Top 50 Ncover interview questions and answers

Table of Contents

1) What is code coverage analysis?

A code coverage analyzer monitors your code at runtime and records information about which lines of code were executed. NCover shows each sequence point in your application along with the number of times that point was executed. Sequence points are generated by the compiler and stored in the debug information (.pdb) files. A sequence point basically corresponds to a single program statement (often a line of code) in your high-level language.

2) Why would I want to do code coverage analysis?

Unit test suites are often used as a quality tool during the development process to keep the codebase stable as it changes and expands. Tools such as NUnit are often used to run and report on the test suites. However, when implementing unit testing in your build process, you have no way of knowing how much of your code the unit tests are actually testing. This is where code coverage comes in. You can run NUnit within NCover and use the code coverage report to determine which code was not tested by that particular test suite.

3) What makes NCover better than other code coverage tools?

Unlike most code coverage tools, NCover does not modify your source code in any way to generate coverage information. This means that you get coverage based on real, production code, providing more accurate data. For more information about how NCover works, see “Does NCover require a special compilation for my code?” and “How does NCover work?”

4) Which programming languages does NCover support?

In short, NCover supports any .NET programming language. NCover requires the .NET framework version 2.0.50727 to be installed; however, the application being profiled can be written against any shipping version of the framework. NCover has been tested profiling coverage of .NET 3.5, .NET 3.0, .NET 2.0 and .NET 1.1 applications. Note that NCover derives a lot of information from debugging symbols (.PDB files), which are not governed by any standard. This means that different languages and compilers will yield slightly different output.

5) Does NCover require a special compilation step for my code?

No. NCover is designed to work on shipping code by using the .NET Framework profiling API to monitor your code. It does require build symbols, but can be run on release code without any modifications. Note that debugging symbols may not be enabled by default in your particular programming environment. Changing this is typically as simple as adding an additional command line flag or project setting.

6) How does NCover work?

NCover uses the .NET Framework profiling API to monitor an application’s execution. When a method is loaded by the CLR, NCover retrieves the IL and replaces it with instrumented IL code. NCover does not change your original IL code; it simply inserts new code to update a visit counter at each sequence point. After the .NET process has shut down the profiler outputs statistics to the coverage file.

7) What kind of output does NCover produce?

By default, NCover outputs an xml file named coverage.xml. This file is the analysis output of NCover which you can load into NCover Explorer to see a graphical representation, including source code highlighting.

Another option available to Complete Edition users is the HTML output command line flag (//h). This generates a redistributable directory structure that can be viewed in any web browser.

8) What does the XML output look like?

Here is an example of the XML output:

9) Is there a graphical interface? A command line utility?

NCover provides both a graphical interface (NCoverExplorer.exe) and a command line utility (NCover.Console.exe) as well as a reporting tool (NCoverExplorer.Console.exe).

10) How do I use coverage exclusion attributes?

First you should define an attribute to markup your excluded code with. You will likely want to put this in a common assembly to make it reusable, or within a “CommonAssemblyInfo.cs” file that you include in all of your application assemblies.

{ { } }

Apply the attribute to the C# classes and/or methods you wish to mark as excluded from code coverage statistics

[CoverageExcludeAttribute]
{}
Finally, ensure you pass the full qualified attribute information in the NCover command line:

NCover.Console.exe MyApplication.exe //ea MyNamespace.CoverageExcludeAttribute
IMPORTANT: Note that if you are using the TestDriven.Net VS.Net add-in to “Test with Coverage” it will automatically pass through “//ea CoverageExcludeAttribute” which you should define without a namespace like above.

11) Can I use NCover with 64-bit programs? How?

If you are using the Enterprise Edition, yes. To profile 64-bit applications, you must have used the 64-bit installer, available from the download page. Otherwise, it is no different than profiling a regular 32-bit application.

12) Troubleshooting: Why don’t I get coverage for Automatic Properties?

Automatic Properties are syntactic sugar supported by the VS 2008 C# compiler. Unfortunately, the compiler doesn’t emit any symbols for Automatic Properties, so NCover (since it depends on the symbols generated by the compiler and placed in the PDBs) isn’t even aware that an Automatic Property exists. However, NCover does produce Branch Coverage for Automatic Properties. Unfortunately, NCover Explorer and the Full Coverage Report don’t highlight Branch Coverage in the source files.

13) Troubleshooting: Why is my coverage.xml file empty?

Your coverage.xml file is empty because NCover was unable to locate the debug symbol files for the assemblies profiled. This could happen because the assemblies were loaded from the GAC, in which case you should either uninstall the assemblies from the GAC, or move the .pdbs into the GAC.

