Create Tests for MATLAB Source Code
MATLAB® Test™ enables you to interactively create tests for your scripts and functions in the Editor or Live Editor. The test file created for a script or function contains a test class to exercise that script or function. You can use this file as a starting point for writing your own tests.
This topic shows how to create a test for a simple function and then build on the generated test code.
Create Test for Function
In a file named quadraticSolver.m in your current folder, create the quadraticSolver function. The function takes as inputs the coefficients of a quadratic polynomial and returns the roots of that polynomial. To validate its inputs, the function uses an arguments block.
function r = quadraticSolver(a,b,c)% quadraticSolver returns solutions to the% quadratic equation a*x^2 + b*x + c = 0.arguments a {mustBeNumeric,mustBeNonzero} b {mustBeNumeric} c {mustBeNumeric}endr = sort([(-b + sqrt(b^2 - 4*a*c)) / (2*a); ... (-b - sqrt(b^2 - 4*a*c)) / (2*a)]);end
To create a test file that contains initial test code for the quadraticSolver function, right-click in the Editor and select Create Test.
This code provides the contents of the resulting test file. The generated test class:
Includes autogenerated inputs that satisfy the
argumentsblock in thequadraticSolverfunctionCalls the
quadraticSolverfunction to produce an outputUses the verifyEqual qualification method to test the produced output
% This is an autogenerated sample test for file quadraticSolver.mclassdef testquadraticSolver < matlab.unittest.TestCase methods (Test) function test_quadraticSolver(testCase) a = -7162.2732; b = -1564.7743; c = 8314.7105; % Specify the expected output(s) of % quadraticSolver expected_r = ; % Exercise the function quadraticSolver actual_r = quadraticSolver(a, b, c); testCase.verifyEqual(actual_r, expected_r); end endend
A test file created for your script or function serves only as a starting point. For example, you must at least specify the expected output in the test code generated for the quadraticSolver function before running the test.
Note
MATLAB Test attempts to generate input argument values only if your function uses an arguments block for input argument validation. If your function does not include an arguments block, then the test class does not include autogenerated data to represent the input arguments.
Build on Generated Test Code
Build on the test code generated for the quadraticSolver function by first completing the code of the generated Test method and then adding another Test method using the code insertion options on the toolstrip. For more information on how to interactively add elements to a test class, see Insert Test Code Using Editor.
Complete Generated Test Method
The generated test for the quadraticSolver function requires you to specify the expected output of the function. To complete the test and make it more readable, follow these steps:
Rename the test class as
SolverTestand theTestmethod assolution. Then, remove the comments you no longer need from the file and save the file asSolverTest.min your current folder.Specify the expected output of the function by calling the
rootsfunction with the autogenerated values.Because the
verifyEqualmethod tests floating-point vectors, specify a tolerance for comparison.
classdef SolverTest < matlab.unittest.TestCase methods (Test) function solution(testCase) a = -7162.2732; b = -1564.7743; c = 8314.7105; expected_r = sort(roots([a b c])); actual_r = quadraticSolver(a,b,c); testCase.verifyEqual(actual_r,expected_r,AbsTol=eps) end endend
Add Another Test Method
To test the quadraticSolver function against invalid inputs, add another Test method to the class by clicking 
in the Test section on the Editor tab.
Implement the added method by following these steps:
Rename the method as
nonnumericInput.Add code to the method to verify that the
quadraticSolverfunction throws an error when it is called with inputs1,'-3', and2.
Save the file. This code provides the contents of the SolverTest class.
classdef SolverTest < matlab.unittest.TestCase methods (Test) function solution(testCase) a = -7162.2732; b = -1564.7743; c = 8314.7105; expected_r = sort(roots([a b c])); actual_r = quadraticSolver(a,b,c); testCase.verifyEqual(actual_r,expected_r,AbsTol=eps) end function nonnumericInput(testCase) testCase.verifyError(@()quadraticSolver(1,'-3',2), ... "MATLAB:validators:mustBeNumeric") end endend
Run Tests in Test Class
You can run the tests in the SolverTest class interactively in the Editor or in the Test Browser app. For example, with the test class code visible in the Editor, go to the Editor tab and in the Run section, click 
. In this example, both the tests pass.
For more information on how to run tests and customize your test run interactively, see Run Tests in Editor and Run Tests Using Test Browser.
See Also
Functions
- verifyEqual
Classes
- matlab.unittest.TestCase
Related Topics
- Insert Test Code Using Editor
- Function Argument Validation
