unit-tests: implement the unit-testing framework

This set of patches adds a simple unit-testing framework to Busybox

unit-tests: add some helper macros for unit-test framework implementation
unit-tests: implement the unit-testing framework
unit-tests: add basic documentation on writing the unit test cases
unit-tests: modify the Makefile 'test' target to run unit-tests too
unit-tests: add two example test cases
unit-tests: modify the existing strrstr test code to use the unit-test framework

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

8 files changed, 335 insertions, 12 deletions

diff --git a/Config.in b/Config.in
index b6eaea5..b83beb5 100644
--- a/Config.in
+++ b/Config.in
@@ -675,6 +675,14 @@ config DEBUG_PESSIMIZE
 	  in a much bigger executable that more closely matches the source
 	  code.
 
+config UNIT_TEST
+	bool "Build unit tests"
+	default n
+	help
+	  Say Y here if you want to build unit tests (both the framework and
+	  test cases) as a Busybox applet. This results in bigger code, so you
+	  probably don't want this option in production builds.
+
 config WERROR
 	bool "Abort compilation on any warning"
 	default n
diff --git a/Makefile.custom b/Makefile.custom
index 8c95ef2..f8a1283 100644
--- a/Makefile.custom
+++ b/Makefile.custom
@@ -55,7 +55,11 @@ endif
 # (cp -pPR is POSIX-compliant (cp -dpR or cp -a would not be))
 .PHONY: check
 .PHONY: test
+ifeq ($(CONFIG_UNIT_TEST),y)
+UNIT_CMD = ./busybox unit
+endif
 check test: busybox busybox.links
+	$(UNIT_CMD)
 	test -d $(objtree)/testsuite || cp -pPR $(srctree)/testsuite $(objtree)
 	bindir=$(objtree) srcdir=$(srctree)/testsuite \
 	$(SHELL) -c "cd $(objtree)/testsuite && $(srctree)/testsuite/runtest $(if $(KBUILD_VERBOSE:0=),-v)"
diff --git a/docs/unit-tests.txt b/docs/unit-tests.txt
new file mode 100644
index 0000000..0fb5220
--- /dev/null
+++ b/docs/unit-tests.txt
@@ -0,0 +1,50 @@
+Busybox unit test framework
+===========================
+
+This document describes what you need to do to write test cases using the
+Busybox unit test framework.
+
+
+Building unit tests
+-------------------
+
+The framework and all tests are built as a regular Busybox applet if option
+CONFIG_UNIT_TEST (found in General Configuration -> Debugging Options) is set.
+
+
+Writing test cases
+------------------
+
+Unit testing interface can be found in include/bbunit.h.
+
+Tests can be placed in any .c file in Busybox tree - preferably right next to
+the functions they test. Test cases should be enclosed within an #if, and
+should start with BBUNIT_DEFINE_TEST macro and end with BBUNIT_ENDTEST within
+the test curly brackets. If an assertion fails the test ends immediately, ie.
+the following assertions will not be reached. Any code placed after
+BBUNIT_ENDTEST is executed regardless of the test result. Here's an example:
+
+#if ENABLE_UNIT_TEST
+
+BBUNIT_DEFINE_TEST(test_name)
+{
+	int *i;
+
+	i = malloc(sizeof(int));
+	BBUNIT_ASSERT_NOTNULL(i);
+	*i = 2;
+	BBUNIT_ASSERT_EQ((*i)*(*i), 4);
+
+	BBUNIT_ENDTEST;
+
+	free(i);
+}
+
+#endif /* ENABLE_UNIT_TEST */
+
+
+Running the unit test suite
+---------------------------
+
+To run the tests you can either directly run 'busybox unit' or use 'make test'
+to run both the unit tests (if compiled) and regular test suite.
diff --git a/include/libbb.h b/include/libbb.h
index 7a3610b..cede50c 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1941,6 +1941,141 @@ static ALWAYS_INLINE unsigned char bb_ascii_tolower(unsigned char a)
 #define isprint_asciionly(a) ((unsigned)((a) - 0x20) <= 0x7e - 0x20)
 
