Improvements (9 items)
If you have suggestions for improvements, then please raise an issue in this repository or email me at markjprice (at) gmail.com.
- Page 6 - Setting up your development environment
- Page 24 - Setting up SQL Server and the Northwind database
- Page 29 - Creating a class library for entity models using SQL Server
- Page 156 - Understanding stack and heap memory
- Page 355 - Method injection example
- Page 385 - Naming unit tests
- Page 411 - Making fluent assertions in unit testing
- Page 497 - Page navigation and title verification
- Page 524 - Docker command-line interface (CLI) commands, Page 527 - Configuring ports and running a container
The bullet for Visual Studio currently says:
- Visual Studio: Visual Studio 2022 for Windows. (Visual Studio 2022 for Mac reaches end-of-life on August 31, 2024, and is not recommended.)
In the next edition, I will add a note that you could also use Visual Studio in a virtual machine, or use Microsoft Dev Box: https://azure.microsoft.com/en-us/products/dev-box.
A reader, @automaton posed a thought in the Discord channel for this book: "I wonder if the idea long term is to merge Code and VS."
@markjprice: "My best guess is that .NET developers on Windows will continue to prefer Visual Studio, and everyone else will prefer VS Code. Microsoft has been clear about their commitment to improving both Visual Studio and VS Code but keeping them distinct in their roles. While VS Code continues to be enhanced with new features and cross-platform capabilities, Visual Studio remains focused on being a best-in-class IDE for development on Windows. Visual Studio is deeply integrated with Windows-specific technologies and APIs. It leverages components such as the Windows Presentation Foundation (WPF), which is not natively supported on other operating systems. Rewriting or adapting these dependencies for other platforms would require significant effort and resources. Microsoft will never port Visual Studio to other platforms or merge the two products. Instead, they will continue to add features from each to the other e.g. Solution Explorer added to VS Code, and HTTP Editor added to Visual Studio."
In the next edition, I will add a note similar to the above explaining why Microsoft won't merge or replace either product any time soon.
Thanks to
CoericKfor asking a question in the book's Discord channel that prompted this improvement item.
@CoericK: "Hello @markjprice , I have a question, I'm running MacOS Catalina, according to your suggestions on page 24, your recommend to install Azure SQL Edge container for linux (i assume macos as well), https://github.com/markjprice/tools-skills-net8/blob/main/docs/sql-server/edge.md, however I already have an existing docker container running this image as base mcr.microsoft.com/mssql/server:2022-latest and installing mssqlserver via apt-get apt-get install -y mssql-server-fts, can I just use my existing container? or would it be better to follow along your instructions for this book using Azure SQL Edge?"
@markjprice: "You can use your existing container. Just be aware that the SQL script will create a database named Northwind in a schema named dbo. That shouldn't be an issue or conflict with any existing SQL objects that you have. I say to use SQL Edge partly to provide extra separation between what you'll do in the book, and what you might already have. "Use at your own risk." as they say. 🙂 You sound like you know what you're doing."
@CoericK: "Thanks Mark, I think that I will create an azure sql edge container, and run it at a different port, I assume I will have to customize the conection port where required"
@CoericK: "created it on port 1434, worked like a charm. I'm using Azure Data Studio on MacOS btw"
@CoericK: "i used this tool to generate the connection string https://www.aireforge.com/tools/sql-server-connection-string-generator"
@automaton: "My issue was with the Trust certificate in the connection string, something that isn't prompted necessarily though the VSCode extension."
@CoericK: "I'm on mac, So in order to follow along the guide I had to create a virtual machine with windows install visual studio a connect to thee db in the host machine, since I'm using SQL Server Edge I had to run this command to get the classes created on page 28
dotnet ef dbcontext scaffold "Data Source=HOSTNAME,PORT;Integrated Security=false;User ID=sa;Password=YOUR_PASSWORD;TrustServerCertificate=True;Initial Catalog=Northwind;" Microsoft.EntityFrameworkCore.SqlServer --namespace Northwind.EntityModels --data-annotations"
In the next edition, Tools and Skills for .NET 10, I will add notes about how to use existing SQL Server instances, how to customize the port number to avoid conflicts with existing container images, and tools like Azure Data Studio and websites for generating database connection strings. I will also add a note about trusting the certificate in the connection string too.
