An introduction to Google test framework

An Introduction to Google Test Framework

Abner HuangJuly. 2015

Test!? We do it every day

void Test__calc_isect() {

int x1, y1, x2, y2;

int x3, y3, x4, y4;

int x, y;

x1 = 0; y1 = INT_MIN; x2 = 2; y2 = INT_MAX;

x3 = 20; y3 = INT_MAX; x4 = 22; y4 = INT_MIN;

calc_isect(&x, &y, x1, y1, x2, y2, x3, y3, x4, y4, 0);

assert(x == 11);

assert(y == INT_MAX);

}

void main(void)

{

Test__calc_isect1();



Test__calc_isect();




}

> ./test.out

test.cpp:100:Test__calc_isect(): Assertion `x == 11' failed.

void Test__calc_isect() {

int x1, y1, x2, y2;

int x3, y3, x4, y4;

int x, y;




if ((x != 11) || (y != INT_MAX))

{

printf(“Oops! (%d,%d) != (%d,%d)\n”,x,y,11,INT_MAX);

assert(0);

}

printf(“PASS\n”);

}

> ./test.out

PASS

PASS

PASSOops! (10,2147483647) != (11,2147483647)

test.cpp:100:Test__calc_isect(): Assertion `0' failed.

Any complains?

No convenient controls

Run in batch mode

Does gtest help?

No control of test suite and test cases

./your_test.out --help

● Selecting Tests

● Repeating/Shuffling the Tests

● Generating an XML Report

● Turning Assertion Failures into Break-Points○ --gtest_break_on_failure

● Disabling Catching Test-Thrown Exceptions○ --gtest_catch_exceptions=0

> libpl_test --gtest_list_tests

CHK_ENCLOSE.

PlEnclose_SimpleInput

MAKE_BD.

MakeBd_LineTouchDirty

OSIZE_HDR.

OversizeHdr_BadOversizAmount

OversizeHdr_NULLInput

OversizeHdr_SimpleInput

OversizeHdr_OversizeOrthoHdr

OversizeHdr_OversizeNonOrthoHdr

OversizeOrthoHdr_OversizeOrthoHdr

BreakUpAngleHdr_DisconnectedInput

BreakUpAngleHdr_AngleBigInput

https://www.flickr.com/photos/marckjerland/4285433177 On Flickr, marc kjerland's Mathematician's toolkit

https://www.flickr.com/photos/marckjerland/4285433177

https://www.flickr.com/photos/marckjerland/4285433177

● Fatal and non-fatal assertions○ EXPECT_EQ(x, 10);EXPECT_FLOAT_EQ(x,10.0)

○ ASSERT_EQ(x, 10);ASSERT_DOUBLE_EQ(x,10.0)

● Easy assertions informative messages:assert(x == 10);

EXPECT_EQ(x, 10) << “vector (” << old_x <<

”,” << old_y << ”) moved to (” << x << ”,” <<

y << ”)\n”;

> ./test.out

[ RUN ] MYTEST.TestFoo

test.cpp:37: Failure

Value of: x

Actual: 11

Expected: 10

vector (10, 77) move to (11, 77)

[ FAILED ] MYTEST.TestFoo (0 ms)

DEATH TEST calc_isect(int *x, int *y, int x1, int y1, int x2, int y2,

int x3, int y3, int x4, int y4, int tolerance)

{

if (x==NULL || y==NULL)

{

cerr << “Input is invalid.\n”;

exit(1);

}

… …}

TEST(GEODeathTest, CalcIsect) {

ASSERT_DEATH(CalcIsect(NULL, NULL, 0,0,0,0,0,0,0,0,0),

".*invalid");

}

Adding Traces to Assertions

void Sub1(int n) {

EXPECT_EQ(1, Bar(n));

EXPECT_EQ(2, Bar(n + 1));

}

TEST(FooTest, Bar) {

{

SCOPED_TRACE("A");

Sub1(1);

}

Sub1(9);

}

path/to/foo_test.cc:11: Failure

Value of: Bar(n)

Expected: 1

Actual: 2

Trace:

path/to/foo_test.cc:17: A

path/to/foo_test.cc:12: Failure

Value of: Bar(n + 1)

Expected: 2

XML outputs<testsuites name="AllTests" tests="3" failures="

1" errors="0" time="35" ...>

<testsuite name="test_case_name" tests="2"

failures="1" errors="0" time="15"...>

<testcase name="test_name" status="run"

time="7"...>

<failure message="..."/>

<failure message="..."/>

</testcase>

</testsuite>

</testsuites>

Prepare your test case• test.cpp contains main() in test directory

#include "_test_util.h"

static void

infrastructure_init(void)

{

vmemUseMalloc(1);

vmemInit_m();

vmemSetIncrementValue(VMEM_MEGABYTE_MINUS);

hoVMsetDefaultPoolLockingState(0);

vth_init();

}

int main(int argc, char **argv) {

infrastructure_init(); // Write a function like this to initialize vmem, threading etc.

::testing::InitGoogleTest(&argc, argv);

int result = RUN_ALL_TESTS(); Initialize gtest and runs all tests.

return result;

}

SetUp()

TEST/TEST_F/TEST_PTearDown()

Test types of Gtest

• TEST()• TEST_F() -- Fixture

• TEST_P() -- Value-parameterized fixture– Range()– Values()– ValuesIn()– Bool()– Combine()

TEST(GEO, CalcIsect) {

int x1, y1, x2, y2;

int x3, y3, x4, y4;

int x, y;




assert(x == 11);


}

Test Fixtures

• Sometimes you want to run several tests on similar data structures (same setup before running test).

