Test fixtures: Reusing test data configuration between tests

class: center, middle, inverse, title-slide

# Test fixtures: Reusing test data configuration between tests
### Bai Li National Stock Assessment Program Modeling Team Contractor with ECS in support of NOAA Fisheries Office of Science and Technology <code>bai.li@noaa.gov</code>
### Nov 17, 2022 FIMS C++ office hour Updated on 2022-11-17

---

layout: true

.footnote[U.S. Department of Commerce | National Oceanic and Atmospheric Administration | National Marine Fisheries Service]

---
# Test fixture definition

- An object the test runs against*1*
 - can be a regular dependency: an argument to be passed, data in the database, or a file on the hard disk
 - remain in a known and fixed state to produce the same results before executing tests
 
- Help set up **custom initialization work** for multiple tests*2*
 - preconditions 
 - data
 - cleanup procedures
 
.footnote[
[1]Khorikov V. 2020. Unit testing: principles, practices, and patterns. Shelter Island, NY: Manning. 
[2]GoogleTest Users' guide: [http://google.github.io/googletest/primer.html#same-data-multiple-tests](http://google.github.io/googletest/primer.html#same-data-multiple-tests) 
]

---
**Use test fixture when you find you are repeating yourself**

```c++
TEST(PopulationModuleTest, CalculateMortality_works)
{
 fims::Population<double> population;
 population.nyears = 30;
 population.nages = 12;
 int year = 2;
 int age = 7; 
 int index_ya = year * population.nages + age;
 
 population.CalculateMortality(index_ya, year, age);
 
 EXPECT_EQ(population.mortality_F[index_ya], 3.5);
}
```

```c++
TEST(PopulationModuleTest, CalculateNumbersAA_works)
{
 fims::Population<double> population;
 population.nyears = 30;
 population.nages = 12;
 int year = 4;
 int age = 6; 
 int index_ya = year * population.nages + age;
 int index_ya2 = (year - 1) * population.nages + age - 1;
 
 population.CalculateNumbersAA(index_ya, index_ya2);
 
 EXPECT_EQ(population.numbers_at_age[index_ya], 1234); 
}
```
---
# Google Test template
.pull-left[
- Simple test

```c++
TEST(TestSuiteName, TestName1){
  ...test body...
}

TEST(TestSuiteName, TestName2){
  ...test body...
}
```
]

.pull-right[
- Fixture test

```c++
TEST_F(TestFixtureName, TestName1){
  ...test body...
}

TEST_F(TestFixtureName, TestName2){
 ...test body...
}
```
]
---
# Steps to create a Google Test fixture class*1*
- Derive a class from `::testing::Test`
- Start its body with `protected:`
- Declare any objects you plan to use inside the class
- Write a default constructor or `SetUp()` function to prepare the objects
- Write a destructor or `TearDown()` function to release any resources that are allocated in `SetUp()`. 
- Define subroutines for your tests to share
 
```c++
class TestFixtureName : public ::testing::Test{
 protected:
 void SetUp() override{
 ...SetUp body...
 }
 
 void TearDown() override {
 ...TearDown body...
 }
 
 ...Other subroutines...
}
```
.footnote[
[1]GoogleTest Users' guide: [http://google.github.io/googletest/primer.html#same-data-multiple-tests](http://google.github.io/googletest/primer.html#same-data-multiple-tests) 
]
---
# FIMS test fixture files (WIP)
- [FIMS/tests/gtest/test_population_test_fixture.hpp](https://github.com/NOAA-FIMS/FIMS/blob/9469d42eeb6193a149762bcbdb462c3d5c45c148/tests/gtest/test_population_test_fixture.hpp)

- [FIMS/tests/gtest/test_population_dynamics_population_initialize_prepare.cpp](https://github.com/NOAA-FIMS/FIMS/blob/9469d42eeb6193a149762bcbdb462c3d5c45c148/tests/gtest/test_population_dynamics_population_initialize_prepare.cpp)

- [FIMS/tests/gtest/test_population_NumbersAtAge.cpp](https://github.com/NOAA-FIMS/FIMS/blob/9469d42eeb6193a149762bcbdb462c3d5c45c148/tests/gtest/test_population_NumbersAtAge.cpp)

- [FIMS/tests/gtest/test_population_Li.cpp](https://github.com/NOAA-FIMS/FIMS/blob/9469d42eeb6193a149762bcbdb462c3d5c45c148/tests/gtest/test_population_Li.cpp)

- [FIMS/tests/gtest/test_population_MaturityAtAge.cpp](https://github.com/NOAA-FIMS/FIMS/blob/9469d42eeb6193a149762bcbdb462c3d5c45c148/tests/gtest/test_population_MaturityAtAge.cpp)
---
# FIMS test files diagram
<div id="htmlwidget-2343ed7ecef39e4b439e" style="width:100%;height:504px;" class="DiagrammeR html-widget"></div>
<script type="application/json" data-for="htmlwidget-2343ed7ecef39e4b439e">{"x":{"diagram":"\ngraph LR\n 1[<center>test_population_test_fixture.hpp<\/b><\/center>];\n 2[PopulationInitializeTestFixture];\n 3[PopulationPrepareTestFixture];\n 2-1[<center>test_population_dynamics_population_initialize_prepare.cpp<\/b><\/center> test: input_data_are_specified];\n 2-2[<center>test_population_dynamics_population_initialize_prepare.cpp<\/b><\/center> test: Initialize_works];\n 3-1[<center>test_population_dynamics_population_initialize_prepare.cpp<\/b><\/center> test: Prepare_works];\n 3-2[<center>test_population_NumbersAtAge.cpp<\/b><\/center> test: CalculateNumbersAA_works];\n 3-3[<center>test_population_Li.cpp<\/b><\/center> test: CalculateMortality_works];\n 3-4[<center>test_population_MaturityAtAge.cpp<\/b><\/center> test: CalculateMaturityAA_works];\n 1-->2\n 1-->3\n 2-->2-1\n 2-->2-2\n 3-->3-1\n 3-->3-2\n 3-->3-3\n 3-->3-4\n"},"evals":[],"jsHooks":[]}</script>
---
# PopulationInitializeTestFixture
- `PopulationInitializeTestFixture` derives from the fixture base class `::testing::Test`

- Members of the test fixture class (e.g., population object, `id_g`, `nyears`, `nseasons`, `nages`, and `nfleets` will be set

- Population `id_g`, `nyears`, `nseasons`, `nages`, `nfleets`, and `fleet` from the `SetUp()` will be called **before** all tests using the fixture

- `TearDown()` will be called **after** all tests using the fixture are run

---
# PopulationPrepareTestFixture
  - `population.Initialize()` and `population.Prepare()` functions will be called **before** all tests using the fixture
  
  - `population.log_naa`, `population.log_M`, `population.log_Fmort` pseudo-random numbers will be generated using `std::default_random_engine` class **before** all tests using the fixture
  
  - Make shared pointers to `selectivity`, `fleet`, and `maturity` to set up `population.fleets` and `population.maturity`
---
# Thanks!

bai.li@noaa.gov