BUG DETECTION USING ASSERTIONS in Java

Encode QR Code in Java BUG DETECTION USING ASSERTIONS
BUG DETECTION USING ASSERTIONS
Reading QR In Java
Using Barcode Control SDK for Java Control to generate, create, read, scan barcode image in Java applications.
You ll notice that the assertion macros do not panic by default, but allow you to specify what procedure to call should the assertion fail This gives you more control, but you should always terminate the running code and ag up the failure, rather than return an error or leave Assertions help you detect invalid states or bad program logic so you can x your code as early as possible It makes sense to stop the code at the point of error, thus forcing you to x the problem (or remove the assertion statement if your assumption is invalid) If the assertion simply returns an error on failure, not only does it alter the program ow, but it also makes it harder to track down the bug You should always raise a panic when an assertion statement fails
QR Code Maker In Java
Using Barcode encoder for Java Control to generate, create Quick Response Code image in Java applications.
ASSERT DEBUG
QR-Code Reader In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
Here s one example of how to use the debug assertion macro:
Drawing Bar Code In Java
Using Barcode drawer for Java Control to generate, create barcode image in Java applications.
void CTestClass::TestValue(TInt aValue) { #ifdef _DEBUG _LIT(KPanicDescriptor, "TestValue"); // Literal descriptor #endif __ASSERT_DEBUG((aValue>=0), User::Panic(KMyPanicDescriptor, KErrArgument)); }
Reading Barcode In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
Of course, this is somewhat awkward, especially if you expect to use a number of assertions to validate your code, so you ll probably de ne a panic utility function for your module, with its own panic category string and a set of panic enumerators speci c to the class So, for example, you d add the following enumeration to CTestClass, so as not to pollute the global namespace:
Encoding QR Code ISO/IEC18004 In Visual C#
Using Barcode creator for Visual Studio .NET Control to generate, create Quick Response Code image in .NET framework applications.
enum TTestClassPanic { EInvalidData, // =0 EUninitializedValue // =1 };
Creating Denso QR Bar Code In Visual Studio .NET
Using Barcode drawer for ASP.NET Control to generate, create Denso QR Bar Code image in ASP.NET applications.
Then de ne a panic function, either as a member of the class or as a static function within the le containing the implementation of the class:
Generating QR-Code In VS .NET
Using Barcode encoder for VS .NET Control to generate, create QR-Code image in VS .NET applications.
ASSERT DEBUG
Drawing QR Code ISO/IEC18004 In Visual Basic .NET
Using Barcode maker for .NET framework Control to generate, create Quick Response Code image in VS .NET applications.
static void Panic(TInt aCategory) { _LIT(KTestClassPanic, "CTestClass-Panic"); User::Panic(KTestClassPanic, aCategory); }
Print Code 128 Code Set C In Java
Using Barcode creator for Java Control to generate, create Code 128 Code Set A image in Java applications.
You could then write the assertion in TestValue() as follows:
Encoding UPC-A Supplement 2 In Java
Using Barcode creator for Java Control to generate, create UPC A image in Java applications.
void CTestClass::TestValue(TInt aValue) { __ASSERT_DEBUG((aValue> =0), Panic(EInvalidTestValueInput)); }
Bar Code Encoder In Java
Using Barcode generation for Java Control to generate, create barcode image in Java applications.
The advantage of using an identi able panic descriptor and enumerated values for different assertion conditions is traceability, both for yourself and clients of your code, when an assertion fails and a panic occurs This is particularly useful for others using your libraries, since they may not have access to your code in its entirety, but merely to the header les If your panic string is clear and unique, they should be able to locate the appropriate class and use the panic category enumeration to nd the associated failure, which you will have named and documented clearly to explain why the assertion failed There may be cases where there s nothing more a client programmer can do other than report the bug to you, the author of the code; alternatively, the problem could be down to their misuse of your library, which they ll be able to correct I ll discuss the pros and cons of using assertions to protect your code against badly-programmed calling code later in this chapter If you don t want or need an extensive set of enumerated panic values, and you don t expect external callers to need to trace a panic, you may consider using a more lightweight and anonymous assertion A good example of this is to test the internal state of an object, which could not possibly be modi ed by an external caller, and thus should always be valid unless you have a bug in your code Assertions can be added early in the development process, but left in the code, in debug builds, to validate the code as it is maintained and refactored In these cases, you may consider using the ASSERT macro, de ned in e32defh as follows:
ITF-14 Creator In Java
Using Barcode encoder for Java Control to generate, create EAN / UCC - 14 image in Java applications.
#define ASSERT(x) __ASSERT_DEBUG(x, User::Invariant())
Printing UPC-A Supplement 2 In .NET
Using Barcode printer for .NET Control to generate, create UPC-A image in VS .NET applications.
I like this macro because it doesn t need you to provide a panic category or descriptor If condition x is false, in debug builds only, it calls User::Invariant() which itself panics with category USER and reason 0 The macro can be used as follows:
Print Barcode In .NET
Using Barcode creator for Visual Studio .NET Control to generate, create bar code image in Visual Studio .NET applications.
Bar Code Maker In .NET
Using Barcode generation for ASP.NET Control to generate, create bar code image in ASP.NET applications.
Making Bar Code In Visual C#
Using Barcode generation for Visual Studio .NET Control to generate, create bar code image in .NET applications.
European Article Number 13 Scanner In Visual Studio .NET
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in VS .NET applications.