Test Units Overview

Introduction

STRIDE enables testing of C++ code through the use of xUnit-style test classes. Test classes can be written by engineers, captured using an SCL pragma, and executed from the host. STRIDE facilitates the execution of some or all of the test classes by automatically creating entry points for the execution of test classes on the target.

Using C++ test classes

Prerequisites

see Test Utility Prerequisites.

How to get started

The required steps to get started with writing C++ test classes are as follows:

1. Create a new Studio workspace (or open an existing one).
2. Set the workspace to compile in C++ mode (In Studio, choose Tools->Settings->Compile as Cpp).
3. Add %STRIDE_DIR%\inc\srtest.h to the Source Files folder of your workspace.
4. Set %STRIDE_DIR%\scripts\frameworks\Common\scripts\PreprocessTestClasses.pl to your Workspace's Pre-Compile Script property (click Workspace and Pre-Compile Script appears in the Properties).

   This script is a preprocessor and code generator. It searches all source files in the current workspace and looks for test classes that have been captured via the scl_test_class pragma. It then generates C-linkage wrapper functions that instantiate and execute each test class. By default, this generated source file has a name of the form <workspace_name>_run.cpp and will be located in the workspace directory. If you need to customize the name and/or location of this generated file, simply create your own version of the preprocessor script and set the outFile property of the STRIDE.testclass_codegen object prior to calling the generate method. Note: This preprocessing script must always preceed the compilation step.

5. Create a script to generate the Intercept Module(IM) after the compilation step.

   For the simple STUB generation required for C++ test class execution, you can use the following code (perl syntax)

  use strict;
  use Win32::OLE qw(in);
  Win32::OLE->Option(Warn => 3);
  my $intercept = $main::studio->Workspace->Intercept;    
  $intercept->{Path} = $main::studio->Workspace->Path;
  $intercept->{Name} = $main::studio->Workspace->Name;
  map {$intercept->Item($_)->{Stub} = 1} (0..($intercept->Count - 1));
  $intercept->Create(); 

6. Add scripts to build and execute your application. If you are using a host-based simulator, examples of both are available from S2. If you are using actual devices, the steps required for building and starting the application are specific to the target environment.
7. Create one or more test classes to implement your C++ test logic. Click here for more information on creating test classes.
8. Ensure that the Studio workspace include path contains the location to all of your test class declaration (header) files.
9. Once you have created one or more test classes, save and compile the workspace.
10. [Optional] If your application is running, you can test-execute individual test classes interactively using the Studio interface view. To do this, open the user interface view corresponding to the test class you would like to execute, then call it. The return values will indicate how many tests produced each of four (4) result types. Furthermore, the input to the entry point will allow you to select all methods for execution (the default) or individual methods via a dropdown list of enumerated values.

• Once you are confident that the test classes are behaving as expected, you can generate one or more execution scripts using the Script Wizard. Sample templates for executing test class entry points are provided in the %STRIDE_DIR%\templates\Script Wizard directory.
• For integration with larger regression test workspaces, we recommend that engineers check in their test class code and, optionally, the template-generated scripts that can be used to execute their test classes.

Pragmas for test classes

STRIDE supports three pragmas for capturing and qualifying test classes:

• scl_test_class ( class ): Declares a test class as captured. Once captured, STRIDE will generate the appropriate code for executing the test methods in the class.
• scl_test_setup ( class , method ): [optional] Declares a member method to be a setup fixture for the class. If specified, the setup method will be called before the execution of each test method.
• scl_test_teardown ( class , method ): [optional] Declares a member method to be a teardown fixture for the class. If specified, the teardown method will be called after the execution of each test method.

C++ test class requirements

Several variations on typical xUnit-style test classes are supported. The additional supported features include:

• Test status can be set using STRIDE Runtime APIs or by specifying simple return types for test methods.
• Test writers can create additional child suites and tests at runtime by using Runtime APIs.
• We do not rely on exceptions for reporting of status.

The STRIDE test class framework has the following requirements of each test class:

• The test class must have a suitable default (no-argument) constructor.
• The test class must have one or more public methods suitable as test methods. Allowable test methods always take no arguments (void) and return either void or simple integer types (int, short, long, char or bool). At this time, we do not allow typedef types or macros for the return values specification.
• the scl_test_class pragma must be applied to the class.