Thanks to OpticOrange and P9avel for raising this issue on October 13, 2024.
In Step 12, I wrote, "In Customer.cs, the dotnet-ef tool correctly identified that the CustomerId column is the primary key and it is limited to a maximum of five characters, but we also want the values to always be uppercase. So, add a regular expression to validate its primary key value to only allow uppercase Western characters, as shown highlighted in the following code:
[Key]
[StringLength(5)]
[RegularExpression("[A-Z]{5}")]
public string CustomerId { get; set; } = null!;"The phrase "limited to a maximum of five characters" is implemented by the dotnet-ef tool by adding the [StringLength(5)]. But what the tool cannot assume is that the rule should be more restrictive than a maximum. All CustomerId values should be five upper case characters. In the next edition, I will add more text to clarify:
"In Customer.cs, the dotnet-ef tool identified that the CustomerId column is the primary key and it is limited to a maximum of five characters by decorating the property with [StringLength(5)], but the tool did not make any further assumptions. We also want the values to always be uppercase and always exactly five characters. So, add a regular expression to validate its primary key value to only allow five uppercase Western characters, as shown highlighted in the following code:"
Thanks to P9avel for raising an issue on September 18, 2024 that led to this improvement.
At the start of the third paragraph, I wrote, "On Windows, for ARM64, x86, and x64 machines, the default stack size is 1 MB."
This sentence is correct.
Mark Russinovich is a Microsoft expert and he wrote a deep dive article about memory and threads that is worth reading. You can find it at the following link: https://learn.microsoft.com/en-us/archive/blogs/markrussinovich/pushing-the-limits-of-windows-processes-and-threads
Here are some relevant highlights:
Note that the 1MB limit is a default and that "developers can override these values". The .NET team decided to override the default so that .NET apps have 1.5 MB of stack memory, but this was a "completely accidental change", as you can read about in the following comment to a GitHub issue in the .NET repository: dotnet/runtime#96347 (comment)
"Prior to this change, we have been using the Windows native toolset default before that is 1MB."
If this issue might affect your projects, I recommend reading the following issue, especially the comments below from Microsoft employees who made the change from 1MB to 1.5MB: Migration from .NET Framework 4.7.2 to .NET 8 results in StackOverflowException due to reduced stack size.
Thanks to P9avel for raising this issue on September 29, 2024.
In the code example, I show a Minimal APIs endpoint defined using MapGet that requires a dependency service to be passed as parameter, as shown in the following code:
app.MapGet("/weather", (IWeatherService weatherService) =>
{
return Results.Ok(new { Weather = weatherService.GetWeather() });
});Often, the parameter will be decorated with [FromServices] but this is not necessary.
You don't always need to use the [FromServices] attribute when injecting services into an endpoint. Minimal APIs automatically resolve services from the dependency injection (DI) container if the parameter is of a service type that has been registered in the container. This implicit resolution happens based on the type of the parameter.
In the code example above, IWeatherService will automatically be resolved from the DI container without needing to use [FromServices].
However, if you want to explicitly signal that a parameter is coming from the service container or need to disambiguate in certain situations (for example, if a parameter could come from multiple sources like query strings, route data, or services), you should use [FromServices], as shown in the following code:
app.MapGet("/weather", ([FromServices] IWeatherService weatherService) =>
{
return Results.Ok(new { Weather = weatherService.GetWeather() });
});You may want to explicitly use [FromServices] in the following cases:
- Ambiguity: If there is ambiguity between where the parameter value comes from, for example, route parameters versus services.
- Explicitness: For code clarity and to signal that a parameter is explicitly being injected from services.
- Non-service types: If the parameter type isn't obviously a service, for example
HttpContext, ASP.NET Core might not infer it correctly unless you specify[FromServices].
In general, if the type is clearly a service and registered in the DI container, ASP.NET Core will resolve it without the attribute.