• In a fixture you define common setup/tear-down for multiple tests

• Reduces amount of test code by avoiding repetition

class GEO : public ::testing::Test {

protected:

virtual void SetUp() {}

void ZapMemoryPool() {}

virtual void TearDown() {}

int x1, y1, x2, y2, x3, y3, x4, y4, x, y;

};

TEST_F(GEO, CalcIsect) {




assert(x == 11);


}

TEST_P() -- Value-parameterized fixture

● generator based tests.

Range(begin, end[, step])

Yields values {begin, begin+step, begin+step+step, ...}. The values do not include end. step defaults to 1.

Values(v1, v2, ..., vN) Yields values {v1, v2, ..., vN}.

ValuesIn(container) and ValuesIn(begin, end)

Yields values from a C-style array, an STL-style container, or an iterator range [begin, end). container, begin, and end can be expressions whose values are determined at run time.

Bool() Yields sequence {false, true}.

Combine(g1, g2, ..., gN)

Yields all combinations (the Cartesian product for the math savvy) of the values generated by the N generators. This is only available if your system provides the <tr1/tuple> header.

class GEO : public ::testing::TestWithParam<int> {

protected:

virtual void SetUp() {}

void ZapMemoryPool() {}

virtual void TearDown() {}

int x1, y1, x2, y2, x3, y3, x4, y4, x, y;

};

INSTANTIATE_TEST_CASE_P(AUTO_GEN_OH, GEO, ::testing::Range(1,12,1));

TEST_P(GEO, CalcIsect) {

double angle = PI/180 * 15 * GetParam();

x1 = -100; y1 = 0; x2 = 100; y2 = 0;

x3 = -50; y3 = 0; x4 = 50; y4 = 0;

rotate(&x3, &y4, angle);

rotate(&x4, &y4, angle);


assert(x == 0 && y == 0);

}

[----------] 16 tests from AUTO_GEN_OH/GEO

[ RUN ] AUTO_GEN_OH/GEO.CalcIsect/1

[ OK ] AUTO_GEN_OH/GEO.CalcIsect/1 (0 ms)





















[----------] 11 tests from AUTO_GEN_OH/GEO (0 ms total)

Organization of Tests

TEST(GEO, CalcIsect)test case test

Test Suite

Flow of Running Tests

SetUp()

TEST/TEST_F/TEST_PTearDown()

Environment::SetUp()

SetUpTestCase()

Environment::TearDown()

TearDownTestCase()

How to install gtest

Easy Install> wget http://googletest.googlecode.com/files/gtest-1.7.0.zip

> unzip gtest-1.7.0.zip

> cd gtest-1.7.0

> ./configure

> make

> cp -a include/gtest /usr/include

> sudo cp -a lib/.libs/* /usr/lib/

http://googletest.googlecode.com/files/gtest-1.7.0.zip

How to use google test

• You must check out gtest to use unit test feature. We do not have the executable of gtest.

• E.g.– /path/to/foo/

– build

– arch

– src

– exec

– gtest

– include

– lib

How to use google test (II)

• E.g./path/to/foo/

– exec

– gtest

– include

– lib

– bar <<< Library under test, contains production code

– published

– test <<< Directory contains test code

test> make

Some points to keep in mind

• gtest is useful for testing primitive functions in libraries• Unit testing does not replace regression testing• With gtest:

– You do not modify production code. – You add test code that calls library functions.– You check-in test code to repository

• Production code is not compiled/linked with gtest• Using gtest creates a test binary, not icv binary

Coding Style and Rules

• Don’t mix TEST(), TEST_F(), TEST_P()• Don’t use global variables, use test fixture to instead• Gtest does not reuse the same test fixture object across

multiple tests• Spell SetUp() correctly.• Gtest use fork() to do death test, do not try not to free

memory in a death test.• You can derive new class from your own class.

Coding Style and Rules

• Use Camel Case style to name test cases and suite– E.g., TEST(Time, Flies_Like_An_Arrow) { ... }

and TEST(Time_Flies, Like_An_Arrow) { … }will have the same name Time_Files_Like_An_Arrow_Test

• Current Naming Rule– Test suite name is all uppercase– Test case name is Camel Case style with underscore.

– E.g., TEST_F(SPACING_UTIL__PNT_EDGE, WhichHalfRes_SamePoints)

Key Features & Characters Boost Test Google Test UnitTest++

Free (Open Source) software Yes Yes Yes

Simple to use Yes(5 out of 5)

Yes(5 out of 5)

Yes(4 out of 5)

Test cases grouping & organization Good Good Normal

Test case template support Yes Yes Yes

Test fixture (i.e. fixed state used as a baseline for running test) support

Yes Yes Yes

Global test fixture Yes Yes No

Handle C++ exceptions Yes Yes Yes

Different types of assertions support Yes Yes No

Fatal and non-fatal assertions Yes Yes No

Support Regular Expression when matching function output

Yes Yes No

Output in XML format Yes Yes No

Key Features & Characters Boost Test Google Test UnitTest++

Support Mock object (objects can simulate the behavior of complex objects)

No Yes(work seamlessly with

Google Mock)

No

Extend features with event mechanism

No Yes No

Run tests on distributed machines No Yes No

Thread safety when running tests No Yes No

Run subset of all defined test cases Yes(only support

filtering by test name)

Yes(support multiple

filtering conditions)

No

• Karl Chen, C++ Unit Testing Frameworks Evaluation

http://swe/sde/googletest/Documents/unit_test_frameworks_evaluation.pptx

Thank you

An introduction to Google test framework

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