 
+/* Simple unit-testing framework */
+
+typedef void (*bbunit_testfunc)(void);
+
+struct bbunit_listelem {
+	struct bbunit_listelem* next;
+	const char* name;
+	bbunit_testfunc testfunc;
+};
+
+void bbunit_registertest(struct bbunit_listelem* test);
+void bbunit_settestfailed(void);
+
+#define BBUNIT_DEFINE_TEST(NAME) \
+	static void bbunit_##NAME##_test(void); \
+	static struct bbunit_listelem bbunit_##NAME##_elem = { \
+		.name = #NAME, \
+		.testfunc = bbunit_##NAME##_test, \
+	}; \
+	static void INIT_LAST bbunit_##NAME##_register(void) \
+	{ \
+		bbunit_registertest(&bbunit_##NAME##_elem); \
+	} \
+	static void bbunit_##NAME##_test(void)
+
+/*
+ * Both 'goto bbunit_end' and 'break' are here only to get rid
+ * of compiler warnings.
+ */
+#define BBUNIT_ENDTEST \
+	do { \
+		goto bbunit_end; \
+	bbunit_end: \
+		break; \
+	} while (0)
+
+#define BBUNIT_PRINTASSERTFAIL \
+	do { \
+		bb_error_msg( \
+			"[ERROR] Assertion failed in file %s, line %d", \
+			__FILE__, __LINE__); \
+	} while (0)
+
+#define BBUNIT_ASSERTION_FAILED \
+	do { \
+		bbunit_settestfailed(); \
+		goto bbunit_end; \
+	} while (0)
+
+/*
+ * Assertions.
+ * For now we only offer assertions which cause tests to fail
+ * immediately. In the future 'expects' might be added too -
+ * similar to those offered by the gtest framework.
+ */
+#define BBUNIT_ASSERT_EQ(EXPECTED, ACTUAL) \
+	do { \
+		if ((EXPECTED) != (ACTUAL)) { \
+			BBUNIT_PRINTASSERTFAIL; \
+			bb_error_msg("[ERROR] '%s' isn't equal to '%s'", \
+						#EXPECTED, #ACTUAL); \
+			BBUNIT_ASSERTION_FAILED; \
+		} \
+	} while (0)
+
+#define BBUNIT_ASSERT_NOTEQ(EXPECTED, ACTUAL) \
+	do { \
+		if ((EXPECTED) == (ACTUAL)) { \
+			BBUNIT_PRINTASSERTFAIL; \
+			bb_error_msg("[ERROR] '%s' is equal to '%s'", \
+						#EXPECTED, #ACTUAL); \
+			BBUNIT_ASSERTION_FAILED; \
+		} \
+	} while (0)
+
+#define BBUNIT_ASSERT_NOTNULL(PTR) \
+	do { \
+		if ((PTR) == NULL) { \
+			BBUNIT_PRINTASSERTFAIL; \
+			bb_error_msg("[ERROR] '%s' is NULL!", #PTR); \
+			BBUNIT_ASSERTION_FAILED; \
+		} \
+	} while (0)
+
+#define BBUNIT_ASSERT_NULL(PTR) \
+	do { \
+		if ((PTR) != NULL) { \
+			BBUNIT_PRINTASSERTFAIL; \
+			bb_error_msg("[ERROR] '%s' is not NULL!", #PTR); \
+			BBUNIT_ASSERTION_FAILED; \
+		} \
+	} while (0)
+
+#define BBUNIT_ASSERT_FALSE(STATEMENT) \
+	do { \
+		if ((STATEMENT)) { \
+			BBUNIT_PRINTASSERTFAIL; \
+			bb_error_msg("[ERROR] Statement '%s' evaluated to true!", \
+								#STATEMENT); \
+			BBUNIT_ASSERTION_FAILED; \
+		} \
+	} while (0)
+
+#define BBUNIT_ASSERT_TRUE(STATEMENT) \
+	do { \
+		if (!(STATEMENT)) { \
+			BBUNIT_PRINTASSERTFAIL; \
+			bb_error_msg("[ERROR] Statement '%s' evaluated to false!", \
+					#STATEMENT); \
+			BBUNIT_ASSERTION_FAILED; \
+		} \
+	} while (0)
+
+#define BBUNIT_ASSERT_STREQ(STR1, STR2) \
+	do { \
+		if (strcmp(STR1, STR2) != 0) { \
+			BBUNIT_PRINTASSERTFAIL; \
+			bb_error_msg("[ERROR] Strings '%s' and '%s' " \
+					"are not the same", STR1, STR2); \
+			BBUNIT_ASSERTION_FAILED; \
+		} \
+	} while (0)
+
+#define BBUNIT_ASSERT_STRNOTEQ(STR1, STR2) \
+	do { \
+		if (strcmp(STR1, STR2) == 0) { \
+			BBUNIT_PRINTASSERTFAIL; \
+			bb_error_msg("[ERROR] Strings '%s' and '%s' " \
+					"are the same, but were " \
+					"expected to differ", STR1, STR2); \
+			BBUNIT_ASSERTION_FAILED; \
+		} \
+	} while (0)
+
+
 POP_SAVED_FUNCTION_VISIBILITY
 
