modules: Add fff mocking framework

Issue #38643

Introduce a more powerful and well established mocking framework
into Zephyr. It also allows running the actual FFF tests using the
zephyr SDK and ztest framework to ensure compatibility.

As per TSC meeting, the fff.h header was directly added to
subsys/testsuite/include/. As per the guidelines, the file is exactly
the same as it is in FFF's library, but re-styled with clang-format.

The west.yml entry was added using the "ci" group and filtered by
default. (note that the tests will break until the CI actually
specifies that the group is needed).

Signed-off-by: Yuval Peress <[email protected]>

Author: Yuval Peress

modules/Kconfig

@@ -67,6 +67,9 @@ comment "loramac-node module not available."
 comment "CANopenNode module not available."
 	depends on !ZEPHYR_CANOPENNODE_MODULE
 
+comment "FFF module not available."
+	depends on !ZEPHYR_FFF_MODULE
+
 # This ensures that symbols are available in Kconfig for dependency checking
 # and referencing, while keeping the settings themselves unavailable when the
 # modules are not present in the workspace

modules/fff/CMakeLists.txt

@@ -0,0 +1,24 @@
+# Copyright (c) 2021 Google LLC
+#
+# SPDX-License-Identifier: Apache-2.0
+
+
+if(CONFIG_FFF_TEST)
+  # Add the FFF C test suites as ztest suites
+  message("CONFIG_FFF_TEST_C=${CONFIG_FFF_TEST_C}")
+  message("CONFIG_FFF_TEST_GLOBAL_C=${CONFIG_FFF_TEST_GLOBAL_C}")
+  zephyr_library()
+  zephyr_include_directories(
+      include
+      "${ZEPHYR_CURRENT_MODULE_DIR}"
+      "${ZEPHYR_CURRENT_MODULE_DIR}/test"
+  )
+  if(DEFINED CONFIG_FFF_TEST_C)
+    zephyr_library_sources("${ZEPHYR_CURRENT_MODULE_DIR}/test/fff_test_c.c")
+  elseif(DEFINED CONFIG_FFF_TEST_GLOBAL_C)
+    zephyr_library_sources(
+        "${ZEPHYR_CURRENT_MODULE_DIR}/test/fff_test_global_c.c"
+        "${ZEPHYR_CURRENT_MODULE_DIR}/test/global_fakes.c"
+    )
+  endif()
+endif()

modules/fff/Kconfig

@@ -0,0 +1,26 @@
+# Copyright (c) 2021 Google LLC
+# SPDX-License-Identifier: Apache-2.0
+
+config ZEPHYR_FFF_MODULE
+	bool
+
+config FFF_TEST
+	bool "FFF Test suite"
+	help
+	  Enable the FFF test suite. This should really only be called from the tests for FFF under
+	  tests/ztest/mock_fff/. It brings in the test sources from the upstream FFF module.
+
+if FFF_TEST
+
+choice FFF_TEST
+	prompt "The type of FFF test to bring in"
+
+config FFF_TEST_C
+	bool "Compile the FFF default C test suite as a zephyr library"
+
+config FFF_TEST_GLOBAL_C
+	bool "Compile the FFF global C test suite as a zephyr library"
+
+endchoice # FFF_TEST
+
+endif # FFF_TEST

modules/fff/include/c_test_framework.h

@@ -0,0 +1,27 @@
+/* Copyright (c) 2021 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef MODULES_FFF_TEST_INCLUDE_C_TEST_FRAMEWORK_H_
+#define MODULES_FFF_TEST_INCLUDE_C_TEST_FRAMEWORK_H_
+
+#include <ztest.h>
+#include <sys/printk.h>
+
+void setup(void);
+void fff_test_suite(void);
+
+#define PRINTF(FMT, args...)
+#define TEST_F(SUITE, NAME) __attribute__((unused)) static void test_##NAME(void)
+#define RUN_TEST(SUITE, NAME)                                                                      \
+	do {                                                                                       \
+		ztest_test_suite(                                                                  \
+			SUITE##_##NAME,                                                            \
+			ztest_unit_test_setup_teardown(test_##NAME, setup, unit_test_noop));       \
+		ztest_run_test_suite(SUITE##_##NAME);                                              \
+	} while (0)
+#define ASSERT_EQ(A, B) zassert_equal((A), (B), NULL)
+#define ASSERT_TRUE(A) zassert_true((A), NULL)
+
+#endif /* MODULES_FFF_TEST_INCLUDE_C_TEST_FRAMEWORK_H_ */

subsys/testsuite/include/fff.h

@@ -0,0 +1,9 @@
+# Copyright 2021 Google LLC
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(mock_fff)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})

tests/ztest/mock_fff/CMakeLists.txt

@@ -0,0 +1,3 @@
+CONFIG_ZTEST=y
+CONFIG_FFF_TEST=y
+CONFIG_FFF_TEST_C=y

tests/ztest/mock_fff/prj.conf

@@ -0,0 +1,3 @@
+CONFIG_ZTEST=y
+CONFIG_FFF_TEST=y
+CONFIG_FFF_TEST_GLOBAL_C=y

tests/ztest/mock_fff/prj_global.conf

@@ -0,0 +1,14 @@
+/* Copyright 2021 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <ztest.h>
+#include <fff.h>
+
+#include <c_test_framework.h>
+
+void test_main(void)
+{
+	fff_test_suite();
+}

tests/ztest/mock_fff/src/main.c

@@ -0,0 +1,12 @@
+tests:
+  testing.ztest.mock_fff:
+    filter: CONFIG_ZEPHYR_FFF_MODULE
+    tags: test_framework
+    integration_platforms:
+      - native_posix
+  testing.ztest.mock_fff_global:
+    filter: CONFIG_ZEPHYR_FFF_MODULE
+    tags: test_framework
+    extra_args: CONF_FILE=prj_global.conf
+    integration_platforms:
+      - native_posix