_test function#

Pigweed AI summary: The pw_add_test function creates a unit test suite with several sub-targets, including a library target and a standalone executable. The function requires a name argument and offers optional arguments for source files, header files, and compile options. An example usage is provided.

pw_add_test declares a single unit test suite. It creates several sub-targets.

{NAME} depends on ${NAME}.run if pw_unit_test_AUTOMATIC_RUNNER is set, else it depends on ${NAME}.bin
{NAME}.lib contains the provided test sources as a library target, which can then be linked into a test executable.
{NAME}.bin is a standalone executable which contains only the test sources specified in the pw_unit_test_template.
{NAME}.run which runs the unit test executable after building it if pw_unit_test_AUTOMATIC_RUNNER is set, else it fails to build.

Required Arguments

NAME: name to use for the produced test targets specified above

Optional Arguments

SOURCES - source files for this library
HEADERS- header files for this library
PRIVATE_DEPS- private pw_target_link_targets arguments
PRIVATE_INCLUDES- public target_include_directories argument
PRIVATE_DEFINES- private target_compile_definitions arguments
PRIVATE_COMPILE_OPTIONS- private target_compile_options arguments
PRIVATE_LINK_OPTIONS- private target_link_options arguments

Example

include($ENV{PW_ROOT}/pw_unit_test/test.cmake)

pw_add_test(my_module.foo_test
  SOURCES
    foo_test.cc
  PRIVATE_DEPS
    my_module.foo
)

pw_add_test_group function#

Pigweed AI summary: The pw_add_test_group function creates a collection of tests or test groups with several sub-targets. The sub-targets include dependencies on other targets and the creation of executable and library targets. Required arguments for this function include the name of the executable target and the tests to be included in the test bundle. An example usage of this function is provided.

pw_add_test_group defines a collection of tests or other test groups. It creates several sub-targets:

{NAME} depends on ${NAME}.run if pw_unit_test_AUTOMATIC_RUNNER is set, else it depends on ${NAME}.bin.
{NAME}.bundle depends on ${NAME}.bundle.run if pw_unit_test_AUTOMATIC_RUNNER is set, else it depends on ${NAME}.bundle.bin.
{NAME}.lib depends on ${NAME}.bundle.lib.
{NAME}.bin depends on the provided TESTS’s <test_dep>.bin targets.
{NAME}.run depends on the provided TESTS’s <test_dep>.run targets if pw_unit_test_AUTOMATIC_RUNNER is set, else it fails to build.
{NAME}.bundle.lib contains the provided tests bundled as a library target, which can then be linked into a test executable.
{NAME}.bundle.bin standalone executable which contains the bundled tests.
{NAME}.bundle.run runs the {NAME}.bundle.bin test bundle executable after building it if pw_unit_test_AUTOMATIC_RUNNER is set, else it fails to build.

Required Arguments

NAME - The name of the executable target to be created.
TESTS - pw_add_test targets and pw_add_test_group bundles to be included in this test bundle

Example

include($ENV{PW_ROOT}/pw_unit_test/test.cmake)

pw_add_test_group(tests
  TESTS
    bar_test
    foo_test
)

pw_add_test(foo_test
  # ...
)

pw_add_test(bar_test
  # ...
)

Build arguments#

pw_unit_test_GOOGLETEST_BACKEND <target>#

The GoogleTest implementation to use for Pigweed unit tests. This library provides “gtest/gtest.h” and related headers. Defaults to pw_unit_test.light, which implements a subset of GoogleTest.

Type: string (CMake target name) Usage: toolchain-controlled only

pw_unit_test_AUTOMATIC_RUNNER <executable>#

Path to a test runner to automatically run unit tests after they are built.

If set, a pw_test target’s ${NAME} and ${NAME}.run targets will invoke the test runner specified by this argument, passing the path to the unit test to run. If this is unset, the pw_test target’s ${NAME} will only build the unit test(s) and ${NAME}.run will fail to build.

Type: string (name of an executable on the PATH, or path to an executable) Usage: toolchain-controlled only

pw_unit_test_AUTOMATIC_RUNNER_ARGS <args>#

An optional list of strings to pass as args to the test runner specified by pw_unit_test_AUTOMATIC_RUNNER.

Type: list of strings (args to pass to pw_unit_test_AUTOMATIC_RUNNER) Usage: toolchain-controlled only

pw_unit_test_AUTOMATIC_RUNNER_TIMEOUT_SECONDS <timeout_seconds>#

An optional timeout to apply when running the automatic runner. Timeout is in seconds. Defaults to empty which means no timeout.