 #endif
diff --git a/include/platform.h b/include/platform.h
index 92f7755..413c222 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -76,6 +76,9 @@
 # define UNUSED_PARAM_RESULT
 #endif
 
+/* used by unit test machinery to run registration functions */
+#define INIT_LAST __attribute__ ((constructor(2000)))
+
 /* -fwhole-program makes all symbols local. The attribute externally_visible
  * forces a symbol global.  */
 #if __GNUC_PREREQ(4,1)
diff --git a/libbb/bbunit.c b/libbb/bbunit.c
new file mode 100644
index 0000000..2560144
--- /dev/null
+++ b/libbb/bbunit.c
@@ -0,0 +1,90 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * bbunit: Simple unit-testing framework for Busybox.
+ *
+ * Copyright (C) 2014 by Bartosz Golaszewski <bartekgola@gmail.com>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+//kbuild:lib-$(CONFIG_UNIT_TEST) += bbunit.o
+//applet:IF_UNIT_TEST(APPLET(unit, BB_DIR_USR_BIN, BB_SUID_DROP))
+
+//usage:#define unit_trivial_usage
+//usage:       ""
+//usage:#define unit_full_usage "\n\n"
+//usage:       "Run the unit-test suite"
+
+#include "libbb.h"
+
+#define WANT_TIMING 0
+
+static llist_t *tests = NULL;
+static unsigned tests_registered = 0;
+static int test_retval;
+
+void bbunit_registertest(struct bbunit_listelem *test)
+{
+	llist_add_to_end(&tests, test);
+	tests_registered++;
+}
+
+void bbunit_settestfailed(void)
+{
+	test_retval = -1;
+}
+
+#if WANT_TIMING
+static void timeval_diff(struct timeval* res,
+				const struct timeval* x,
+				const struct timeval* y)
+{
+	long udiff = x->tv_usec - y->tv_usec;
+
+	res->tv_sec = x->tv_sec - y->tv_sec - (udiff < 0);
+	res->tv_usec = (udiff >= 0 ? udiff : udiff + 1000000);
+}
+#endif
+
+int unit_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) MAIN_EXTERNALLY_VISIBLE;
+int unit_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
+{
+	unsigned tests_run = 0;
+	unsigned tests_failed = 0;
+#if WANT_TIMING
+	struct timeval begin;
+	struct timeval end;
+	struct timeval time_spent;
+	gettimeofday(&begin, NULL);
+#endif
+
+	bb_error_msg("Running %d test(s)...", tests_registered);
+	for (;;) {
+		struct bbunit_listelem* el = llist_pop(&tests);
+		if (!el)
+			break;
+		bb_error_msg("Case: [%s]", el->name);
+		test_retval = 0;
+		el->testfunc();
+		if (test_retval < 0) {
+			bb_error_msg("[ERROR] [%s]: TEST FAILED", el->name);
+			tests_failed++;
+		}
+		tests_run++;
+		el = el->next;
+	}
+
+#if WANT_TIMING
+	gettimeofday(&end, NULL);
+	timeval_diff(&time_spent, &end, &begin);
+	bb_error_msg("Elapsed time %u.%06u seconds"
+			(int)time_spent.tv_sec,
+			(int)time_spent.tv_usec);
+#endif
+	if (tests_failed > 0) {
+		bb_error_msg("[ERROR] %u test(s) FAILED", tests_failed);