One other reason NCover generates an empty coverage.xml file is because the assemblies were loaded from NUnit’s shadow copy. By default, NUnit shadow copies your assemblies before it tests them, and in some cases, the .pdb files aren’t copied with the assemblies. The easiest way to fix this problem is to run NUnit with the /noshadow command.

Finally, the //ssp argument might be too restrictive. Grant Drake has an excellent help page on empty coverage.xml files here.

14) Troubleshooting: I have coverage.xml output but my XYZ assembly is not included in it?

NCover will only profile loaded assemblies – did your code execution path force that assembly to be loaded (e.g. by loading a type or calling a method in that assembly)?
Did you generate build symbol files (.pdb files) for the missing assembly?
If using the //a option, did you correctly list the assembly names including the one that is missing?
Can you see information about the assembly being loaded within the coverage.log? Is the correct assembly being loaded (check the path) – if you have a version in the GAC it may possibly prevent the .pdb file from being loaded.
If using the NCover Explorer GUI, is a coverage exclusion defined causing it to be hidden from the display?

15) Troubleshooting: After running NCover my coverage.log says “Failed to load symbols for module XYZ”?

This message means that no .pdb build symbol file was found for that assembly so it cannot be profiled for code coverage. If that assembly is part of the .NET framework, for instance, the System.Data dll, then this is an expected message and should not cause concern. If however the assembly belongs to your application, did you generate the build symbol files (.pdb files) for it?

16) Is NCover free?

The company NCover, LLC began when the founder, Peter Waldschmidt, decided to commercialize the open source tool he created. … The commercial versions were launched in 2007, but the last supported free version 1.5. 8 is still available on the company site.

17) How do I run NCover?

To open NCover Explorer, click on the Start Menu, select All Programs, then NCover, and finally NCover Explorer. Now, open up Project Options by pressing Control-Shift-R or by clicking on Project Actions and choosing Project Options. This window is where you will get your tests ready to execute under NCover.

18) How do I use NCover in Visual Studio?

Install and Register the NCover Visual Studio Extension
Install/update NCover Desktop.
Select the available Visual Studio extension plug-in check box(es) to include with the Desktop install.
After Desktop is installed, open Visual Studio and confirm the NCover menu has been added to the Visual Studio main menu.

19) Which of the following is used for code coverage?

Code coverage tools are available for many programming languages and as part of many popular QA tools. They are integrated with build tools like Ant, Maven, and Gradle, with CI tools like Jenkins, project management tools like Jira, and a host of other tools that make up the software development toolset.

20) What is coverage criteria in software testing?

A coverage criterion is a rule or collection of rules that impose test requirements on a test set [Ammann, Offutt]. The coverage criterion describes test requirements completely and unambiguously.

21) How do I get code coverage in Visual Studio?

On the Test menu, select Analyze Code Coverage for All Tests. You can also run code coverage from the Test Explorer tool window.

22) What is coverlet collector?

Coverlet is a cross platform code coverage library for . NET, with support for line, branch and method coverage.

23) How does a coverlet work?

A coverlet is a bedcovering with sides that hang down a few inches past the box spring, but don’t touch the floor. A coverlet can be tucked in or left untucked if edged with decorative trim. Luxury coverlets can be layered directly over a flat sheet or over a blanket.

24) What is coverlet console?

coverlet.console. Coverlet is a cross platform code coverage framework for . NET, with support for line, branch and method coverage. It works with . NET Framework on Windows and .

25) What is coverlet MSBuild?

Coverlet is a cross platform code coverage library for . NET, with support for line, branch and method coverage. There are no supported framework assets in this package.

26) What is C# coverlet?

Coverlet is an open source project on GitHub that provides a cross-platform code coverage framework for C#. Coverlet is part of the . NET foundation. Coverlet collects Cobertura coverage test run data, which is used for report generation.

27) What is coverlet Nuget?

Coverlet is a cross platform code coverage library for . NET, with support for line, branch and method coverage. There are no supported framework assets in this package.

28) What is a coverlet vs quilt?

The main difference between a quilt vs coverlet is that coverlets do not have a middle layer of warmth as quilts do. Coverlets are made from a single piece of fabric. The fabric of quilts is in fact quilted, with three layers, but coverlets are not quilted.

29) Is a coverlet the same as a bedspread?

A bedspread is designed to cover the entire bed, up over the pillows, and down to the floor. Some bedspreads have a special pocket to hold a bedspread filler or top-of-bed insert for a plush look and additional warmth. A coverlet is smaller, designed to cover the top of the bed and to hang just past the boxsprings.