Simple example using return values for status

 #include <srtest.h>
 
 class Simple {
 public:
   int tc_Int_ExpectPass(void) {return 0;}
   int tc_Int_ExpectFail(void) {return -1;}
   bool tc_Bool_ExpectPass(void) {return true;}
   bool tc_Bool_ExpectFail(void) {return false;}
 };
 #ifdef _SCL
 #pragma scl_test_class(Simple)
 #endif

Simple example using runtime test service APIs

 #include <srtest.h>
 
 class RuntimeServices_basic {
 public: 
   void tc_ExpectPass(void) 
   {
       srTestCaseAddComment(srTEST_CASE_DEFAULT, "this test should pass");
       srTestCaseSetStatus(srTEST_CASE_DEFAULT, srTEST_PASS, 0); 
   }
   void tc_ExpectFail(void) 
   {
       srTestCaseAddComment(srTEST_CASE_DEFAULT, "this test should fail");
       srTestCaseSetStatus(srTEST_CASE_DEFAULT, srTEST_FAIL, 0); 
   }
   void tc_ExpectInProgress(void) 
   {
       srTestCaseAddComment(srTEST_CASE_DEFAULT, "this test should be in progress");
   }
 };
 #ifdef _SCL
 #pragma scl_test_class(RuntimeServices_basic)
 #endif

Simple example using srTest base class

 #include <srtest.h>
 
 class MyTest : public stride::srTest {
 public:
   void tc_ExpectPass(void) 
   {
       testCase.AddComment("this test should pass");
       testCase.SetStatus(srTEST_PASS, 0); 
   }
   void tc_ExpectFail(void) 
   {
       testCase.AddComment("this test should fail");
       testCase.SetStatus(srTEST_FAIL, 0); 
   }
   void tc_ExpectInProgress(void) 
   {
       testCase.AddComment("this test should be in progress");
   }
   int tc_ChangeMyName(void) 
   {
       testCase.AddComment("this test should have name = MyChangedName");
       testCase.SetName("MyChangedName");
       return 0;
   }
   int tc_ChangeMyDescription(void) 
   {
       testCase.AddComment("this test should have a description set");
       testCase.SetDescription("this is my new description");
       return 0;
   }
 };
 #ifdef _SCL
 #pragma scl_test_class(MyTest)
 #endif

Runtime Test Services

The Runtime Test Services (declared in srTest.h) are a set of APIs in the STRIDE Runtime that facilitate the writing of target based test code. These APIs make up an optional portion of the STRIDE Runtime and can be used to communicate additional information about tests to the host based reporting mechanism. These APIs also allow target test code to create additional test suites and test cases dynamically at runtime.

The following C APIs are provided:

• srTestSuiteAddSuite: creates an additional sub-suite at runtime.
• srTestSuiteSetName: sets the name of the specified suite.
• srTestSuiteSetDescription: sets the description of the specified suite.
• srTestSuiteAddTest: creates an additional test case at runtime.
• srTestCaseSetName: sets the name of the specified test case.
• srTestCaseSetDescription: sets the description of the specified test case.
• srTestCaseAddComment: adds a comment to the specified test case.
• srTestCaseSetStatus: explicitly sets the status for the specified test case.

These C APIs work equally well from C test functions and C++ test classes. If, however, you choose to derive your C++ test classes from the STRIDE Runtime base class, srTest, then you will have access to member objects in srTest and their methods that provide the same functionality as the C API. The srTest base class provides two Member Objects, via which you can access functionality:

Member Objects:

• testSuite, which has methods:
  • AddSuite
  • SetName
  • SetDescription
  • AddTest
• testCase, which has methods:
  • SetName
  • SetDescription
  • AddComment
  • SetStatus

Refer to the Reference Guide or the Runtime Developers Guide, both available in the STRIDE Online Help, for detailed information about any of these functions.

Libraries/Components

There are several installed components that provide some of the core functionality for test class harnessing and execution. These components are installed and registered with the core product installation. The Test Class Component can be used for running test classes from scripts and the Test Class Codegen Component provides an interface for driving the test harness code generation (pre compilation) from script.

Sample Workspace

A sample workspace called TargetTestCode is installed with the STRIDE samples (an optional section when installing). This workspace not only includes several examples of test classes and functions, but also demonstrates several operational aspects of target-based verification. In particular, it demonstrates:

• How to call the preprocessor script before compilation by specifying the pre-compile workspace script. This is a convenient way to ensure that your test classes are properly captured before compiling your source code.
• How to use a host-based simulation application to run your test code. This allows the test developers to execute their tests in a simulation environment -- which is typically easier to build and execute -- before building and running their real target device. We provide a sample host application with this workspace.
• How to execute test classes and test functions from scripts. Two scripts are provided, one responsible for executing the test classes, the other for handling the test functions' execution. Both scripts were generated using the Script Wizard, using the variation that executes multiple interfaces in a single script. (For more information on the Script Wizard, refer to the STRIDE Online Help.)
• How to use several different styles of test classes and test functions within the STRIDE framework. We provide sample test classes that show how to use the srTest base class, as well as how not to use a base class and simply call the Runtime Test Services APIs directly. We also demonstrate how to use the Runtime Test Services from C-based test functions.

NOTE: This sample requires a path to standard C/C++ header files. The workspace is set to use the default include location for MS Visual Studio 2003. Users will need to change the include path for the TargetTestCode workspace to point to a different location if using a different version of Visual Studio.