+		return EXIT_FAILURE;
+	}
+	bb_error_msg("All tests passed");
+	return EXIT_SUCCESS;
+}
diff --git a/libbb/obscure.c b/libbb/obscure.c
index 24c4ac9..ad17d1f 100644
--- a/libbb/obscure.c
+++ b/libbb/obscure.c
@@ -182,3 +182,41 @@ int FAST_FUNC obscure(const char *old, const char *newval, const struct passwd *
 	}
 	return 0;
 }
+
+#if ENABLE_UNIT_TEST
+
+/* Test obscure_msg() instead of obscure() in order not to print anything. */
+
+static const struct passwd pw = {
+	.pw_name = (char *)"johndoe",
+	.pw_gecos = (char *)"John Doe",
+};
+
+BBUNIT_DEFINE_TEST(obscure_weak_pass)
+{
+	/* Empty password */
+	BBUNIT_ASSERT_NOTNULL(obscure_msg("Ad4#21?'S|", "", &pw));
+	/* Pure numbers */
+	BBUNIT_ASSERT_NOTNULL(obscure_msg("Ad4#21?'S|", "23577315", &pw));
+	/* Similar to pw_name */
+	BBUNIT_ASSERT_NOTNULL(obscure_msg("Ad4#21?'S|", "johndoe123%", &pw));
+	/* Similar to pw_gecos, reversed */
+	BBUNIT_ASSERT_NOTNULL(obscure_msg("Ad4#21?'S|", "eoD nhoJ^44@", &pw));
+	/* Similar to the old password */
+	BBUNIT_ASSERT_NOTNULL(obscure_msg("Ad4#21?'S|", "d4#21?'S", &pw));
+	/* adjacent letters */
+	BBUNIT_ASSERT_NOTNULL(obscure_msg("Ad4#21?'S|", "qwerty123", &pw));
+	/* Many similar chars */
+	BBUNIT_ASSERT_NOTNULL(obscure_msg("Ad4#21?'S|", "^33Daaaaaa1", &pw));
+
+	BBUNIT_ENDTEST;
+}
+
+BBUNIT_DEFINE_TEST(obscure_strong_pass)
+{
+	BBUNIT_ASSERT_NULL(obscure_msg("Rt4##2&:'|", "}(^#rrSX3S*22", &pw));
+
+	BBUNIT_ENDTEST;
+}
+
+#endif /* ENABLE_UNIT_TEST */
diff --git a/libbb/strrstr.c b/libbb/strrstr.c
index d8823fc..93d970a 100644
--- a/libbb/strrstr.c
+++ b/libbb/strrstr.c
@@ -7,13 +7,7 @@
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
-#ifdef __DO_STRRSTR_TEST
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#else
 #include "libbb.h"
-#endif
 
 /*
  * The strrstr() function finds the last occurrence of the substring needle
@@ -34,8 +28,9 @@ char* FAST_FUNC strrstr(const char *haystack, const char *needle)
 	}
 }
 
-#ifdef __DO_STRRSTR_TEST
-int main(int argc, char **argv)
+#if ENABLE_UNIT_TEST
+
+BBUNIT_DEFINE_TEST(strrstr)
 {
 	static const struct {
 		const char *h, *n;
@@ -59,13 +54,13 @@ int main(int argc, char **argv)
 	i = 0;
 	while (i < sizeof(test_array) / sizeof(test_array[0])) {
 		const char *r = strrstr(test_array[i].h, test_array[i].n);
-		printf("'%s' vs. '%s': '%s' - ", test_array[i].h, test_array[i].n, r);
 		if (r == NULL)
 			r = test_array[i].h - 1;
-		printf("%s\n", r == test_array[i].h + test_array[i].pos ? "PASSED" : "FAILED");
+		BBUNIT_ASSERT_EQ(r, test_array[i].h + test_array[i].pos);
 		i++;
 	}
 
-	return 0;
+	BBUNIT_ENDTEST;
 }
-#endif
+
+#endif /* ENABLE_UNIT_TEST */