Run BioCro module test cases

Modules can be tested using test cases, which are sets of known outputs that correspond to particular inputs. The functions here provide ways to create test cases and test modules.

test_module runs one test case for a module, returning an error message if its output does not match the expected value.

case helps define test cases for module testing by combining the required elements into a list with the correct names as required by test_module.

cases_from_csv helps define test cases for module testing by creating a list of test cases from a csv file.

Usage

test_module(module_name, case_to_test)

  case(inputs, expected_outputs, description)

  cases_from_csv(module_name, directory)

Arguments

module_name

A string specifying one BioCro module, formatted like library_name:local_module_name, where library_name is the name of a library that contains a module with local name local_module_name; such fully-qualified module names can be formed manually or with module_paste.

case_to_test

A list with three named elements that describe a module test case:

• inputs: A list of module inputs, i.e., a list of named numeric elements corresponding to the module's input quantities.

• expected_outputs: A list of expected module outputs, i.e., a list of named numeric elements corresponding to the expected values of the module's output quantities.

• description: A string describing the test case, e.g. "temp below tbase". The description should be succinct and not contain any newline characters.

inputs

See the corresponding entry in test_case above.

expected_outputs

See the corresponding entry in test_case above.

description

See the corresponding entry in test_case above.

directory

The directory where module test case files are stored, e.g. file.path('tests', 'module_test_cases')

Details

The test_module function forms the basis for the BioCro module testing system. (See module_testing for more information.) The functions case and cases_from_csv are complementary to test_module because they help to pass suitably-formatted test cases to test_module.

Value

test_module

If the test passes, an empty string; otherwise, an informative message about what went wrong.

case

A list with three named elements (inputs, expected_outputs, and description) formed from the input arguments.

cases_from_csv

A list of test cases created by the case function that are each suitable for passing to the test_module function.

See also

• modules

• module_case_files

• module_paste

• module_testing

• test_module_library

Examples

# Example 1: Defining an individual test case for the 'BioCro' module library's
# 'thermal_time_linear' module and running the test. This test will pass, so the
# return value will be an empty string: `character(0)`
test_module(
  'BioCro:thermal_time_linear',
  case(
    list(time = 101, sowing_time = 100, tbase = 20, temp = 44),
    list(TTc = 1.0),
    'temp above tbase'
  )
)
#> character(0)

# Example 2: Defining an individual test case for the 'BioCro' module library's
# 'thermal_time_linear' module and running the test. This test will fail, so the
# return value will be a message indicating the failure.
test_module(
  'BioCro:thermal_time_linear',
  case(
    list(time = 101, sowing_time = 100, tbase = 20, temp = 44),
    list(TTc = 2.0),
    'temp above tbase'
  )
)
#> [1] "Module `BioCro:thermal_time_linear` test case `temp above tbase`: calculated outputs do not match expected outputs"

# Example 3: Loading a set of test cases from a file and running one of them.
# Note: here we use the `initialize_csv` function first to ensure that there is
# a properly defined test file in a temporary directory.

td <- tempdir()

module_name <- 'BioCro:thermal_time_linear'
initialize_csv(module_name, td)
#> [1] "Did not initialize case file because `/tmp/Rtmpa12Fsi/BioCro_thermal_time_linear.csv` already exists"
cases <- cases_from_csv(module_name, td)
test_module(module_name, cases[[1]])
#> character(0)