Introduction to code quality

Transcription

1 Introduction to code quality Maarten Vandersteegen De Nayer, KU Leuven October 25, 2017

2 0 What? 2

3 0 Demo project 3

4 0 Demo project - hardware 4

5 0 Demo project - software 5

6 0 Content 6 1 Code versioning 2 Working in team 3 Test automation 4 Static and Dynamic code analysis 5 Continuous Integration

7 1 Outline 7 1 Code versioning 2 Working in team 3 Test automation 4 Static and Dynamic code analysis 5 Continuous Integration

8 1 Centralized version control 8

9 1 Centralized version control - examples 9

10 1 Distributed version control 10

11 1 Distributed version control - examples 11

12 1 Source code hosting in the cloud 12 git free public repos git, mercurial free private repos (5 user limit) git free private repos svn, git, mercurial svn, git, mercurial free private free public repos repos tfvc, git free private repos (5 user limit)

13 1 Demo project - version control 13

14 1 Demo project - workflow 14 # development branch g i t p u l l g i t add m y f i l e ; g i t commit... g i t add m y f i l e ; g i t commit g i t push # r e l e a s e to master g i t checkout master g i t p u l l g i t merge development g i t push g i t checkout development

15 2 Outline 15 1 Code versioning 2 Working in team 3 Test automation 4 Static and Dynamic code analysis 5 Continuous Integration

16 2 Task management 16

17 2 Task management - github 17

18 2 Documentation 18 API documentation (.h files) 1 /* 2 * Parse HTTP response 3 * in: HTTP response string from server 4 * regex_passed: Regex that matches in when the build has passed 5 * regex_running: Regex that matches in when the build is running 6 * regex_failed: Regex that matches in when the build has failed 7 * state: The resulting build status 8 * return: 0 on success, -1 on failure 9 */ 10 int response_parser_get_result(const char *in, const char *regex_passed, 11 const char *regex_running, 12 const char *regex_failed, 13 enum BuildState *state); Use wiki for functional documentation: tutorials/howtos use case examples

19 2 Code review - github 19

20 2 Atlassian toolbox 20

21 3 Outline 21 1 Code versioning 2 Working in team 3 Test automation 4 Static and Dynamic code analysis 5 Continuous Integration

22 3 Layers of testing 22

23 3 Layers of testing 23

24 3 Flow of a unit test 24 fixating the test conditions to a known state One or more actions that operate on the SUT (system under test) One or more conditions that need to be true undo setup

25 3 Example in pseudo code 25 1 /* setup */ 2 login_manager_init(); 3 login_manager_set_expected_passphrase("3xp3ctedpa22"); 4 5 /* act */ 6 login_manager_login("3xp3ctedpa22"); 7 8 /* assert */ 9 assert(login_manager_success() == OK); /* teardown */ 12 login_manager_deinit(); 13 Keep it short Avoid conditions (if/else/switch)

26 3 Basic unit test in C using cmocka 26 1 #include <stdarg.h> 2 #include <stddef.h> 3 #include <setjmp.h> 4 #include <cmocka.h> /* yes, all these includes are needed */ 5 6 void test_example(void **state) 7 { 8 assert_true(1); 9 } int main(void) 12 { 13 const struct CMUnitTest tests[] = { 14 cmocka_unit_test(test_example), 15 }; 16 return cmocka_run_group_tests(tests, NULL, NULL); 17 } 18 gcc -Wall test.c -o test -lcmocka &&./test [==========] Running 1 test(s). [ RUN ] test_example [ OK ] test_example [==========] 1 test(s) run. [ PASSED ] 1 test(s).

27 3 Unit test example 27 response_parser.h 1 int response_parser_get_result(const char *in, const char *regex_passed, 2 const char *regex_running, 3 const char *regex_failed, 4 enum BuildState *state); 5 test.c 1 void test_response_parser_build_passed(void **state) 2 { 3 int res; 4 enum BuildState build_state; 5 char *response = "{\"key\":\"value\", \"state\":\"passed\"}"; 6 7 /* act */ 8 res = response_parser_get_result(response, "\"state\":\"passed\"", 9 "\"state\":\"started created\", 10 "\"state\":\"failed\"", 11 &build_state); /* assert */ 14 assert_int_equal(res, 0); 15 assert_int_equal(build_state, BUILD_STATE_PASSED); 16 } 17

28 3 Extended unit test example 28

29 3 Extended unit test example 29

30 3 What is a mock? 30

31 3 Extended unit test example 31 lamp_control.c (SUT) 1 void lamp_control_set_state(enum LampState *lamp_state, enum BuildState build_state) 2 { 3 build_state_to_lamp_state(lamp_state, build_state); 4 lamp_io_set_state(*lamp_state); 5 } 6 7 lamp_io.c (need to create a mock for this) 1 void lamp_io_set_state(enum LampState lamp_state) 2 { 3 switch (lamp_state) { 4 case LAMP_STATE_OFF : 5 digitalwrite(lamp_io_red_pin, LOW); 6 digitalwrite(lamp_io_green_pin, LOW); 7 break; 8 case LAMP_STATE_GREEN : 9 digitalwrite(lamp_io_red_pin, LOW); 10 digitalwrite(lamp_io_green_pin, HIGH); 11 break; 12 case LAMP_STATE_RED : }; 15 } 16