30) Can I use a coverlet as a bedspread?

If you are looking for a non-reversible cover to place over a comforter or bedspread set, a coverlet is thin and lightweight enough to layer with. You can use a coverlet on top of other pieces but keep it stand alone too for a minimal look.

31) Is a coverlet warm enough?

Adding a coverlet is the perfect finishing touch for a layered bedding look. However, the main downside to a coverlet bedding is that they are not as warm as other bedding options. They tend to be too thin to be the sole bedding topper, and should be paired with blankets or sheets for extra comfort.

32) What is a coverlet definition?

ˈkʌv ər lɪd/. a bed quilt that does not cover the pillow, used chiefly for warmth; bedspread. Archaic. any covering or cover.

33) What is test coverage in NUnit?

Coverage analysis of unit tests

For example, MSTest uses test-methods FQNs but NUnit uses properties of test attributes as test IDs. dotCover helps discover and run, debug or cover unit tests right in Visual Studio or using the command-line utility.

34) How do you view code coverage with coverlet and Visual Studio 2019?

The first step is to head to the Extensions menu and select Manage Extensions. Then, search Run Coverlet Report and install it – you have to close all Visual Studio instances to install it.

35) How do you create a code coverage report?

Generate the report
From the main menu, select Run | Generate Coverage Report, or click. in the Coverage tool window. …
In the Generate Coverage Report dialog, specify the directory in which the generated report should be stored, and optionally select the Open generated HTML in browser checkbox. …
Click Save.

36) What is SonarQube code coverage?

SonarQube is an open-source platform developed by SonarSource for continuous inspection of code quality to perform automatic reviews with static analysis of code to detect bugs, code smells and security vulnerabilities on 20+ programming languages.

37) What is JaCoCo and how it works?

JaCoCo is an open source toolkit for measuring code coverage in a code base and reporting it through visual reports.

38) What is JaCoCo test report?

JaCoCo reports help us visually analyze code coverage by using diamonds with colors for branches, and background colors for lines: Red diamond means that no branches have been exercised during the test phase. Yellow diamond shows that the code is partially covered – some branches have not been exercised.

39) Where is the JaCoCo report?

By default, a HTML report is generated at $buildDir/reports/jacoco/test .

40) How JaCoCo works internally?

Instrumentation requires mechanisms to modify and generate Java byte code. JaCoCo uses the ASM library for this purpose internally. Implementing the Java byte code specification would be an extensive and error-prone task. Therefore an existing library should be used.

41) What is missed branches in JaCoCo?

Missed complexity again is an indication for the number of test cases missing to fully cover a module. Note that as JaCoCo does not consider exception handling as branches try/catch blocks will also not increase complexity.

42) How do I run a JaCoCo report?

Show activity on this post. Run mvn jacoco:report it will generate coverage report. Open target/site/jacoco/index. html file to get pictorial view.

43) How do I check my JaCoCo code?

2.4 Open the target/site/jacoco/index. html file, review the code coverage report : Green – Code is tested or covered. Red – Code is not tested or covered.

44) How do I increase my JaCoCo coverage?

For the code coverage to increase , one would need to run the tests with the coverage enabled and then view the report generated locally to see the areas covered by jacoco during its coverage parse, then from these one would see the methods (per class) that needs to be covered from the view of the jacoco agent.

45) What does code smell mean in SonarQube?

SonarQube version 5.5 introduces the concept of Code Smell. According to Wikipedia and Robert C. Martin “Code smell, also known as bad smell, in computer programming code, refers to any symptom in the source code of a program that possibly indicates a deeper problem.

46) Does SonarQube require JaCoCo?

SonarQube is used in integration with JaCoCo, a free code coverage library for Java.

47) How do I fix duplicate codes?

How to remove duplicate code?
The same method, create the same Local Variable and reuse it.
The same class, create common Method refactoring.
Subclasses of the same hierarchy, you should Extract Method and Pull it Up.
Two different classes, you can use objects.

48) What is proper test coverage?

Calculating test coverage is actually fairly easy. You can simply take the number of lines that are covered by a test (any kind of test, across your whole testing strategy) and divide by the total number of lines in your application.

49) How is code coverage calculated?

How is it measured? To calculate the code coverage percentage, simply use the following formula: Code Coverage Percentage = (Number of lines of code executed by a testing algorithm/Total number of lines of code in a system component) * 100.

50) How many test cases are needed for coverage?

Condition coverage checks if both the outcomes(“true” or false”) of every condition have been exercised. The outcome of the decision point is only relevant for checking the conditions. It requires two test cases per condition for two outcomes.

51) How do I get code coverage in Visual Studio?