In the next edition, I will add this extra explanation.
Thanks to P9avel for raising this issue on October 2, 2024.
In this section, I try to explain that although, "[s]ome advocate for a standardized naming scheme for unit test methods, for example, [MethodName]_ [Scenario]_[Result], ..." "However, adopting a mechanical naming scheme like this is less useful than you might think ..." and therefore that I am NOT recommending that you prefix all your unit test names with [MethodName]_.
I also wrote, "Here are three examples of test names that use simple phrases in plain language:
Checkout_fails_when_item_is_out_of_stockUser_receives_confirmation_email_after_successful_registrationLogin_is_blocked_after_three_failed_attempts"
In the next edition, I will rewrite this section to make my point clearer, and I will use different examples here to make it clearer that Checkout_, User_, and Login_ are NOT method name prefixes.
In this section, I show how to use the FluentAssertions package. At the time of publishing, the latest version of this package was 6.12.0.
Since version 8.0.0, released on January 14, 2025, there has been a license change, as described at the following links: https://fluentassertions.com/releases/#800 and fluentassertions/fluentassertions#2943.
Comments from the owner dennisdoomen: "v7 will remain free indefinitely and will still receive critical fixes. v8 will only require a license when you use it in non-commercial projects." (fluentassertions/fluentassertions#2943 (comment) and fluentassertions/fluentassertions#2943 (comment))
In the next edition, I will recommend the use of v7.1 or later: https://www.nuget.org/packages/FluentAssertions/7.1.0
Alternatively, there is a v7-forked repo named AwesomeAssertions: https://www.nuget.org/packages/AwesomeAssertions/7.0.0. You should be able to replace the package reference and everything will continue to work.
In Step 5, I wrote, "Navigate to WebUITests\bin\Debug\net8.0 and, at the command prompt or terminal, install browsers for Playwright to automate, as shown in the following command:"
pwsh playwright.ps1 installA note links to the official Playwright guide for installing its custom browsers.
Playwright needs special versions of browser binaries to operate. You must use the Playwright PowerShell script to install these browsers. If you have issues, you can learn more at the following link: https://playwright.dev/dotnet/docs/browsers.
Some readers might get an error, The command “pwsh” is not recognized.
The most likely problem is that PowerShell is not installed properly on their computer (i.e. not installed at all, or installed but not set up so it is found from the command prompt).
In the next edition, I will add extra links to help readers who struggle with this, for example:
Install PowerShell on Windows, Linux, and macOS https://learn.microsoft.com/en-us/powershell/scripting/install/installing-powershell
Some of the answers here might help: getting started instructions dont work #1865: microsoft/playwright-dotnet#1865
Page 524 - Docker command-line interface (CLI) commands, Page 527 - Configuring ports and running a container
Thanks to P9avel for raising this issue on October 10, 2024.
In Table 15.4, I give an example of a Docker command to run an image, as shown in the following command:
docker run -d -p 8080:80 --name webapp mcr.microsoft.com/dotnet/aspnet:8.0
Although the example image path is valid (see: https://hub.docker.com/r/microsoft/dotnet-aspnet), that image only contains the ASP.NET Core Runtime without an app, so it's not a useful example. That image is designed to pulled and then added to with your own project.
A better example would be one that also contain a sample app so that you have something to interact with immediately, as shown in the following command:
docker run -d -p 8080:80 --name webapp mcr.microsoft.com/dotnet/samples:aspnetapp:8.0
Similarly, on page 527, I show an example of setting ports, as shown in the following command:
docker run -p 8000:8080 -d --name myaspnetapp mcr.microsoft.com/dotnet/aspnet:latest
Although the specific image used is not important because it's just showing how to set ports, a better example would use the image with an app, as shown in the following command:
docker run -p 8000:8080 -d --name myaspnetapp mcr.microsoft.com/dotnet/samples:aspnetapp:latest
And on page 528, I show an example of configuring for HTTPS. The example would be better with the sample app image, although again, the point is not the specific image, it's just to show the additional switches for configuring HTTPS.