Type: string (number of seconds to wait before killing test runner) Usage: toolchain-controlled only

pw_unit_test_ADD_EXECUTABLE_FUNCTION <function name>#

The name of the CMake function used to build pw_unit_test executables. The provided function must take a NAME and a TEST_LIB argument which are the expected name of the executable target and the target which provides the unit test(s).

Type: string (name of a CMake function) Usage: toolchain-controlled only

pw_unit_test_ADD_EXECUTABLE_FUNCTION_FILE <cmake file path>#

The path to the .cmake file that defines pw_unit_test_ADD_EXECUTABLE_FUNCTION.

Type: string (path to a .cmake file) Usage: toolchain-controlled only

Bazel#

load("//pw_build:pigweed.bzl", "pw_cc_test")

pw_cc_test(
    name = "foo_test",
    srcs = ["foo_test.cc"],
}

pw_cc_test rule#

Pigweed AI summary: The "pw_cc_test" rule is a wrapper for "cc_test" that provides some defaults and supports all the arguments recognized by "cc_test". It allows tests to be enabled or disabled using "target_compatible_with". An example of a test that is skipped when using upstream GoogleTest is provided.

pw_cc_test is a wrapper for cc_test that provides some defaults, such as a dep on @pigweed_config//:pw_unit_test_main. It supports and passes through all the arguments recognized by cc_test. Notably, tests can be enabled or disabled using target_compatible_with. For example, the following test is skipped when using upstream GoogleTest:

load("//pw_build:pigweed.bzl", "pw_cc_test")

pw_cc_test(
    name = "no_upstream_test",
    srcs = ["no_upstream_test.cc"],
     target_compatible_with = select({
         "//pw_unit_test:light_setting": [],
         "//conditions:default": ["@platforms//:incompatible"],
     }),
}

Build arguments#

pw_unit_test_googletest_backend <target>#

The GoogleTest implementation to use for Pigweed unit tests. This library provides “gtest/gtest.h” and related headers. Defaults to "@pigweed//pw_unit_test:light", which implements a subset of GoogleTest.

Type: string (Bazel target label) Usage: toolchain-controlled only

pw_unit_test_main <target>#

Implementation of a main function for pw_cc_test unit test binaries.

Type: string (Bazel target label) Usage: toolchain-controlled only

Serial test runner#

To accelerate automated unit test bringup for devices with plain-text logging, this module provides a serial-based test runner that triggers a device flash and evaluates whether the test passed or failed based on the produced output.

pw_unit_test.serial_test_runner#

This library facilitates automating unit tests on devices with serial ports.

This library assumes that the on-device test runner will emit the test results as plain-text over a serial port, and tests will be triggered by a pre-defined input (DEFAULT_TEST_START_CHARACTER) over the same serial port that results are emitted from.

class pw_unit_test.serial_test_runner.SerialTestingDevice#

A device that supports automated testing via parsing serial output.

abstract baud_rate() → int#

Returns the baud rate to use when connecting to this device.

Raises:: DeviceNotFound – This device is no longer available.

abstract load_binary(binary: Path) → None#

Flashes the specified binary to this device.

Raises:

DeviceNotFound – This device is no longer available.
FlashingFailure – The binary could not be flashed.

abstract serial_port() → str#

Returns the name of the com port this device is enumerated on.

Raises:: DeviceNotFound – This device is no longer available.

pw_unit_test.serial_test_runner.run_device_test(device: ~pw_unit_test.serial_test_runner.SerialTestingDevice, binary: ~pathlib.Path, test_timeout: float, logger: ~logging.Logger = <Logger serial_test_runner (WARNING)>) → bool#

Runs tests on a device.

When a unit test run fails, results will be logged as an error.

Parameters:

device – The device to run tests on.
binary – The binary containing tests that will be flashed to the device.
test_timeout – If the device stops producing output longer than this timeout, the test will be considered stuck and the test will be aborted.

Returns:

True if all tests passed.

Setup#

Pigweed AI summary: To add support for a new device, you need to implement a "SerialTestingDevice" class for your device. Additionally, you should configure your on-device firmware to wait for the unit tests to run until the "DEFAULT_TEST_START_CHARACTER" is sent over the serial connection.

