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

The C++ test class support described here only works in STRIDE version 2.1.0000 or later. The host PC must also have a recent distribution of ActiveState perl installed.

How to get started

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

1. Create a new Studio workspace (or open an existing one).
2. Set the workspace to compile in C++ mode(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\TestClasses\TestClass_Preprocess.pl (or .js) to your Workspace General Pre-Compile Script property (Highlight "Workspace" and look under Property). 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. Set 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 %STRIDE_DIR%\scripts\TestClasses\TestClass_Preprocess.pl (or .js) for this purpose. Set the script to your Workspace General Post-Compile Script property (Highlight "Workspace" and look under Property). If you need to customize the name and/or location of the generated Intercept Module simply create your own version of this script.
6. Add scripts to build and execute your application. If you are using a host based simulator, we examples available of both. 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. See below for more information on creating test classes.
8. Ensure that the Studio workspace include path has the location to all of your test class declaration (header) files.
9. Once you have created one or more test classes, save the workspace and simply compile the workspace.
10. [Optional] If your application is running, you can test execute individual test classes interactively using the Studio interface view. Open the user interface view corresponding to the test class you would like to execute and call it. The return values will indicate how many tests produced each of 4 result types. Furthermore, the input to the entry point will allow you to select all methods or execution (the default) or individual methods -- this is done 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.

C++ test class requirements

We support several variations on typical xUnit-style test classes. The additional features we support 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(MyClass)
 #endif

Runtime Test Services

The Runtime Test Services 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. This API also allows 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 methods in srTest that provide the same functionality as the C API. Furthermore, the srTest class actually provides two simple mechanisms to access this functionality:

1. Member Methods:
   • testSuiteAddSuite
   • testSuiteSetName
   • testSuiteSetDescription
   • testSuiteAddTest
   • testCaseSetName
   • testCaseSetDescription
   • testCaseAddComment
   • testCaseSetStatus
2. Member Objects:
   • testSuite, which has methods:
     • AddSuite
     • SetName
     • SetDescription
     • AddTest
   • testCase, which has methods:
     • SetName
     • SetDescription
     • AddComment
     • SetStatus

See the STRIDE Reference guide 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.

STRIDE.testclass

The STRIDE.testclass component is used for executing test classes. It handles the underlying communication with the runtime and creates results in a specified reporter suite. This object supports the following properties and methods:

• ascript : Input only. This is the ascript instance for the current execution environment. This is required prior to calling the run method. In most cases, you can simply pass the global ascript instance from your script that executes in your workspace.
• parentSuite : Input only. This is a reporter suite object into which results for the test class should be added. A sub-suite corresponding to the test class will be created in the given parent suite and all test method results will be added to this new child suite. This is required prior to calling the run method. This suite will also serve as the default suite during execution, into which dynamic entities will be placed when srTEST_SUITE_DEFAULT is specified.
• dataFile : Input only. This specifies the name/location of the test class meta-data file (generated by the preprocessing step). This is required prior to calling the run method.
• run : Method. This initiates the running of the specified test class object. This method requires a single argument -- the name of the test class entry point function that was generated by the preprocessing step.

STRIDE.testclass_codegen

The TestClass_Preprocess.pl/js script demonstrates how to invoke the functionality exposed in the STRIDE.testclass_codegen object. This object exposes the following properties and methods:

• exceptions : Input only. Indicates whether or not to generate exception handling code in the test class entry point functions. If you do not have exceptions enabled on your target, set this to 0 -- otherwise we recommend you set it to 1 to enable exception handling code in the test class entry point.
• outFile : Input only. The name/location of the generated file. This will default to a file named {WORKSPACE}TCR.cpp (where {WORKSPACE} is the name of the current workspace) and will be located in the workspace directory.
• dataFile : Input only. The name/location of the meta-data file generated by the preprocessor. This meta-data is used by the STRIDE.testclass library to determine the name of test classes and methods as they execute. The default name for this file is {WORKSPACE}.tcrd, located in the workspace directory. If you override this property, be sure to override the same property in STRIDE.testclass wherever it is called.
• studio : Input only. This is the automation object interface to the current execution environment. In most cases, you can simply pass the current global studio object from the script in your workspace. This is required prior to calling generate.
• generate : Method. Call this method when you are ready to generate the test class entry points.

Script Templates

There are several installed script templates for use with the STRIDE Studio Script Wizard functionality. These templates provide a way to invoke the STRIDE.testclass object for particular test class entry point functions.

There are two variants of the the template scripts for test classes. The TestClass_Multiple templates are intended for use in running multiple test class entry point functions with a single script. The set of functions is stored in an array (generated by the Script Wizard) and execution merely iterates over the set. The TestClass_Single templates can be used for creating a script to execute a single test class entry point.

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 also demonstrate one way to automatically build the host based simulator using Microsoft Visual Studio.
• How to execute test classes and test functions from scripts. Two scripts are provided, one responsible for executing the test classes, the other handles the test functions execution. Both scripts were generated using the Script Wizard, using the variation that executes multiple interfaces in a single script.
• How to automatically start and stop an application when testing. This example uses the host based simulator described above. Scripts are provided that launch this application prior to running the tests and close the application after the tests are completed.