Error Handling, Coverage

Owned by Mike Deskis
Last updated: May 03, 2024 by Ioana Kocurova
4 min read

Some interesting examples of error handling are discussed here.

Learning Objectives

The video discusses the importance of different types of data structures and control structures in programming. It explains the concept of coverage and different levels of coverage such as statement coverage, branch coverage, and multicondition coverage. The video also highlights the limitations of structural coverage in detecting errors and the need for error handling and testing for other risks.

 

Core Topics and Takeaways

  • Data structures

  • Control structures

  • Testing exceptions

  • Coverage

Video Highlights

Topic

Key Concepts

Video Location

Topic

Key Concepts

Video Location

Different types of data structures are optimized for specific operations and memory usage.

  • Data structures make certain searches and changes easier.

  • Control structures determine the flow of the program.

  • The sequence is a basic control structure that executes commands in order.

  • Branches evaluate logical expressions and execute different actions based on the result.

  • Loops repeat a sequence of commands.

  • Functions are self-contained tasks that can be used by other parts of the program.

  • Library functions are extensively used by programmers and are often pre-tested.

  • Exceptions are used to handle errors and abnormal situations in a program.

00:02

Exception handling that is not skillfully managed can cause hard-to-reproduce failures and interrupts are signals that some event has happened in a computer.

  • Exception handling doesn't have knowledge of what happened inside a method, it only knows that an exception occurred.

  • Interrupts are signals that indicate an event has occurred in a computer, and the computer responds by storing key data temporarily and running an interrupt handler.

  • Coverage in programming refers to how much of the code has been tested, usually expressed as proportions or percentages.

  • Structural coverage is a common approach to coverage, focusing on the program's flow of control and achieving 100% statement coverage means testing every statement in the code.

02:19

Achieving 100% branch coverage does not guarantee complete code coverage, especially when considering interrupts.

  • Interrupts in programs can cause control to shift to the interrupt handler at any time, leading to changes in the system state and potential failures.

  • Interrupts act as branches in the code, even though they may not be intentionally written as such by the programmer.

  • Structural coverage should take into account the presence of interrupts and not consider branch coverage as complete coverage.

04:41

Learning Highlights

The importance of different data structures, discussing their role in making searches and changes efficient. The video highlights the optimization of data structures for a balance between speed and memory usage. The focus shifts to control structures, explaining the sequence, branch, loop, and function as fundamental components. It introduces library functions and exceptions, emphasizing their impact on program states. The discussion moves to interrupts, describing how hardware and software interrupts can affect program execution. The section addresses the limitations of structural testing, particularly in detecting errors and risks. The importance of achieving high branch coverage for bug detection is acknowledged, but the effectiveness of structural tools for black-box testing is questioned.

Core Learning Concepts

Structural Testing

Structural testing, also known as white-box testing, involves testing the internal structure of a software application. This type of testing examines the code, architecture, and design of the software to ensure that it functions as intended. It focuses on testing individual components or modules to verify their correctness and assess code coverage. Structural testing techniques include statement coverage, branch coverage, and path coverage to ensure thorough testing of the code base.

The limitations of structural testing include inability to detect certain types of errors as structural testing may not effectively detect errors related to system integration, data flow, or performance. It may not cover all aspects of software behavior, such as error handling, boundary conditions, and exception scenarios. Despite achieving high structural coverage, some parts of the code may remain untested due to complex control flow and interactions. Structural testing may not provide a comprehensive understanding of how the system functions in real-world scenarios.

These issues state the need for additional testing approaches to ensure comprehensive software quality.

Black Box Testing (BBST)

Black box testing is a software testing method where the internal structure, design, and implementation of the system are not known to the tester. Instead, the tester focuses on testing the functionality of the software based on its specifications and requirements. This approach simulates how an end user would interact with the system, without considering its internal workings. The goal of black box testing is to identify discrepancies between expected and actual behavior, ensuring that the software meets its functional and non-functional requirements.

Since the internal structure of the software is not considered, it may result in incomplete code coverage. Black box testing may not effectively uncover certain types of defects related to code structure, data flow, and integration. The effectiveness of black box testing heavily relies on the accuracy and completeness of the system's requirements documentation. Without knowledge of the internal structure, diagnosing and fixing defects may be more challenging.

Structural vs. BBST

Both structural and black box testing are important for ensuring software quality. Structural testing focuses on the internal structure of the software, while black box testing examines its functionality based on specifications. A combination of both testing approaches is often recommended to achieve comprehensive test coverage and ensure the software meets its requirements and functions correctly.