Solve real coding problems
Problem When you go to configure authentication in IIS Manager, you notice that Windows Authentication is missing from the list of available authentication methods. You have to enable IIS Windows Authentication using the Windows Features tool (or in Server Roles if you’re using Windows Server). Solution The precise instructions for enabling IIS Windows Authentication vary … Read more
Problem The Class Diagram item is missing in Visual Studio. Note: I ran into problem starting in VS2019. Solution For some reason this is not installed by default in Visual Studio, so we simply need to install it. 1. In Visual Studio click Tools > Get Tools and Features… 2. Close Visual Studio. 3. In … Read more
The Large Class code smells refers to a class that has too many responsibilities. It’s doing too much. Ideally a class should only have one responsibility (Single Responsibility Principle). Code Smell: Large Class Definition: A class has too many responsibilities. Solution: Identify all of the distinct responsibilities of the Large Class. For each responsibility, extract … Read more
The number one rule when refactoring is to always have tests in place before you start refactoring. Without tests, refactoring becomes a risky endeavor. Code that doesn’t have tests is often not designed to be testable. In order to make the code testable, you have to refactor it. See how this seems like an impossible … Read more
Problem When I execute a SQL query I’m getting the following error: Conversion failed when converting date and/or time from character string. The query is using ORDER BY with CASE with a passed in parameter called @OrderBy. Solution Use a separate CASE statement for each possible value (instead of one CASE with multiple WHENs).
In this article I’ll be walking through an example of how to refactor the Long Method code smell. Code Smell: Long Method Definition: A method has too many lines of code, making it hard to understand. Solution: Long Method code smell example Here’s an example of the Long Method code smell (source: GildedRose Refactoring Kata). … Read more
Problem I have a unit test project in Visual Studio 2019. When I click Run All Tests, none of the tests run. I looked in the Tests output window and saw a message that says: Test project does not reference any .NET NuGet Adapter. Test discovery or execution might not work for this project. It’s … Read more
In this article we’ll use Spring Boot to create an endpoint that polls an Amazon Simple Queue Service (SQS) queue for messages. Messages will consist of famous quotes saved to the database as they’re received. Amazon SQS and Spring Series This article is part of a series: Set up the database Prerequisites You must have … Read more
In this article we’ll use Spring Boot to create an endpoint that can send messages to an Amazon Simple Queue Service (SQS) queue. In our application messages will consist of famous quotes. Amazon SQS and Spring Series This article is part of a series: Create a class for the quote message The following Data Transfer … Read more
In this article we’re going to create a Spring Boot project using Spring Initializr that will allow us to interact with Amazon SQS queues. Amazon SQS and Spring Series This article is part of a series: Create a new Spring Boot project using Spring Initializr Dependencies Open the pom.xml file to review the dependencies. The … Read more
Problem When I open a C# project in Visual Studio 2019, none of the references are loading. In the error list it says “The referenced component could not be found” for several references. Here’s a snippet showing just a few of the reference errors: The referenced component ‘System’ could not be found.The referenced component ‘Microsoft.CSharp’ … Read more
In this article we’re going to create a queue in Amazon Simple Queue Service (SQS) using an AWS Stack template. Amazon SQS and Spring Series This article is part of a series: What is a message queue Message queues allow different parts of a system to communicate and process operations asynchronously. A producer sends a … Read more
In regex, capturing groups give you a way to save text and refer to it later. Capturing groups can be named, and referred to by their name. When they aren’t named, you refer to them by their index number. In this article, I’ll show how to use named capturing groups by solving the problem of … Read more
Companies like to ask you to solve whiteboard problems during coding interviews. If it’s an in-person interview, they’ll ask you to solve the problem on a physical whiteboard. If it’s a remote interview, they’ll either have you solve the problem on a website like HackerRank, or they’ll ask you the question in a “digital whiteboard” … Read more
You need to auto-increment your build numbers in order to easily tell which code you’re working with. In this article I’ll explain how to auto-increment your build numbers in Visual Studio. I’ll be using text templating to generate the Assembly Version. 1 – Choose a versioning scheme I’m going to be using the version scheme: … Read more
Problem You’re trying to debug a program with Visual Studio but Attach to Process does not work. Most likely you’re loading your code through some third-party process (like Excel), and when you try to use Attach to Process it simply doesn’t work. Solution Instead of trying to use Attach to Process, you can launch a … Read more
Problem statement: Given a 32-bit signed integer, how many set bits are there? Ex: The number 15 has four bits set. In this article I’ll explain how I’d approach this problem. Approach How do I know if a bit is set? A bit can either be 0 or 1. A bit is set if its … Read more
The need to mock static methods in order to add a unit test is a very common problem. It’s often the case that these static methods are in third-party libraries. There are many utility libraries that are completely made up of static methods. While this makes them very easy to use, it makes them really … Read more
With the Producer/Consumer pattern you have one or more threads producing new work and enqueuing it, and one or more threads consuming that work by dequeuing it and processing it. The consumers and producers share access to the work queue. Think of it like the Post Office. You have one or more people (producers) dropping … Read more
Problem You have a SQL query like this: While executing this you get the following error: ‘CREATE/ALTER PROCEDURE’ must be the first statement in a query batch Solution The error message says it all: the CREATE PROCEDURE statement cannot be executed after other queries in the same batch of queries. The solution is to execute … Read more
Problem I’m trying to use Selenium with the ChromeDriver and I’m running into the following exception: Unhandled Exception: OpenQA.Selenium.DriverServiceNotFoundException: The chromedriver.exe file does not exist in the current directory or in a directory on the PATH environment variable. The driver can be downloaded at http://chromedriver.storage.googleapis.com/index.html Solution The simplest solution is to install the Selenium.Chrome.WebDriver package: … Read more
Problem I am using Selenium (in C#) to automate navigating a website. I’m trying to click a button: When I try to click the button it’s throwing the following exception: OpenQA.Selenium.WebDriverException: Element is not clickable. Other element would receive click. The reason this is happening is because Selenium is trying to click the button by … Read more
Sometimes you need to diff two branches and your source control system isn’t the right tool for the job. One option is to use WinMerge to diff the branch folders and then look at the diffs visually in the UI. I’ll show how to do that. 1 – Example – Old Branch and New Branch … Read more
How do you check for new records in a database and react to the new data? You really only have two options: Poll for changes every X seconds Use query notifications to be notified when new data is inserted In this article I’ll show you how to configure query notifications so that your application receives … Read more
Events are an implementation of the observer pattern and consists of two parts: There are three simple steps to using events, which I’ll show below. 1 – Add an event field The first step is to add an event field to a class with the event keyword and a delegate type (such as the generic … Read more
