I have some issues with using addTeardown in the unit testing framework.
The following examples help me to understand addTeardown, I hope it helps the reader of this post.
In software testing, a teardown fixture is a routine or code block that is executed after a test has finished running. It is typically used to clean up the resources that were allocated or created during the test, such as closing database connections, deleting temporary files or directories, or releasing memory.
The teardown fixture is the counterpart of the setup fixture, which is a routine or code block that is executed before a test is run. The setup fixture is used to initialize the resources required for the test.
Together, the setup and teardown fixtures form a test fixture. A test fixture is a set of resources and conditions that are used to prepare a system for testing and to clean up after testing is complete. It helps ensure that each test is run in a consistent and isolated environment, which is important for achieving reliable and repeatable results.
Using a teardown fixture is important because it ensures that resources are properly released, which can prevent issues such as memory leaks or database locks. It also helps to ensure that subsequent tests are not affected by any changes made by earlier tests, which can lead to unpredictable behavior and false positives or false negatives in test results.
In MATLAB, testCase.addTeardown is a method that allows you to register a function to be called after a test has completed.
testCase.addTeardown(@profile, ‘off’)
This tells MATLAB to turn off profiling after the test has completed, so that profiling does not affect subsequent tests or code execution.
testcase.addTeardown(@() close_system(testcase.TestModel, 0))
The close_system function is a built-in MATLAB function that closes a Simulink model or subsystem. The first argument (testcase.TestModel) is the Simulink model or subsystem that was opened and used for testing, while the second argument (0) specifies that the model should be closed without saving any changes.
By registering this function as a teardown function using testCase.addTeardown, the Simulink model used for testing will be automatically closed after the test has completed, even if the test fails. This ensures that subsequent tests are not affected by any changes made to the model during the test, and that the model is in a clean state for the next test.
fid = fopen(imname, ‘r’); testCase.addTeardown(@()fclose(fid))
In MATLAB,
is a function that opens a file and returns a file identifier, which can be used to read from or write to the file. The first line of code,
, opens a file specified by the variable
in read-only mode (
) and assigns the file identifier to the variable
.
The second line of code,
, registers a teardown function with the
object. The teardown function is an anonymous function that calls the
function with the file identifier
as an input argument. This function is executed automatically by MATLAB after each test case is run, and it closes the file that was opened in the first line of code.
The purpose of this code is to ensure that the file that was opened for testing is always closed, even if the test fails or throws an error. This is important because leaving a file open can cause issues with file locks or file access permissions, which can affect subsequent tests or code execution. By using
, this code ensures that the file is always closed, even if an error occurs during the test.
% ModelParams
evalin(‘base’,’t = 0:0.01:10;’);
evalin(‘base’,’K = [tvmat(cot(t),t) 1; 2 3];’);
evalin(‘base’,’inMAT = [tvmat(sin(t),t) 1 0;0 2 3];’);
% Clear base workspace
evalinBase = @(command) evalin(‘base’,command);
testCase.addTeardown(evalinBase,’clear t K inMAT’);
This code defines three variables (
,
, and
) in the base workspace of MATLAB. The variables are defined using the
function, which allows you to execute a string containing MATLAB code in a specified workspace.
The first line of code,
, creates a variable
that is a vector of values from 0 to 10 in steps of 0.01.
The second line of code,
, creates a 2×2 matrix
with elements that depend on the values of
. The
function is assumed to be defined elsewhere in the code.
The third line of code,
, creates a 2×3 matrix
with elements that also depend on the values of
.
The fourth line of code,
, adds a teardown function to the
object. The teardown function uses an anonymous function that calls
with the base workspace and the string
as input arguments. This function is executed automatically by MATLAB after each test case is run, and it clears the variables
,
, and
from the base workspace.
The purpose of this code is to define some variables in the base workspace of MATLAB for use in a test, and then ensure that those variables are always cleared from the workspace, even if the test fails or throws an error. This is important because leaving variables in the workspace can affect subsequent tests or code execution, and clearing them after the test ensures that the workspace is in a clean state for the next test. By using
, this code ensures that the variables are always cleared, even if an error occurs during the test.