32 3 Extended unit test example 32 test.c 1 /* mock */ 2 void lamp_io_set_state(enum LampState lamp_state) 3 { 4 check_expected(lamp_state); 5 } 6 7 /* test */ 8 void test_set_state_build_failed(void **state) 9 { 10 enum LampState current_lamp_state; 11 /* setup */ 12 current_lamp_state = LAMP_STATE_OFF; 13 expect_value(lamp_io_set_state, lamp_state, LAMP_STATE_RED); 14 /* act */ 15 lamp_control_set_state(&current_lamp_state, BUILD_STATE_FAILED); 16 /* assert */ 17 assert_int_equal(current_lamp_state, LAMP_STATE_RED); 18 } 19 NOTE: cmocka implementation

33 3 Layers of testing 33

34 3 Integration/system testing 34

35 3 Integration/system testing 35

36 3 Layers of testing 36

37 3 Acceptance testing 37

38 3 Acceptance testing 38 + real end-to-end slow running tests high maintanance

39 4 Outline 39 1 Code versioning 2 Working in team 3 Test automation 4 Static and Dynamic code analysis 5 Continuous Integration

40 4 Static code analysis 40 + Finding potential bugs/security issues + Detecting code smells + Guarantees 100% code coverage + Validating coding standards

41 4 Static code analysis aspects 41 abstract interpretation cyclomatic complexity coding standards duplicate code compiler warnings

42 4 Static code analysis process 42

43 4 Static code analysis tools 43 free/paid C/C++, C#, Java, JS, Python, Ruby open source C/C++, Objective-C open source C/C++, C#, Java, JS, PHP, Python,... paid C/C++, C#, Java, JS, Go, Python,... paid C/C++, Java,.NET open source C/C++

44 4 Abstract interpretation - demo project 44

45 4 Dynamic code analysis 45 + Measuring test coverage + Finding complex issues not detectable by static analysis + Gives insight for improving efficiency (speed, memory) No 100% coverage ensured Tests run (deadly) slow

46 4 Dynamic code analysis aspects 46 Code coverage Issue analysis Profiling

47 4 Dynamic code analysis process 47

48 4 Code coverage tools - C/C++ 48 gcov/lcov open source line/branch coverage llvm-cov open source line/region coverage paid decision/condition coverage paid all types of coverage

49 4 Code coverage gcov/lcov - demo project 49 1 CFLAGS += --coverage 2 LDFLAGS += --coverage 3 1 lcov... 2 genhtml... 3 Makefile Report generation

50 4 Code coverage - demo project 50

51 4 Issue analysis & profiling tools - C/C++ 51 open source Mem leak, threading, heap/cache profiling Sanitizers (also in gcc!) open source Mem leak, addr issues, threading, non init mem Insure++ paid Mem, threading, file I/O, network,...

52 4 Address sanitizer - demo project 52 Instrumentation flags 1 CFLAGS += -fno-omit-frame-pointer -fsanitize=address 2 LDFLAGS += -fno-omit-frame-pointer -fsanitize=address 3 On runtime error 1 ================================================================= 2 ==6305==ERROR: AddressSanitizer: stack-buffer-overflow on... 3 READ of size 18 at 0x7ffe1ac4ab51 thread T0 4 #0 0x7f3da492f1e #1 0x7f3da492fbcc in vfprintf... 6 #2 0x7f3da492fcf9 in fprintf... 7 #3 0x40262a in regex_report_and_cleanup /home/maarten/code/rpi-ci-lamp/ lib/response_parser.c:15 8 #4 0x4027d8 in perform_regex /home/maarten/code/rpi-ci-lamp/lib/ response_parser.c:

53 5 Outline 53 1 Code versioning 2 Working in team 3 Test automation 4 Static and Dynamic code analysis 5 Continuous Integration

54 5 Getting it all together 54

55 5 CI pipeline in practice 55

56 5 CI tools 56 free NXP, Netflix, Facebook, Ebay, NASA free/paid Apple, Stackoverflow, Ebay, Cochlear free/paid, hosted Facebook, Twitter free trial... free/paid, hosted EAVISE,... paid Materialise

57 5 CI pipeline demo project 57

58 5 Travis CI - how does it work? 58

59 5 Travis CI - how does it work? 59.travis.yml 1 dist: trusty 2 language: c 3 4 addons: 5 apt: 6 packages: 7 - libcurl4-openssl-dev 8 - libconfig-dev 9 install: 10 - wget tar -xvf cmocka tar.xz script: 15 - make DEBUG=1 NOWIRINGPI=1 test 16 -./test/run_unit_tests.sh after_success: 19 - gcov -bclp lib/*.c bin/*.c 20 - bash <(curl -s 21

60 5 Build status notifications 60 /rss feed on failure build lamp build result badges

61 5 Full demo 61

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