To add support for a new device, implement a SerialTestingDevice class for your device, and then configure your on-device firmware to wait to run unit tests until DEFAULT_TEST_START_CHARACTER is sent over the serial connection.

RPC service#

pw_unit_test provides an RPC service which runs unit tests on demand and streams the results back to the client. The service is defined in pw_unit_test_proto/unit_test.proto, and implemented by the GN target $dir_pw_unit_test:rpc_service.

The RPC service is primarily intended for use with the default pw_unit_test:light backend. It has some support for the GoogleTest backend, however some features (such as test suite filtering) are missing.

To set up RPC-based unit tests in your application, instantiate a pw::unit_test::UnitTestService and register it with your RPC server.

#include "pw_rpc/server.h"
#include "pw_unit_test/unit_test_service.h"

// Server setup; refer to pw_rpc docs for more information.
pw::rpc::Channel channels[] = {
 pw::rpc::Channel::Create<1>(&my_output),
};
pw::rpc::Server server(channels);

pw::unit_test::UnitTestService unit_test_service;

void RegisterServices() {
  server.RegisterService(unit_test_services);
}

All tests flashed to an attached device can be run via python by calling pw_unit_test.rpc.run_tests() with a RPC client services object that has the unit testing RPC service enabled. By default, the results will output via logging.

from pw_hdlc.rpc import HdlcRpcClient
from pw_unit_test.rpc import run_tests

PROTO = Path(os.environ['PW_ROOT'],
             'pw_unit_test/pw_unit_test_proto/unit_test.proto')

client = HdlcRpcClient(serial.Serial(device, baud), PROTO)
run_tests(client.rpcs())

pw_unit_test.rpc#

Utilities for running unit tests over Pigweed RPC.

class pw_unit_test.rpc.EventHandler#

abstract run_all_tests_end(passed_tests: int, failed_tests: int) → None#: Called after the test run is complete.

abstract run_all_tests_start() → None#: Called before all tests are run.

abstract test_case_disabled(test_case: TestCase) → None#: Called when a disabled test case is encountered.

abstract test_case_end(test_case: TestCase, result: TestCaseResult) → None#: Called when a test case completes with its overall result.

abstract test_case_expect(test_case: TestCase, expectation: TestExpectation) → None#: Called after each expect/assert statement within a test case.

abstract test_case_start(test_case: TestCase) → None#: Called when a new test case is started.

pw_unit_test.rpc.run_tests(rpcs: ~pw_rpc.client.Services, report_passed_expectations: bool = False, test_suites: ~typing.Iterable[str] = (), event_handlers: ~typing.Iterable[~pw_unit_test.rpc.EventHandler] = (<pw_unit_test.rpc.LoggingEventHandler object>, ), timeout_s: ~typing.Optional[~typing.Union[~pw_rpc.callback_client.call.UseDefault, float]] = UseDefault.VALUE) → bool#

Runs unit tests on a device over Pigweed RPC.

Calls each of the provided event handlers as test events occur, and returns True if all tests pass.

Module Configuration Options#

The following configurations can be adjusted via compile-time configuration of this module.

PW_UNIT_TEST_CONFIG_EVENT_BUFFER_SIZE#: The size of the event buffer that the UnitTestService contains. This buffer is used to encode events. By default this is set to 128 bytes.

PW_UNIT_TEST_CONFIG_MEMORY_POOL_SIZE#: The size of the memory pool to use for test fixture instances. By default this is set to 16K.

Using upstream GoogleTest#

Upstream GoogleTest may be used as the backend for pw_unit_test. A clone of the GoogleTest repository is required. See the third_party/googletest documentation for details.

When using upstream GoogleTest as the backend, the pw::unit_test::GoogleTestHandlerAdapter can be used in conjunction with the above mentioned EventHandler Interface and Predefined event handlers. Included with this class is an implementation of RegisterEventHandler that wraps event handlers in an adapter. This allows the main functions written for pw_unit_test:light to work with upstream GoogleTest without modification, as shown below.

#include "gtest/gtest.h"
#include "pw_unit_test/logging_event_handler.h"

int main() {
  testing::InitGoogleTest();
  pw::unit_test::LoggingEventHandler logger;
  pw::unit_test::RegisterEventHandler(&logger);
  return RUN_ALL_TESTS();
}

class GoogleTestHandlerAdapter#: A GoogleTest Event Listener that fires GoogleTest emitted events to an appropriate EventHandler.